DOHC re-wire

[willem]

Hi everyone,

Since my slightly neglected DOHC has some trouble with its electrics (see below), I'm looking to do a re-wire of the signal- and lighting part of the electrics. As I'm working out what wires to get from the manual, I'm coming across a few things I need some pointers with.

In the manual it says there is a "meter light". It's connected to the light switch as well as the main switch. Is this the light in my dash that's supposed to help me read the tacho- and speedometer when it's dark? The dashboard light? My bulky dash has been replaced by a small speedo and neutral/oil light, so I can't check what wire is connected right now. Doesn't look like I even have a dashboard light.

Also, is there anyone who has done a rewiring of a DOHC lately and has something he/she can share, like an overview of wire colors, thicknesses and especially lengths needed, or any other pointers? I'm making a list of my own, but it would be nice to compare. Of course I've checked out Drewpy's rewire how-to, but the DOHC is a little different I believe.

I'll be soldering the connections and using shrink tubes, of course. I would like to stick to original colors so if anything has to be replaced in the future its clear what's what. Just have to find a shop where I can get all the right wires in the right colors, by the foot/meter.

If anyone is interested, I can try to report my progress here as well along with some pictures.

Not working right now are:
- brake lights
- one of the double aftermarket tail lights
- other one of the two works only sometimes
- main switch (key switch) unstable
- flasher relais needs to be replaced by LED relais (aftermarket LED rear flashers are installed)
- flasher cancelling unit

 

[bcware]

Before rewiring have you...

Checked the bulbs to see if they are bad?
Replaced all of the fuses?
Checked the fuse terminals for continuity?
Inspected all of the pigtails for corrosion where the connections are made?
Inspected the harness for signs of damage or previous modification (electrical tape)?

 

[16VGTIDave]

I'm with BC. A re-wire probably won't fix many of the issues listed. I'd suggest starting with rebuilding the ignition switch. All the power for the bike goes through it, except for the starter, so it is critical to correct operation of the electrical system.

It will take 2 -3 hours to remove, clean, and rebuild the ignition switch. And while the headlight is dis-assembled all of the connectors inside can be cleaned. After this has been accomplished, any remaining faults can be addressed.

 

[willem]

Before rewiring have you...

Checked the bulbs to see if they are bad?
Replaced all of the fuses?
Checked the fuse terminals for continuity?
Inspected all of the pigtails for corrosion where the connections are made?
Inspected the harness for signs of damage or previous modification (electrical tape)?

I've been looking through the wiring quite a few times to find fixes to my specific problems. Fuses are all still fine. Almost all connectors are old and corroded to some extent, and POs have put aftermarket parts on (turn signals, taillights) so they have been previously modified. Looks like it has been done semi-decently, with shrink tubes but often wires with excessive lengths. But all together the wiring is quite old, most of it probably original. It's rusty all over, stiff and all plastic connectors have become brittle.
Pretty sure the one bulb in the tail light is shot, though. The other one works sometimes, so that's probably a shoddy connection issue.

Today my ignitor unit also gave problems, went as far as having to call road assistance (good thing I became a member, had a feeling this was going to happen at some point). Got it to run again with help of the mechanic, but now pressure is definitely on.

 

[willem]

I'm with BC. A re-wire probably won't fix many of the issues listed. I'd suggest starting with rebuilding the ignition switch. All the power for the bike goes through it, except for the starter, so it is critical to correct operation of the electrical system.

It will take 2 -3 hours to remove, clean, and rebuild the ignition switch. And while the headlight is dis-assembled all of the connectors inside can be cleaned. After this has been accomplished, any remaining faults can be addressed.

Thanks for the tip, I was also thinking about starting there but now definitely going to go try that first.

 

[bcware]

Did you actually replace the fuses or are you assuming they are good? I've had bulb fuses blow and appear to be fine. If there is any doubt replace them all.

Have you actually manually tested each light with an external battery? You need to do this first.

After the bulbs/leds are verified working I would simply trace the connection backwards testing for continuity along the way. A wiring diagram from the manual will come in handy.

I'd like more information about your aftermarket flasher relay. What kind is it?

Finally, did all of this stuff work and fail while you owned the motorcycle or did it never work since you've had it?

 

[willem]

I've checked the fuses for continuity, if they would be blown they wouldn't be continuous right? Maybe I should replace them all anyways.

The lights all work except for the left taillight. I haven't gotten around to testing that bulb. With the break lights not working I meant that the taillight doesnt get brighter anymore, this worked about a week ago. Probably due to something in the sensors, need to check that.

The horn never worked, neither did the flashers flash or cancel. I'm picking up my flasher LED relay from the shop on Tuesday morning, I'll let you know what kind it is. Should be just a current-independent 12V relay.

 

[ksqrly]

The rewire isnt as bad as it sounds, as long as you understand whats going on. The best thing to keep in mind when doing it, is the flow of electricity. As long as power is going to something and grounded correctly it will work(Im sure you know that though ha). Just take it one circuit at a time and its not bad.

 

[willem]

I've had a lil bit of help and now my horn and taillights work properly. The horn issue turned out to be a completely corroded and rusted switch and the taillight bulbs just weren't connecting well to their housing. Little bit of soldering made them as good as mc gyver-new. I'll do a rewire maybe some time in the future, but as it looks now it's not really needed.

As long as it's not broken, I ain't fixin it.

 

[ksqrly]

Good to hear you got everything in order