Maxim X Radiator Fan Switch Modification (UPDATE)

Hi,
Sorry if this is a topic that's been covered. I picked up an '85 Maxim X last weekend; for some reason the previous owner had wired in a toggle switch (taped next to the ignition key slot) to turn the radiator fan on / off. Does anyone have any idea why someone would do this? I'd like to revert it back to the stock condition, but have no idea where to begin since I don't know how the system functioned originally. I'm interested in any thoughts on the matter.

Thanks!
-steve

 

Re: Unwanted Maxim X Radiator Fan Modification

Steve,

The previous owner had one of two reasons for putting in the switch. The first would be that the Thermo Switch (located on the thermostat housing) was not switching on the fan at higher temps. The other being that they wanted to have control over when the fan came on. Typically you would turn it on manually when the engine is at a lower operating temp if you get stuck in traffic.

Does the fan work when you switch it on manually? If so, and if you wish to revert back to the stock setup, you'll have to patch up the wiring then check to see if the thermo switch operates. It should switch on the fan between the middle mark and the red line on your temp gauge.

Tony

 

Re: Unwanted Maxim X Radiator Fan Modification

Tony,

thanks for the feedback! Yes, the fan works (ingnition ON, toggle ON). For now, I'll use your guidance to switch the fan on at the right time. I'm going to try to patch up the wiring, as soon as I figure out how it's all supposed to be routed; I wish I had an example to look at. I'll look around for a service manual first.

FYI, here is a picture of the switch mod, and the bike itself (I'm pretty happy with the purchase )

-steve

 

Re: Unwanted Maxim X Radiator Fan Modification

The fan normally kicks on when the temp needle gets up into the red zone, so you could wait and see if it kicks on by itself. I was under the impression that people who made this mod wired the switch in parallel so it could be removed later.

Chacal has them, last I checked. Ask for part number HCP1145.

 

Re: Unwanted Maxim X Radiator Fan Modification

That bike looks real nice. Same color as the 85 700x I sold in June.

BTW, make sure your tires and brakes (front and rear) are safe. Even though they may look good (check the date codes on the tires) as you may have to replace some items to be sure.

On the fan issue, it's best to have a manual with a wiring diagram. That will also have a flow chart on how to check the fan operation.

 

Re: Unwanted Maxim X Radiator Fan Modification

Thanks everyone for the advice and safety tips. Going to do a top down overcheck of all systems before any serious riding (that's what's winter is for, right?). She's a good runner though, and I couldn't go wrong picking up a Maxim X with 9K miles for $1900.

This fan switch is goofy; it's wired such that when the key is on (engine running or not) you can manually switch the fan on/off. I'm inclined to agree with Tony that the thermo-switch went bad and this was a workaround - can't tell for sure though because the thermo-switch appears to have been bypassed (service manual to the rescue!). In case anyone's curious, I pulled off the front fuse panel and took another pic of the hack job. Anyone know what the top right 30A fuse is for (where the red lead is spliced in)?

 

Re: Unwanted Maxim X Radiator Fan Modification

That fuse is for the Signals and it's marked on the inside of the fuse cover. BTW, it should be a 15Amp fuse. I guess they wanted to connect up to a "Hot with the key on" point where they could splice it in.

Kinda frustrating when you discover stuff like that. Just makes you want to get started on your "Winter project" sooner so that you can sort out all the stuff that needs attention.

 

Re: Unwanted Maxim X Radiator Fan Modification (update)

UPDATE: After spending some more time researching the forums, I owe the previous owner an apology (and a big thank you for selling me his garaged, rust free, super clean XJ700XN with only 9K miles!). Turns out that adding a manual radiator fan switch to these bikes is fairly common; in fact there are several posts describing how to do it. By design, the thermo switch doesn't signal the fan to kick on until the temperature gauge is just touching the red zone; which is fine for cruising speeds, but can be disconcerting when sitting in traffic while the temperature hovers near the red line. The manual switch allows you to have more control over the engine temperature in these situations.

That being said, I didn't like having a switch taped onto the handle bars, and decided to try something I saw on the V-Max forums (apparently they suffer from the same issue): replace the stock thermo switch (Yamaha OEM part number 2EL-82560-00-00) with an aftermarket switch that signals the fan to come on at a lower temperature (about 20 degrees cooler).

First, I pulled out the manual switch installed by the previous owner, installed the proper 15 amp fuse in the upper right slot (thanks xHondaHack for noticing this), and rewired everything to the original condition. Fired it up, relaxed with a cold beverage and watched closely. Sure enough, right at the redline the fan kicked on (it's easy to see with a flashlight from behind the radiator), thus everything was working as designed. Could have stopped there but decided to take it one step further.

