1981 XJ550 No horn, no signals, no brake light

Hi all .... had an '81 XJ11 and a '78 XS11 Standard. I recently bought an '81 XJ550 Cruiser complete with electrical gremlins. Coming up short with ideas on how to fix these issues.

What Works:
New Battery,
Starts,
Runs,
Headlight comes ON,
rear Running Lights ON
--------------------
NOT WORKING:
No Turn Signals,
No Brake Light,
No HORN
--------------------
Previous Owner had too large a battery case / terminals reversed from stock. + and - Cables are attached correct however, but POS cable is now a bit short. New OEM battery is on its way.

Was blowing Signal 10A FUSE (to Brown Wire), repaired short-to-ground in that wire, now 12V flowing okay. Just tested the HEAVY BROWN WIRE from the Ignition KEY and its carrying 11.6V to the Fuse panel.
Still No Turn Signals.

Replaced semi-ruined Ground Strap under Battery - (it got Hot when PO ran POS + wire along top frame rail = arc contact). MAIN 20A fuse saved the day.

Even with all 4 fuses intact with 12.4V, Cleaned turn signal Switch, tested good continuity thru both horn wires (Pink N Brown) still No Horn, No Signals. I hear one relay Click one time when KEY is ON.

BLUE WIRE to rear RUNNING LIGHTS has 12V, but No voltage to rear Brake Bulb side, nor to the rear BRAKE SWITCH.
----------------------------
Busy electrician down the street says most of these XJ's troubles seem to come from a bad Rectifier in-his-opinion.

ANY ideas? I have a Radio Shack Digital Multi-tester and a Self-powered Test Light.

Can anyone ID the XJ550 electrical items in the 2 pics?

 

Can anyone tell me exactly where the TURN SIGNAL RELAY is located? Neither Haynes nor Yamaha Handbook gives any clues. thanx, RJ

 

The 550 guys will jump in but, I don't think any of the XJ's have rear running lights.
This maybe a place to start.

 

It should be between the frame bars under the tank.
It is always a pain when you first get a bike with several electrical problems, I have had to strip the binding off the loom & test each wire individually. Test each bulb, off the bike & check they are the correct voltage & amps. Keep it simple and get one thing working at a time.

 

I've got two bone-stock 550 Secas and a factory service manual (including the Max supplement.) I can help you with this but it won't be until this evening (Thurs.) I can tell you that neither of my 550 Secas has running lights; can't say for sure about the Max but I suspect not.

 

Finally found the flasher relay buried right next to the coils (?) go figure.

Have a spare 3 prong Flasher Relay off an old XS bike - turns out it has the same specs and case as the XJ unit. Will give it a Go today & see if it works or not.

This '81 Maxim XJ550 H model (not a Seca) does indeed have daytime running lights with the 2 rear single elements burning bright all the time along with the headlight. I've switched the twin 2057s for 2 less stressful LED bulbs & the amp / current load dropped.

11/6/09 update
Tried old XS Flasher = NO GO ... so I'm re-testing the signals circuit to & from the handlebar switch along with 12V supply from fuse panel. Then its off to the Auto Supply for a brand new 3-Prong unit.

thanks for the tips, RJ

 

Just a heads up the LED's will draw less current.
but it is the current that heats the cancel relay to turn off turn signals.
So you will lose your cancel feature.

 

Thanks Hound - good info

Replaced old XJ Flasher Relay with a brand NEW Electronic 3-Prong 12V FLASHER RELAY.

Checked LH Bar Switch ... 9 wires. Soldered joints are sound.
All have good continuity & function from the 2 intermediate connectors (under tank) Up to and into the bar Switches. Left blade & Right blade of turn switch connect properly.

Though the Button has slight resistance it will Not sound the horn.

Brown signals wire from Fuse Panel carries 12V up to the Switch Harness connector.
Still No Horn & No Signals

Running outta time & patience ...
Now seems the right time to replace the entire Wire Harness 'cause there's a hidden fault inside the loom, e.g. 'somewhere'

 

Hey man, I had this exact same problem on my 82' XJ 650. I found the problem to be in my fuse box! I pulled all the terminals, cleaned them, replaced all the fuses with shiny new ones, and cleaned up the terminals, and it worked like a charm! I also noticed when it wasn't working, I could shake the fuse box, and the lights would flicker. Give the fuse box a shot, and see where that gets ya.

 

Sounds like a great idea... this afternoon's project.

Update: I did the Fuse Box cleaning steps to NO avail.
Still got them gremlins ...

 

It is a frequently recommended thing that you replace the old fuse panel on thes bikes to eliminate electrical problems that are or may in the future arise. That would be a good place to start.

 

If the original flasher is for the Yamaha self-cancelling setup, then an off-the-shelf 3-pin electronic flasher will not work.

Was the original a Nippon Denso unit? Perhaps labelled FU257CD?

I am in the process of writing up an LED conversion FAQ. Should have it finished tonight or tomorrow. Part of it describes how to convert to LED turn signals and integrate with the stock turn signal switches and cancelling system.

I'll post it over on the FAQ Suggestion forum when it's ready.

------------------------------------------------------

OK, it's ready: http://www.xjbikes.com/Forums/viewtopic ... tml#114964


Cheers,
Paul

 

Paul - I believe you are correct about the ND unit. Will go back to using the oem Flasher.

