'82 750 MAXIM-BATTERY WARNING LIGHT

Hello- New member and beginning rider here.
I just bought an '82 750 Maxim and the battery warning light won't clear and stays on.
The bike runs great otherwise, but this warning light concerns me.
Can anyone give me any ideas?
Thanks

 

First, welcome to the forums!

Your battery is probably fine. the original batteries on this bike (which i don't think they are making anymore) came with sensors in one of the cells to measure the battery's condition. The sensor sent a voltage to the computer to tell it that the battery was ok. unless i'm mistaken, it looks to see weather it has voltage or not (1-14ish VDC = warning light off, below that = warning light on). if you have a newer battery without this sensor, the warning light will flash and the battery indicator on your LCD display will light.

There are a couple ways to fix this...

1) Buy a battery for your bike that comes with the sensor (i've been able to find them on e-bay every once in a while)

2) (much cheaper) wire the sensor wire (that would go into the battery) to any voltage source you can find nearby. People have wired a 2.2kohm resistor in series with this to bring the voltage down to 5 volts but i don't think it's necessary. the 12(ish) volts you get from the battery should shut that warning light off.

Hope this helps!

Good luck!

 

Hi, I have studied this on my 3 750's. I have found if the battery sensor is in good shape it only is only senseing the acid in the cell its in. It picks up a small amount of voltage that sends a signal back to to module in your status display.( its really a low battery water warning light ) If you take a volt meter and test from the sensor wire to ground it should be 4 to 6 volts. Now if that it what you are getting and the light is still blinking and won't clear here is where you look next. The wire is white and has a red tracer on it (red stripe) that goes under the tank into the headlight. There is a connector in there that that wire goes through. Test your voltage there. If you have it the wire then goes through a set of contacts in the ignition switch. That is where my problem was. I took the ignition switch apart and cleaned the contacts with steel wool and put alittle white grease on the contacts and it works great. Some people like to just connect the battery sensor wire to the positive on the starter solenoid but I think that if there was to be a problem with a bad battery or if you were trying to jump start the bike it could blow the electronics in your speedo. Hope this helps, & good luck

 

True, my 2 ways to fix the problem were assuming you didn't have the battery with the sensor. If you do have it, you need to trace out the problem as described above.

 

Thanks for the answers-
The battery is new with no sensor so that's the source of the battery alarm.
I'll try out Bluepotpie's remedy.

 

The sensors are still available from Yamaha if you are interested.

You can find the part number @ www.starmotorcycles.com Go to Parts and check out the pictures under the electrical section for that bike.

 

Thanks MN- I'll definitely be checking that out.

 

that's good to know. the parts guy at my local dealer said they weren't and to take a piece of electrical tape and cover the warning light to fix it. needless to say, i wasn't happy with his answer.

 

Just as a note: If you happen to order a new battery sensor from Yamaha, Two things you need to be aware of. The new sensor is threaded, If your battery has screw caps your alright, if it has push in plugs , take a tap and make threads in the battery. The second is you will need to check the depth of the cell you are going to install the sensor, since battery companys do not make their batteries all the same you may have to cut the sensor off alittle so it will not screw into the plates. I junked one of my batteries doing that. Its alittle work but you can get your battery light to work like it was meant to. Good Luck

 

I have eliminated that pesky battery warning thanks to the sound advice on this site.
I also eliminated the brake warning light when hitting bumps by cleaning the crap off the magnet inside the float(more sound advice from this forum).
I have a haynes repair manual on the way and with that and all the know how on tap here I am ready to tackle things with confidence.
Next project-oil and filter change and rear drum replacement.
Once again- thanks a bunch!

 

I second that. You guys saved me a lot of time and hassle with this information. Thank you !

 

Try one of these on for size. Got ahold of one from Chacal, and I don't have the dreaded BATT staring me in the face when I'm riding anymore.

 

Thanks for the tip - Sounds more useful than just disabling the sensor/warning all together.

 

Most all battery's are sealed now so what is the best way to turn off the warning light. yamaha xj750 maxim.

Thanks

 

We offer2 solutions: a sensor bypass wire, or, a low-VOLTAGE (rather than a low-WATER LEVEL) harness that will solve the issue.

The third solution is to remove the bulb behind the battery warning light (requires cluster dis-assembly) .

A fourth solutio nis to just keep pushing the "reset" button on the cluster to silence the warning light.

 

Thanks, I found the PDF on this.

 

johnzapf, Where did you find the pdf? I have a 1983 XJ750 Maxim. Thanks.

 

I don't think the 83 Maxim had a "BATT" indicator or CMS monitor, but here is the link you are looking for along with some others

http://xj4ever.com/downloads.html