Cadillac Owners Forum banner

1 - 5 of 5 Posts

·
Registered
DeVille 1988
Joined
·
11 Posts
Discussion Starter #1
Hi,

I'm a german student so please excuse my bad english. Thx!
Since a couple of days I´m a proud owner of 1988 Cadillac Deville.
Now I´ve some problems with electric.
What happens:
The preowner of this car make some changes on the Radio. So I want to make it reverse and right. At the radio harness I´ve found a wire with a Voltage about 16V DC. I don´t know how but I think I´ve short circurit this Wire with ground.
Now I´ve the problem that the Odo, Climate Control and the Fuel Computer don´t work. If I turn on the Ignition the displays of these items are dark. If I turn off the Ignition the display short flashes. The Twilight Sentinel works fine!

I have read a lot about IPC and CPS. In a Bulletin I found that these 16V DC are generated by the IPC / ODO.
There are also a Bulletin about checking the Voltages but I can´t find the descripted Pins on the IPC harness.

So my Question. What is broken the IPC or the CPS or something completly different. By the way I´ve checked all Fuses, there was no defect. Damned!

I hope you can help me!

Thx
 

·
Registered
1992 Sedan Deville, 1984 Lincoln Town Car
Joined
·
759 Posts
Hi, just read your post. I have 92 Deville but I think electronics is the mostly same. 16 Volts is common, wired in parallel not series, with FDC, ECC, RADIO, and IPC, but not the Twilight Sentinal. It controls the Vacuum Fluorescent (VM) display on all of the 4 units.

Your "short" is keeping the 16V from the display but if you can measure the 16V on the one wire you said, Radio, that fact is good. It means the CPS (Central Power Supply) as you call it (mine is BCM- Body Control Module, same thing) 16V regulator is still good not dead. Whew, lucky!

Now to find out where is the short :want:, wire or unit???. Try to unplug each unit one at a time maybe. Radio is easiest, then FDC etc. then see if circuit works without it. I'll go read a little more on my schematics.

OH yes, one question, Is your 16V wire color Orange/Black? the other side would be Purple/white to Gnd with Ign switch in RUN.

I will return to check and see if you got this post.
 

·
Registered
DeVille 1988
Joined
·
11 Posts
Discussion Starter #3
Hi Amencaddy,

My 16V Wire is orange with a small black line on it (also orange/black). Looks very similar up to identic to the 12V Wire on the Radio.
Unfortunately after removing the short the 16V are still dead.
So you mean I have no CPS because the Power is generated in the BCM?
I don't know!
German cars electric are different to the Caddy. :confused:

Where can I find the BCM. Near the steering column and Pedals are nothing.
On passenger side I guess I have Found the ECM. Large silver Box with to plugs. Behind the glove Box I have found a small silver Box with one plug. Is it these?

Regards
Julius
 

·
Registered
1992 Sedan Deville, 1984 Lincoln Town Car
Joined
·
759 Posts
Hi Julius, nice name. Mine is Juliet (as in Romeo and...)

Are you in Germany then? If your car is European version of the Cadillac.

The BCM is where the 16 volts Regulator is. the Orange/ Black wire goes to all those 4 units mentioned. It is located kind of in the middle above the Radio area. big box, lying flat with 2 long 2-row connectors on the right side toward the glove compartment. can't miss it.
Of the 2 connectors,. the longer one (C2) has the 16V orange/black wire. no other Orange/black on there. check there for your 16V to Gnd. Ign must be in RUN position (Hot in Run)

Let me know the news.
 

·
Registered
DeVille 1988
Joined
·
11 Posts
Discussion Starter #5
Hi Juliet,

I have replaced the BCM behind the glove Box. Now all Instruments works fine!
The part costs me 50 bugs. Not the cheapest one but it was quick available.

The Caddy is here in Lansing Michigan. I have an internship for the next six months. But I am still thinking about to take this car with to Germany. We will see....

Big thanks for your help!!

Bye
Julius
 
1 - 5 of 5 Posts
Top