****Disclaimer*** read on only if you're curious...this is not a recommendation to modify a perfectly functioning bike (if it ain't broke...you get the point)...

From the V-Max forum I learned that the fan switch for the 1988 Nissan Sentra fits the Maxim X, and sends a signal at a slightly lower temperature, providing additional cooling margin. For around $20 bucks, I purchased the Wells SW537 switch. The male connector on the aftermarket switch isn’t compatible with the female one on the bike, but it was easy to modify to make it fit. In the photo, you can see the aftermarket thermo switch (after I cut off the Nissan male connector), and the flat electrical connectors that I soldered on to get it to work with the Maxim X.

After preparing the switch, next I drained the radiator, removed all the hoses from the thermostat housing, and pulled the housing (the service manual comes in handy here). With the thermostat housing sitting on the work bench, it was easy to remove the stock thermo switch and install the aftermarket one. It was also a good opportunity to remove the thermostat and check the functionality (again, according to the instructions in the service manual).

Putting everything back together was fairly smooth, except that the new switch sticks out a little bit further than the stock one, so it took awhile to find the perfect angle to fit the thermostat housing back into the frame.

I flushed the radiator, refilled with coolant, crossed my fingers and fired it up. I'm pretty satisfied with the results; the fan now switches on when the temperature indicated on the gauge is at the 12 oclock position. When cruising, the bike runs at the same temperature as before, but stays away from the red zone when idling in traffic.

 

Re: Unwanted Maxim X Radiator Fan Modification

here's a photo of the position of the temperature gauge just before the fan kicks on with the lower temperature thermo switch installed. It ultimately goes a bit higher than this, but stays well away from the red zone.

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

Hey Pick......nice job there. Contact Len Chacal at XJ4Ever, and make sure he sees this procedure. Looks like you may have a winner there for a good write-up for his site and/or for the xjcd, too.

Dave Fox

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

Nice setup with the new switch. Now you won't have to worry about switching the fan on manually.

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

sent a PM to Mr. Chacal. And yes, it will come in handy, especially during our blast furnace summers here in the eastern washington desert

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

This is a great mod for the X thanks for doing the leg work, it's something I think I'll try. Do you have any pics of the swith mounted?

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

X2 - add a few more pics and you'll be golden!

good work!

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

I've had this concern with my bike since I've owned it. The whole waiting for the fan to kick on so late while in traffic is stressful. I'm gonna have to do this one

 

Re: Unwanted Maxim X Radiator Fan Modification (UPDATE)

Sorry for not taking more pics during the job. You can get the basic idea from the Parts List (see picture below). The thermo switch (part 13) threads into the thermostat housing (you have to pull the thermostat housing to get to the switch).

The original yamaha stock switch has two male connectors that plug into the two female connections on socket cord assembly (part 15) which is part of the bikes electrical system. The aftermarket Nissan switch has a large plastic connector that I cut off and then replaced with some fittings that were close in shape and size to the male connectors on the stock switch. The modified Nissan switch will now plug directly into the bike's socket cord assembly.

The good thing about this approach is that you do not have to modify any of the OEM parts in any way; that way, if you need to, you can put it back the way it was (you did read my disclaimer, right?)

 

Re: Unwanted Maxim X Radiator Fan Switch Modification (UPDATE)

That makes it a lot clearer and esier to understand.
Great work!

 

Re: Unwanted Maxim X Radiator Fan Switch Modification (UPDAT

Thanks for this. I have been considering the manual switch for some time, but didn't want to add a cheezy switch. This will provide the safety margin desired in a non-obvious way.

 

Re: Unwanted Maxim X Radiator Fan Switch Modification (UPDAT

Thanks for the pictures and description on the how to. Looks to be a simple enough mod and I think I'll be doing it as well.

