[caddydaddy]

I've been having a high voltage problem on my '94 Deville 4.9. I had to replace the starter and when I did so, I noticed some of the wires had the casings worn through. The wires themselves were in bad shape, so I cut them and spliced in some new wire and connectors. That day, I had to make a 350 mile trip, and after about 100 miles, I started noticing my headlights flashing a bit. Then my air bag warning light started flashing, then the DIC message read "Battery Volts High". I checked the volt meter onboard the DIC, and it was reading anywhere from 14.1 to near 16! I managed to get the car to my destination with the only damage being blowing both my high beam bulbs.

I figured it was just a faulty voltage regulator in the original alternator, so I replaced it with a new one the next day. After a short drive, the problem still existed! I have since double checked all the battery connections (the battery is 2 months old), and I have cleaned both the ground wire connections (on the engine block and the one to the chassis in front of the battery).

After that, the problem has never gotten as bad as before, the voltage might get up to 14.7 or so, and the "High Battery Voltage" message doesn't show up on the DIC anymore, but the air bag warning light will flash, as does the headlights.

Everyone I've talked to says I probably have a bad connection somewhere, but I don't know where! The only thing I can think of, is when I respliced the wires for the starter, that there is a bad connection in one of the splices. The positive lead I didn't touch, that was fine, but the other two wires I have spliced and put on new connectors. So, I guess the only thing left I can think of to do, is to re-do the wires that I crimp-connected, and solder them to hopefully get a better connection. I only hope that is the problem. I've thought it may be a battery problem, but I'm not sure. And if there was a starter wire problem, I would think I would have problems starting it, which I don't.:hmm:

Thanks for any advice! :cool2:

 

[Eldyfig]

My first guess would be the alternator also. You say you replaced it though, correct?

Have you tried draining the battery down to about 12.5V by leaving the lights on for some time while the engine is not running?

How about the plug on your alternator? Is it connected firmly?

 

[caddydaddy]

Yes, the alternator is new. I replaced the original one because I thought this problem was with the alternator. If the car has sat, and I start the car up, the battery volts will be around 12.3, then it will charge up to the high 13's low 14's. But once in a while it will spike up to high 14's even 15's.
A strange thing happened this morning though, the air bag light flashed again, like it always does when the voltage spikes, but the DIC message said "No Battery Charge". But the voltage was around 14.7 or so. So I really don't know what's going on, or what to do!

 

[Eldyfig]

How about checking the wiring to that plug that connects into the side of your alternator?

 

[caddydaddy]

The positive cable is on tight, but I'm not sure what the plug controls? The voltage regulator?

 

[The Ape Man]

Lose the crimp connectors first and see what happens.