89 Cadillac wiring Schematics

[BirdieMod]

89 Deville FWD 4.5 V8. The Chiltons book sucks, Diagrams are very incomplete.
Gave the car to the future stepson but something popped up intermittantly draining the battery. I have it traced down to the body control computer/seatbelt circuit I think as that circuit in the BCC module keeps burning up. Sick of replacing that darn 152 buck computer.
Thanks

[lefty]

The Chiltons book sucks, Diagrams are very incomplete.

PM sent just a moment ago.

Hope it helps you.

[BirdieMod]

Pm'd back. The link didn't work for me here.
Thanks though for reading this and taking the time Lefty

[ghost71799]

Hey Birdman try your DVOM, or digital volt ohm meter, turn it to volts DC, make sure to turn the ignition switch to off and hook up the volt meter to your negative battery cable that means volt meter red lead to ground on battery and black lead to firewall and have your son pull fuses and put them back until the drain or load goes away "note" that there is a drain for computer memory and radio clock, but should'nt be over a 0.5 volts DC excessive drain is above a volt.

Which ever fuse it is, look at the wiring diagram to see what all runs on that circuit and begin checking parts with your DVOM that should narrow it down to one thing so you can replace it.

ghost

[#40Fan]

I could give you the wire diagrams that I have from AllData, but I bet they are the same as what is in Chilton's. GM's diagrams flat out used to suck back in the days.

[Ohms]

Mr. Bean has it right. That's the way to find a current drain. I should mention that you need to disconnet that neg bat cable, and connect the meter between the battery post and the disconnected cable. This will let the meter show the volts flowing. then pull the fuses one at a time looking for a drop in voltage on the meter.
At least that's the way we did it some 25 years ago when I was a wrench turner. :)

[ghost71799]

By the way Ohms, "that was a tech question on engines 1 test," to tell you the truth, I would rather blow shit up, or learn more about the flow of netrons and electrons.

ghost

[Ohms]

Nice to see old school still works on some things. That's probably the only question I would have gotten right.

I'm with you. blowing shit up has always been fun.

[BirdieMod]

Tried all the fuses and none were it, It pulses like a circuit breaker popping in and out. These cars though have 3 separate fuse/relay and circuit breaker panels so with this much wiring it makes the tracing somewhat difficult without a diagram.This one was a series 60 prototype fleetwood deville fwd so the darn thing has every option just adding even more to the wiring in it. The schematics so far seem all to be third party and lucky if they have been complete enough to even show plug wires LOL.
Thanks all though, Will get it figured out yet.
Oh, Have been monitoring it using a Ammeter for draw, Voltmeter no help.

[lifted_99]

yeah.... setting the meter to volts will not really show you want you want to see.... you need to keep the ammeter going birdie... what you are looking for is about 250ma draw maximum... most excessive current draws are from aftermarket equipment and/or wiring modifications... i have mitchell here at the house.. i'll pm you the power distribution circuits...

[BirdieMod]

It does a 20 amp draw for about 15 seconds then nothing for about 1.5 to 2 minutes then repeats still makes me think a circuit fused with a breaker I haven't found, Pulled the 2 breakers in the main fuse box and those were not it . Key off and doors trunk etc all closed. No aftermarket stuff installed, All original. It does have the Bose sound system and one of the amps is not working, But disconnected that and no difference. One by one disconnected almost everything under the hood and still does it's little power draw cycle, Also pulled every fuse in the main box and same thing so ruled all those circuits out. It does have a hidden panel by the passengers feet under the glove box and actually starting to smell something burning around that area, Not good. The seatbelt dinger in the body control computer behind the glove box is starting to sound pretty sick so think thats the area to look into.

[Texas Trophy]

Hey Birdie, have you got that thing figured out yet? I have a wiring diagram from ShopKey5 aka Mitchell On Demand if you want it. I'll have to fax it to you, so let me know.

[lifted_99]

here you go

[BirdieMod]

Thank you, Looks alot better than what I had before to work with.
Thanks Texas also, If I don't see what I need I'll take you up on that also.
Birdie

[Texas Trophy]

That BCM diagram that lifted 99 posted is what I have. If you want the entire system for future reference, let me know. You can also use the on-board diagnostics to see if that will help lead you to the problem. If you need instructions on that too, let me know.

[BirdieMod]

Onboard you mean the holding the off and hi heater control buttons for the code displays on the fuel data display. Did that and no codes stored other than E052 which showed dead battery at one time.

[Texas Trophy]

Yea, thats what I mean. Guess no help there huh?

[BirdieMod]

I learned that trick awhile back, About 1995 when I was buying caddies dirt cheap because peeps thought the transmission was bad, Error E030 stored which really was a bad A/C clutch blowing a 15 amp fuse in the hidden panel and the trans was powered off the same circuit. E030 in the book shows power steering problem completely unrated.