 

Re: Unwanted Maxim X Radiator Fan Switch Modification (UPDAT

Since folks are going to try this, I want to make clear that I’m no mechanic, so please be thorough and cautious - modify at your own risk!!. Along these lines, some thoughts for discussion:
1) you can plug the thermo switch in two ways. From my limited knowledge of electronics, based on where it is in the circuit, I don't think it should matter which way the thermo switch gets plugged into the socket cord assembly. I only tried it one way, and it worked. The fan should draw air through the radiator toward the engine; that is spin counterclockwise when looking at the fan from behind the radiator.
2) Why did Yamaha design it this way in the first place? There is surely an optimum operating temperature for the engine. From what I've seen, the lower temperature switch mod doesn't change the temperature when cruising, which kind of makes sense because a lot of air is being pushed through the radiator with or without the fan running. With the switch mod, the engine temperature is maintained at the cruising speed value ALSO when idling; which I perceive as being a good thing. I feel better looking at that temperature gauge and seeing it hold steady at 12 oclock high.
There is also this piece of information from the XJ700XN Owners Manual: "Engine Temperature Gauge: This gauge indicates the coolant temperature when the main switch is ON. The engine operating temperature will vary with changes in weather and engine load. If the needle points to the red zone or higher, stop your motorcycle and let the engine cool. Caution: When the engine is overheated, do not continue riding"
3) I used the o-ring provided with the aftermarket Wells switch; I'm not sure if it is the same as the one originally supplied with the bike. I used a LITTLE bit of high temp RTV around the seal and threads just in case. I don't know if that was good or bad, but there are no leaks; so at least that's good.
4) pay attention to how you remove the thermostat housing from the frame, it's a tight fit and the orientation is key. You'll reverse the procedure to get it back in. Also move all the radiator hoses well out of the way, you'll need the room.
5) the blue electrical connectors I used were slightly larger than the gauge wire used on the Wells switch. I pinched them on with needle nose pliers and then soldered the wires in, so it was good and secure. Perhaps you can find similar connectors with a slightly smaller diameter to fit the wire better.
6) if anyone tries this and finds a better / easier way, please share.

 

Great post! I have been riding my maxim x since I bought it in November. Sitting in traffic the eng warms up and I can hear the fan kick on but only when the gauge reaches near the red zone. Very uncomfortable feeling! I will be working on this mod very soon. Thanks for posting this! Here in NC it's been fairly cool but I know it's going to get warmer soon and I just want to make sure my bike will run just a little bit cooler. Again, thanks for taking time to post your experiences!
Ride safe!!

 

Getting ready to do this mod myself, and wanted to provide a tip for all here.

I had tried to source the switch (Wells SW537) for the '88 Nissan Sentra through the local NAPA store. They wanted $67. ??? and it had to be ordered.

So being that I buy a lot of parts from RockAuto.com for all of my other vehicles, I decided to check there. What I found by using their drop down list for the 1988 Sentra / Electrical / Switches & Relays / Radiator Fan Switch = the equivalent switch for under $11. Of course you'll have to add the shipping cost to wherever you located.

Hope this helps.

Tony

 

WOW they must have heard it was multi-application and raised the price!

Just to clarify something from above, it doesn't matter which way the switch is connected, all it does in effect is short one wire to the other & allow current to flow.

 

I mentioned earlier that this looked like a good project, but I am a little put off by the cost of the mailing/shipping charges. I went to the Rockauto.com (thanks Tony) to check it out and for the costs to ship to a Michigan Zip was about 1 tenth the cost to Canada! The Fed Ex and UPS were a bit cheaper but using couriers can add more at the pick up point for brokerage fees (only happened once, never again) which can be rediculous.
Here's a "snip" for the U.S. costs


Here's one for the Canadian

 

What, they charge more for the same part too? 10.80 Vs 11.09 8O


And that shipping is just crazy, surely it'd be cheaper for a member to buy it in the US & then "send a gift to a friend in Canada"?

 

I'm sure there are other manufacturers making the same switch for cheaper (doesn't help with the shipping problem for sure!). I got the Wells at Autozone (I just asked for an '88 Nissan Sentra switch and it's what they had, ~20 bucks last fall). What is important is the temperature setpoint and the thread gauge; which should be consistent across manufacturers provided the switch is designed for the '88 Nissan Sentra. Also, due to the tight clearances I mentioned, make sure it fits first before you cut any of the leads.

Thanks for the feedback, and please keep posting any pictures, improvments, lessons learned to help others.

*****************
(I went back and read Tony's post more carefully and saw that he found a switch for $11 + shipping. Nicely done)

 

Exchange rate

 

Duh of course! so US $ are diff to Canada $ lol, I'll play the "limey card" on that one k-moe

 

The exchange rate is a given, but the bit that burns my arse is the tenfold increase for shipping. I may just do the same thing as before and plan a road trip to make purchases. I'm only about an hour and a half (less on a bike ) from Port Huron so a bit of ME time on the bike combined with cheaper prices, plus the shipping alone would more than cover the cost of fuel and maybe McDonalds. A win-win all 'round!

 

I did the switch mod and it does kick in the fan just past the mid mark on the temp gauge.

