My second project: 83' 635CSi

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My second project: 83' 635CSi

Post by stormhunt »

Hello everybody,

First of all I wanted to thank you for accepting me in this community and I hope to accumulate (and share) as much knowledge as I can about these beautiful machines and I think this is the best place to do so. This is my first ever post on a forum so please forgive me if some of the things that I say are not 100% coherent

I just purchased my second historical vehicle, a 635 EU spec. I am currently 2 weeks in on reading forums and documenting myself on this model ( I have some previous experience rebuilding an E21 with an M10) and found out that even though they are similar in terms of engine architecture, the E24 is a whole other ball game to the E21 and to be honest i am a bit overwhelmed :oops:

To give you some headlines on the state of the car:
-Engine: Runs smooth and has no leaks (never seen a drier engine on any BMW that I owned so far :mrgreen: )
-Transmission: Shifts as smooth as you can expect from it
-Bodywork is in good shape, some surface rust here and there but nothing to write home about
-Paint: ok
-Interior: ok
-Electrics: Bad IMO (to be fair I might just be scared of the number of things that don't work)

I am currently in the planning stage of the build since I want to do my homework and be as thorough as I can with the overhaul of this car. So far I only managed to do some basic things such as doing an engine flush, replacing all the fluids and ordering some parts for a brake caliper rebuild as well as batteries for the SI controller.

The task that scares me the most, so to say, is the electrics since I have no prior experience with this kind of work. Any input in this direction is welcome. To give you a list of what doesn't work that I noticed so far:
-Front and rear fog lights
-Odometer and trip meter
-Fuel economy gauge
-Water temperature gauge
-Right rear window works only halfway
-Left rear doesn't work at all
-Dash lights flicker intermittently
-The tachometer jumps up and down when the headlights are turned on
-I am missing the wiring for the light under the hood and trunk

I wanted to get some input from you guys on how would you tackle this project all things considered. I'm not sure if this is the right topic to post this in but it is the best one I could think of since I also wanted to keep track of the evolution of the car.
Thanks in advance
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Re: My second project: 83' 635CSi

Post by hornhospital »


This should help with your electricals/electronics: ... Manual.pdf

Download and save that. It is the Electronic Troubleshooting Manual for a 1983 633. The electrical system should be similar enough to be helpful on your 635.

Every symptom you list concerning the instrument cluster weirdness points to grounding problems.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann";'87 325is "Odette"; '93 325is "Elvira"; '95 M3 "Ashlyn"; '95 318is "Bebe"
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Re: My second project: 83' 635CSi

Post by 87Shark »

Welcome to the forum! This is THE PLACE where you will find almost all the info that you will need to help guide you down the rabbit hole that we all know and love! Good luck and load some pics!
'87 L6, Arctic White
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Re: My second project: 83' 635CSi

Post by stormhunt »


Thanks for the replies,

I am planning on redoing all the grounds since the gremlins aren't getting any better and I will recondition the starter motor just to be safe.
I'll keep you updated on the progress

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Re: My second project: 83' 635CSi

Post by 86_6series »

When you rebuild the starter, don't forget to do the solenoid.
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Re: My second project: 83' 635CSi

Post by RossDinan6 »

Do download the ETM posted earlier. There is no guessing with electrical repairs. Also, clean up the grounds as also mentioned above. Even if not an issue it is worth the effort to eliminate the possibility. It sounds, by your list, that you have some instrument cluster issues.

Since you expressed concern regarding electrical work;

You will need to have a decent multimeter and at least some proficiency with it. Being able to measure voltage, resistance and continuity with it are necessary. While You tube is not my first go to source for information, I have no doubt there are some good basic electrical tutorials there. Also, learn to read the ETM. There are some basics regarding reading the schematics in the front of the book.

And last, start troubleshooting and post your questions. There is a pretty deep knowledge base here. My tattered ETM is always close at hand.

Best of luck.
'84 633 Dinan turbo
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