I'm obviously missing something in solving the Fuse box + Old wiring X Vibration = Gremlin equation.

So its time to strip down the loom and trace out & test every wire properly ... all the rest has been guesswork up to now. Somewhere there's a break / fault lurking ... never say die.

 

The closest schematics I have are from an XJ650H. On that bike the horn, brake light, and flashers (and instrument back lights) all get power through the "Signal" fuse.

I'd take a close look at that fuse and its clips, and make sure I'm actually getting 12V from ground on both sides of it.

Cheers,
Paul

 

Paul - I tested the Signals 10A fuse flow - with IGN KEY 'ON' it's getting 12.11V (holding negative probe to (-) Battery terminal) in both directions (spade left side v.s. right side).

Has a brand new 10A fuse; Signals fuse keeps blowing even though it's NOT indicating a short in that circuit. Using the oem ND Flasher.

 

td; Do you need a schematic? I have a factory 550 book with the Maxim supplement in it. PM me with your email address and I'll have my kid scan it for you.

 

Re: Blowing the Signals fuse

Does it blow that fuse all by itself with just the ignition on? Or does it blow after something else, like trying to enable the turn signal, press the brake lever, etc?

Do you have instrument backlight illumination before the fuse blows?

It may be better to leave the flasher module disconnected, so that you have one less sub-circuit to worry about while troubleshooting. Once you get the brake lights and horn working, you can put it back in and work out any remaining problems.

 

bigfitz - thanx; I have a weathered Yamaha schematic for '81 cruiser. Just working my way through the circuits ... bit by bit.

SQLGuy - Fuse blows after I attempt to enable the turn signals.
There is NO instrument illumination before the fuse blows.
Headlight comes on after the engine is running - then instruments light up.

I agree - signals fuse didn't blow with the oem ND flasher installed... pulling it anyway as you suggest. "One war at a time" A. Lincoln

 

Cool. I had my daughter scan the schematics as well as the cable routing and component location diagrams. If you need anything else just holler.

 

re: REAR BRAKE LIGHT TEST

SQLGuy - Just did a "buzzer" Ohms test on small brown wire to Rear Brake Light switch. KEY is OFF during this test. The buzzer tone is just barely audible and the meter scale reads 350-400 Ohms.
It seems that Brown wire has high resistance back to left side of Signals terminal in fuse box.

Did I do the test correctly – probing Brown brake wire running back to that terminal?

 

I'm not sure what you mean by "buzzer" test, but the resistance between the load-side of the Signals fuse (fuse removed) and the brake light switch should be less than 1 Ohm.

To narrow things down, you could make a jumper wire with an in-line fuse holder, put a 10A fuse in this, and then jumper +12V directly from the battery to one side or the other of the brake light switch. If you jumper to the "far" side, your brake light(s) should come on. If you jumper to the "near" side, they should come on when you press the brake. If you confirm that these are the cases, that isolates down to a problem between the switch and the Signals fuse. If not, then you have at least one problem between the switch and the lamps, and/or from the lamps to ground.

 

SQLGuy - I'd used my Analog Meter's continuity checker e.g. "buzzer" function to see if there's a complete circuit from Signals fuse to the brake switch wire but the results were mixed / inconclusive.

Voltage test from Battery (-) terminal to the load side (outboard / left fuse spade) of Signals has shown 12V present.

OK your test procedure with the jumper wire sounds simple & reliable;
> this will be Monday's project.

thanx again to you & all the members, for this important info.

 

Checking resistance is useful. Checking voltage may be less so. Reason is, if there is no load (brake lights not engaged, horn not sounding, etc), then, if there is a bad connection somewhere but the connection is not open, you'll still read 12V.

Also, if you check resistance from the Br/W wire of the turn signal flasher to ground, after switching the handlebar switch to one side or the other, you should read about 3 Ohms. After resetting the handlebar switch (pushing it in), you should read open.

Cheers,
Paul

 

10A fused Jumper from battery allowed rear brake lights to work fine using brake pedal. So the trouble is elsewhere.

Think I may have found the source of all the electric gremlins as I unwrapped the harness.

There's a WHITE TAG tag wrapped around the harness under the seat.
In red letters it reads "CHECK UP - Pacific Enterprise Ltd"

It appears this was a warranty repair at some point in the bike's past. However the 3 B / R / R/Y wires from the Ignition Switch seem to be spliced together instead of each having a clear path as shown in the schematic. All Blue wires were spliced adjacent to the relays.
Wrap is not Yamaha style.

SEE PICS

Rather than unscrambling such a huge mess I've decided to install a used wire harness (keeping fingers crossed).

 

I suspect Pacific Enterprise Ltd. isn't a Yamaha dealer and that doesn't look like a "warranty" repair to me; looks like a very professional HACK JOB. Swapping harnesses sounds like a winner from here!

 

Interesting. I can't think of a reason for that to be done in the first place. Who knows what else has been "repaired"

 

This is a fine example of a "pseudo" harness, one made to look & feel exactly like the real thing. I suspect this company obtained junked looms and rebuilt a batch and then sold them to unsuspecting owners, used bike dealers, repair shops etc.

 

That makes sense. Just make it appear electrically correct. Be hard to know that you had one unless you tear apart as you wound up having to do.

At least you have the knowledge to resolve the issue.