1998 Cadillac Seville V8 Front Wheel Drive Automatic 70k miles
Give this Cadillac Seville question to:
1998 Cadillac Seville sls
Key-on engine-off, all electric works, info center displays correct info, radio, all lights, windows ac-fan, windows, etc. Works.
But with the Engine running; dashboard acts erratic, shows categories but no data-info, gas guage goes from 1/2 fuill to empty and back again over and over, headlights are on but you can't turn them off, windows don't work, radio lights are on but no sound from speakers, ac-fan speed switch works but no ac.
Car-engine starts, runs, can be driven ok except for the electrial problems listed, no ac, windows, radio, etc.
I Checked the battery, it has full proper volts with engine off and on.
Driver says that the Add coolant light has been on for 1 month but the temp guage has always been right in the middle. I checked it, it needs about 1 quart, I Just bought some premix dex-cool, haven't put it in yet.
Why does everything electrical work with key-on-engine-off but not when the engine is running?
k-o-e-o: You get data on every reading. Bell works when the key is in and the door is open and when you turn the key, gas guages work, fan works, windows work, headlight switch works, radio works, volts show as 12.0-ok.
But when the engine-is-turned-on and running all of the problems begin. Fan works but no a/c. Radio lights up but no sound from speakers, windows don't work, headlights are on but can't be turned off, info display shows up but loses all data.
I had the owner basic-test the electrical components with key-on-engine-off for only 5 minutes, the battery-volts was showing 11.0-ok at first on the display and a few minutes later when checking it again it went down to 9.0-low volts on the display?
And then when checking the volts again on the dashboard/info display now there was no data for volts.
The battery should hardly have been affected by this low-level of testing.
All we did was checked that the bell was working when the key is in and the door is open a few times, and go through the dash-display to see that there was data for each category. Turned the radio and the fan on for a minute or 2
I have a battery charger and will go over there to charge the battery and get the car running again. I have a codescout 1500 scan tool and will use it. Any suggestion what to look for?
update: The battery was at 5, 6 volts, I charged the battery on a 10 amp battery charger for a lomg time and it then was up to 14.3 volts with a multi-meter.
I started up the car and the electric was acting erratic as before, after 10-15 minutes engine running everything started to work as it should, radio came on, ac was working. Windows and all lights worked, dash info showed all readings.
Voltrage read as 14.0, with AC on it went to 13.9. At first with everything working the radio light and sound would just cut out and come back on, once the ac cut off and came back on. After awhile everything was working ok.
But you could tell that the problem would be coming back.
The next day upon startting the car the dash display showed no info for the different readings just dashes.
I'm waiting now to see how they did because they had to use the car to go somewhere.
I will update this as soon as I hear how the car did on the road.
We cannot fix this ourselves, unless it's an easily accesable repair and/or parts. We'll most probably have to take it to a mechanic, but we want to try and figure out what's wrong with the car-electric, rule-out unneeded expensive mechanic quotes, such as unneeded computer repairs-parts, etc, befiore we give the car to a mechanic for an estimate-$$$
Can you help me diagnose this problem.
Wednesday, August 18th, 2010 AT 3:30 PM