1978 98 regency diesel electrical problems

[KRICHEN922]

Speedometer lights were operational a few days ago, now shot.
Dome light and reading lights inoperable
Courtesy door lights inoperable (possible water damage)
Door locks worked now inoperable (possible water damage)
Window motors failing (possible water damage)
Car radio illuminates, nothing else (Optimus circa 1998)

Original electric clock (non digital) covered up for some reason
License plate lights- 1 not functioning

All I can think of at the moment. Any ideas as to why (there was a rat infestation) these are so or (most appreciated) trouble-shooting schemes I could follow. Thanks for your help.

[joe_padavano]

Originally Posted by KRICHEN922

All I can think of at the moment. Any ideas as to why (there was a rat infestation) these are so or (most appreciated) trouble-shooting schemes I could follow. Thanks for your help.

Given your multiple posts, the first thing you need to get is a Chassis Service Manual for your car. Spend the money and get a factory book, not a Haynes or Chilton.

[KRICHEN922]

I do have one but it is not the original engine o=nor, i suspect the original wiring. The manuals aren't really helping me

[lshlsh2]

check fuses. after that start opening things up and tracing wires. Rats and water sounds like you might be rebuilding a wire harness. I don't know if anyone sells a replacement harness.
OH RATS!

good luck Larry

[KRICHEN922]

Ha, I get the basic principle of what you are saying but have no idea how to do it without me irreversibly breaking something.

[joe_padavano]

Originally Posted by KRICHEN922

I do have one but it is not the original engine o=nor, i suspect the original wiring. The manuals aren't really helping me

The originality of the engine should not be related in any way to lights or other wiring unless the installer was a complete idiot.

Originally Posted by KRICHEN922

Ha, I get the basic principle of what you are saying but have no idea how to do it without me irreversibly breaking something.

In that case run, don't walk, to your local community college and enroll in a basic auto electrical course.

[KRICHEN922]

You didn't understand me. THe MANUALS would not help me because the WIRING and ENGINE are not the ORIGINALS

[KRICHEN922]

I'm still in high school, so I am just taking a shop class next year... already had that planned...

[joe_padavano]

Originally Posted by KRICHEN922

You didn't understand me. THe MANUALS would not help me because the WIRING and ENGINE are not the ORIGINALS

You didn't understand me.

Once again, the problems you describe with lighting, etc. are COMPLETELY UNRELATED to the engine being original or not. Are you saying that someone has completely removed the original wiring harness and done something custom? In any case, the Chassis Service Manual will tell you how each circuit is SUPPOSED to be wired.

[Olds64]

As stated, check your fuses. Make sure all of the fuses and relays are in good condition.

Speedometer lights were operational a few days ago, now shot

If it isn't a fuse I suggest using the instructions in your FSM to disassemble the dash. Once you have the lower part of the dash off you can probably reach behind the insturment cluster and remove the bulb from the speedometer. Check it to see if it is blown. If not, you have to do some diagnostics with a DVOM (digital volt, ohm meter).

Dome light and reading lights inoperable

After checking fuses check the bulbs. Your FSM should tell you how to access the bulbs. IF they're bad replace them, if not you might check the switches in the door. These are high wear items and go bad or get out of adjustment easily.

Courtesy door lights inoperable (possible water damage)
Door locks worked now inoperable (possible water damage)
Window motors failing (possible water damage)

If you have water damage in your doors the best thing to do is completely disassemble them and thoroughly clean the contacts and connectors in anything electrical.

Car radio illuminates, nothing else (Optimus circa 1998)

Remove the radio and run 12 V to it and a speaker to it. See if it works. If it doesn't buy a new one.

Original electric clock (non digital)

These always go bad, the only way to fix them is to put a retrofit kit into them or have them rebuilt professionally.

License plate lights- 1 not functioning

If only one bulb is working then replace the bulb that is bad.

[KRICHEN922]

Speedometer works now. I somehow fixed them now.... but no idea how. I working on the other stuff currently

[70 cutlass s]

Sounds like you had a bare wire making contact with metal grounding it out. Check for bare wires need to tape them or replace them.

[KRICHEN922]

Ok. I'll check it over when I got time. I plan to do a lot of this at once when I redo the interior and have a lot of stuff out of my way.
Currently school and my activities are preventing me from getting much done.

[a6m5zerosen]

I have an '85 Custom Cruiser that had similar problems (including the rats). I found a big ground wire badly corroded on the inside of the firewall. It was just behind the top edge of the passenger footwell carpeting roughly under the glovebox. I took it apart, cleaned everything up with a wire brush, put it back together & it worked like a champ.

[henryk8398]

I don't have any issues with the dash lights, but I DID have inop dome and courtesy lamps. My power door locks didn't work either. On my 83 regency, that is all one circuit protected by the same fuse. I removed the door panel and the flexible conduit that goes between the driver's door and frame. There was an orange and white wire that was shorted to the door in two places. I cut out the bad parts and rerouted it. No more problems!

[KRICHEN922]

Thanks for all the help guys... but a bigger problem has popped up. Homework has had me bogged down but this is a problem: Headgasket blown, cracked head unit, and cracked pan. Don't know what/where most of these things are but obviously, this takes priority over electrical and interior problems. I am creating a new topic to discuss this new problem.