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Replace Turn Signal Relay - '78 R100/7

20774

Liaison
Staff member
Well I guess it's that time.

- Symptom -- the signals don't flash...if they do, it's like once every 30-60 seconds
- Consequence -- last year at this time I was graciously given a pass on my annual inspection, provided I get it fixed.
- Result -- it's been nearly a year and the inspection is due...again :banghead

So, find the part. For my bike it's 61-31-1-358-194. This is the relay for /6 models through bikes built in 9/80. Of course, I have the Luftmeister fairing, plus I have a number of wires (besides the fairing umbilical) that feed through a small hole in the bottom of the fairing. These wires are 1) voltmeter with direct feed from battery positive terminal...not reading what's at the headlight circuit board which can be around 0.5v low; 2) fairing clock; 3) a master power feeding a switch on the inside of the fairing which lets me turn off the voltmeter and also has power applied to an Autocomm system when in use; and 4) a good frame ground for the instruments.

Tank off just for the heck of it. Fairing comes off and the headlight rubber dust cover is removed. First picture...things look pretty clean inside here given that the cover is sealed all the way around with electrical tape. The second picture shows the relay removed from the holder on the left side. The last picture shows a comparison of the working end of the old relay on the left and the new one on the right. When removing the old one, I felt some looseness in the housing. Notice the whitish dust on the left relay. Apparently, the cover had worked a bit loose and was chafing. I don't think these are hermetically sealed, but that wasn't good.

While in there, I took both fuses out and roughed up the ends for better contact. One of the fuses was a little mangled so I replaced it with a spare that I had. Plus tried to move around most of the connectors that I could easily get to hopefully to help break any corrosion that might be setting up.

New relay in place (with dielectric on the spades) and unfortunately, I really had to put the fairing back on and re-feed the wires into the fairing. Then the smoke-test. :eek Everything works fine. The signals click back and forth as fast as people exiting the D-train in downtown Manhattan. :thumb

Noted for the future:

- red flakes in the petcock screens :( that's going to happen sooner or later
- brake fluid needs a change...the fluid on hand is an open container and over 4-1/2 years old :( :(
 

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74 R 90, front turn signals always were weak, sometimes not working, knew it was a bad ground through the stalks to the yoke. So recently wired in direct ground wire from bulb holder post to yoke bolt. Now bright and steady. Still running with forty year old relay. Don't know how your's are grounded.
 

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My relay is ground through the system wiring, which is terminal 31 on the relay which ties into terminal 31 on the headlight shell board.
 
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