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Electrical problems

Posted: Tue May 14, 2019 3:31 pm
by Dee555
So I have gotten started on tearing down a GL1200A I recently purchased to build a cafe racer. After removing the fairing I started in on the wireing and the deeper I’m getting into it the more of a rats nest it is becoming I think the previous owner may of been a (self taught) electrician. I’m now thinking about removing all the electrical from the bike and starting from scratch . Does anybody have any tips or any threads that already exist. I’ve also seen that some of the guys on here have used dodge neon coils. I was wondering if there are any updates on that because the post I saw were from 2010. I’d really appreciate the input and I’ll keep you all updated on the build.

Re: Electrical problems

Posted: Tue May 14, 2019 3:43 pm
by Dee555
Here is the start

Re: Electrical problems

Posted: Wed May 15, 2019 7:35 am
by Whiskerfish
I have read numerous posts about rewiring these bikes and I have done pieces and parts of it but not a complete job. I know some here have. It is a pretty big job and not to be undertaken lightly. If you can work with the existing harness you will be far ahead in the long run. tlbranth has probably the most thorough documentation of his on the "General Patton" thread but it ios a 1000. Look here https://www.ngwclub.com/forum/viewtopic ... 62#p718462

Re: Electrical problems

Posted: Wed May 15, 2019 6:39 pm
by Easter
The wiring of the 1200 Bikes is far more complicated than the earlier ones. (And much less complicated than the 1500 and 1800) I did a 1200 Interstate about a year ago and it was a real challenge. Fortunately I was able to get the bike started after removing all the Tuperware and just carefully and followed the wiring diagram and removed what I obviously no longer needed, then by trial and error gradually thinned out and or shortened up much of the rest. It is helpful to strip most or all of the tape wrapping from the harness in order to track the wiring colors and it also makes it much easier to relocate the wiring if you go to a shelter from an earlier year. Starting over from scratch is an option but the electronic ignition module and some of the relays such as fuel pump frightened me away.

Re: Electrical problems

Posted: Wed May 15, 2019 6:53 pm
by CYBORG
Easter wrote:The wiring of the 1200 Bikes is far more complicated than the earlier ones. (And much less complicated than the 1500 and 1800) I did a 1200 Interstate about a year ago and it was a real challenge. Fortunately I was able to get the bike started after removing all the Tuperware and just carefully and followed the wiring diagram and removed what I obviously no longer needed, then by trial and error gradually thinned out and or shortened up much of the rest. It is helpful to strip most or all of the tape wrapping from the harness in order to track the wiring colors and it also makes it much easier to relocate the wiring if you go to a shelter from an earlier year. Starting over from scratch is an option but the electronic ignition module and some of the relays such as fuel pump frightened me away.
I've done a 78, and a 85 1200. Not to bad if you know what your doing. But can see how it could be a problem if you don't

Re: Electrical problems

Posted: Wed May 15, 2019 10:03 pm
by Dee555
After doing some research I think I’m going to pull the complete harness and start fresh. I’ve been looking at some wire diagrams for cafe racers and I think I’ll be better off with a fresh slate making use of a few of the existing components. I know these diagrams miss a few things like the fuel pump and the fan but I’m going to try to use it as a base and will probably draw up my own diagram as I put everything together. I’ll try to upload it later on for anybody that is interested. Here is a video that helped me https://youtu.be/GzI9UN2nOyk

Re: Electrical problems

Posted: Thu May 16, 2019 11:38 am
by Oldmopars
I am also working on the twin to your bike, color and everything. The biggest issue I have run into with the wiring is the stupid digital dash. I found that it was just a complex mess. I one wire at a time stripped out the dash leaving just the indicator lights. I will then just use a standard speedo from another bike. I plan to keep it simple, I never really use a tach, don't need a lot of extra fluff. I only want to add back the gas gauge and temp gauge. If I can monitor my speed, temp and gas I will be very happy.
From there I am working on the lights. These Aspencades are a royal pain. I have one connector from the bike to the fairing that nothing is connected to, and I have a fully running bike. There are at least 20 wires going to a plug with nothing connected. That will take a while.
I agree with the other here, open up the harness and one wire at a time remove what you do not need. If you start with a running bike, then clip a few wires you don't think you need, then start the bike back up and test everything you will know that you can safely remove them. Repeat this process. If you clip a wire and it won't start or the lights won't work, you can connect it back up and start again. Just go slow and only do a few wires at a time. It is easier to go back then if you strip out 50 wires and then have no way to know what you screwed up.