However, the new switch was reluctant to shut the fan off until it reached the middle of the cold area on the gauge. Then it came back on just before it reached the middle (white) mark as the temp creeped back up.

Keep in mind that it's 35 degrees today (and snowing?) and at that point the fan just kept running while I had it idling? So I decided to let the bike cool down and than tested again. Did about the same thing. I suppose that I may have a switch that has a wider temp range for the ON/OFF switching.

So I did a little more research to see if there were any other options, and I found another switch that requires no mods. It has the same temp range as the SW537, which is ON at 203 and OFF at 194 Fahrenheit (95/90 Celsius).
For reference, the original switch has a range of 221 and 208 (105/98)

The Wells # is SW519 and I found it available through the local AutoZone.
http://www.autozone.com/autozone/parts/ ... fier=45306

Hope this helps anyone interested in doing this mod, and may save you guys north of the border a few bucks.

Tony

 

I also wanted to mention that the O-ring that came on the new switch was too large for our application. You will need to swap over your original one, or better yet, use a smaller and thinner new one.

The picture shows the original switch and O-ring on the left and the New switch on the right with the "Manly" sized O-ring that's too large.

 

Wow! Nice find; the SW519 looks nice and stubby, that will make reinstalling the thermostat housing a snap. The bulky SW537 made reassembly like solving a Chinese ring puzzle. Not having to make any modifications is a bonus too.

Another chapter in the quest for cool 8) . I've also wondered if it's getting too cool; but I keep going back to the statement in the owner's manual "...if the needle points to the red zone or higher, stop your motorcycle and let the engine cool..." Before the mod, the needle routinely 'pointed to the red' which couldn't have been good. That being said, we are guinea pigs here; so watch things closely and please continue post any observations.

 

As you can see in the previous picture, I had trimmed the lead wires back and unsoldered the wires. Made the install a bit easier, as the two connectors on the original jumper harness went right on to the switch terminals.

I actually swapped the switch over without removing the thermostat housing, saving some time there as well.

My biggest concern is not having the engine run cooler than before, that has to be a big plus for longevity. But having the fan running while idling in traffic draining the battery. We'll just have to make sure the battery and charging systems are operating at peak efficiency.

 

Good point. Leave it to me to not think through all the unintended consequences. I'm going to keep running like this and see how it goes; especially this summer when we get consecutive weeks at 95+. Nice thing is that the mod is not permanent and one could always go back to the stock setup. No such thing as a free lunch; nearly overheating engine OR tacky manual switch OR battery drain risk OR ...

**************************

Nice work on doing the change out without removing the thermostat housing! I couldn't seem to get the right angle and was afraid I'd strip it.

 

I have been following this thread since it started and I just remembered something that may impact the running temps of these bikes, and probably others, is how clean the rad is inside. I removed the plastic drain plug and was surprised to see how much crud had acumlated in the bottom part of the rad. I could actually see that a few of the bottom flow holes were plugged as I was getting concerned about how hot it was getting. I think it's because these rads are unlike a cars radiator that it's easy to "Not see it, so don't worry about it". So next time you flush the system it might be worth having a look.
Just a thought.

 

That o-ring in the pic looks just plain too big for the switch anyway, looks like it'd squash out the side in whatever application it was used in. maybe the wrong one was put in with the switch?

 

It was a pretty nice day today (52 degrees, partly cloudy, no wind) so I tried an experiment. I took the bike out for about 30 minutes and had it nice and warmed up, then took it into the garage and let it idle. The fan comes on just a smidge past 12:00 high and runs for about 1 min 15 sec before shutting off. It stays off for about 2 min 10 sec and then repeats the cycle. I did this with a stopwatch for a few cycles and it was pretty consistent. ~ 1min on ... ~2min off.... repeat. When I was riding, I looked down a couple of times while at a light and the fan was off. I never timed the intervals with the stock switch, so I can't compare directly; but it doesn't appear that I'm getting the "fan always running" issue.

Maxim-X makes an excellent point regarding radiator cleanliness. Because I pulled the thermostat housing to swap the switch, I had drained and flushed the radiator. It definitely spewed out a lot of gunk, pretty brown actually. Considering the bike is 28 years old and the service manual says to flush the radiator every 24 months, it's no surprise that a flush was badly needed.

 

Yeah Pickax, I honestly think I got a bum switch. I'm waiting for the weather to get back up to normal temps and I'll report after I do my testing.

When I did the bike over last year I had the radiator off and flushed it out with a hose. Lots of gunk came out, so I think that it's working efficiently now.

As Bloke noted, the O-ring that they installed was probably not the correct one for the switch. I just wanted to point out the need to have a properly sized one in place before installing the switch.

 

Ive decided to finally do this. Hows it going for you that have? Did we decide the sw519 is the best candidate?

 

The SW519 looks to be a better geometric fit for sure. The setpoints for the SW537 (what I installed) and the SW519 are different; as shown in the following specs:

SW537 Cooling Fan Switch
Normally Open, Closes at 193°F-205°F, Opens at 184°F, M16 x 1.5 Thd., 2 Male Blade Terminals

SW519 Cooling Fan Switch
Normally Open, Closes at 194ºF-212ºF, Opens at 185°F-203°F, M16 x 1.5 Metric Thd, 2 Male Blade Terminals

The SW519 Open/Close ranges overlap; the SW537 do not. I have no idea how these setpoint differences will effect things; I didn't look into these details when I made the mod; I simply followed a recommendation I found in the VMAX forum.

Today was a great day for another test; it was 97 degrees! I rode for 25 miles and then parked in the sun while idling. The fan kicked on; but unlike earlier this spring (see previous test above); it stayed on and held the temp just past 12 oclock (I took a pic). I then rode up and down the block at 35 mph for a bit, stopped and checked the fan; it was off and stayed off for about 45 seconds and then kicked on and held the temp steady as before. So I conclude that in very hot weather, with my SW537 at least, the fan is primarily off while moving but will run constantly if it comes on while idling. I'm OK with this.

 

Here's a warm weather follow up.

The SW519 switches the fan on before the temp gets too high, and will switch it off (when moving at speed) just to the left of the center mark on the gauge.

However, if you are not moving, the fan will continue to run after it switches on. It seems that the fan alone is not cooling it down enough to bring the temp to the point where it will switch it off. Not really an issue if you have a properly working battery and charging system. Keeping that in mind, it would be wise to bring the rpms up if you're sitting still for some time.

I'm very happy with the mod, as it keeps the temp from getting anywhere near the Red Zone before switching the fan on.

Tony

 

For the 1 or 2 people still following this; here's a "medium" weather follow-up:

67 degrees outside. With the SW537 switch installed, the fan is cooling the engine enough for the switch to trigger the fan to shut down after a minute or so at idle.

So far, the only 'constant running fan' situation for me has been in the >90 degrees outside temp range.

 

Still following, thanks for the update.

 

Still following. Wanting to do it for the vmax as well.

 

I'm happy with the SW519 that I installed. However, it is reluctant to shut off when sitting still with the engine running/fan on while hot. You just need to keep that in mind and keep the RPM's up so it doesn't drain the battery. Once moving though, it shuts right off and then it will cycle back on if the temp rises again.

The switch is available through local auto parts stores:

http://shop.advanceautoparts.com/webapp ... Assigned=1

http://www.autozone.com/autozone/parts/ ... umber=true

 

as I mentioned, studying the vmax forums is what inspired me to do this for the X. Here is the link that started it all

http://www.vmaxoutlaw.com/merchandise/performance.htm

$64.95 for the "kit" was a bit steep for me; which ultimately led me to the SW537.

 

They say on their website:

"Each unit temperature tested to ensure correct temperature operating range for the Vmax (we found this necessary due to tolerance and temperature range differences seen in different manufacturers switches)."

The one I installed is from the same company they use (Wells). But I wonder why it needs to have a low temp before it will cycle the fan back off? I suppose it's possible that mine's out of the tolerance range, as I never checked it in boiling oil to test it. Maybe one day I'll try another SW519 to see if it makes any difference.

All I know is that it sure is better not to have the temp gauge near the red zone before the stock switch cycles the fan on.

 

Amen Brother. It is smoking hot out here in the desert:
Today Jul 11 Sunny 99°
Sat Jul 12 Sunny 105°
Sun Jul 13 Partly Cloudy 108°
Mon Jul 14 Partly Cloudy 106°
Tue Jul 15 Sunny 106°
Wed Jul 16 Sunny 108°
Thu Jul 17 Sunny 107°
Fri Jul 18 Sunny 101°

I've been riding a lot in this weather with the switch mod and the X is staying cool; and looking cool 8)

 

Glad to see it's keeping the bike's temp under control. Been working great on mine, but we don't see near the high ambient temps you've been getting.

Only seen 90F or so here a couple of days thus far in the North East. Not nearly as hot as it usually is.

Just don't let it sit and idle for too long with the fan running and draining the battery.