Re: High Volts and oil pressure
In my humble opinion,
Your alternator voltage regulator is junk. You didn't say if you have the internally regulated delco alt. or the externally regulated mopar or ford types. I have seen all types do this very thing. I just fixed my sister's ford truck this week with the same problem. Gauges will go up or max out, but 'idiot' lights will never come on. The crucial test is... do the gauges move together? The volt meter goes up, and the other gauges go up too?
If they don't, it is something else.
Testing yourself is a real pain! Most of the time it is caused by a bad Alternator ground that kills the regulator, and it is normally an intermittent problem making it hard to diagnose.
How many of you actually have a dedicated alternator ground wire bolted to the back of the ALTERNATOR, (not the bracket) and using star washers to get a good bite? Wire at least 10 Ga., and should be a 4 Ga., and run back to the battery?
Battery ground wires should be at least 2 Ga., and run to a starter bolt with a star washer.
Your alternator ground wire can also be the ground the engine, but the body and frame need solid grounds also.
Chances are your gages are damaged by now if the voltage exceeded 18 volts. Your engine temp gage and your oil pressure gage should always be mechanical anyway. I am a BIG fan of Autometer gauges, and you can keep your second set under the hood
(old racers trick), or in a hood scoop or cowl scoop.
If a gauge reads stupid, or an idiot light comes on, you can raise the hood and get a second opinion real quick. Mechanical gauges work even if the electrical system gets yanked out of the vehicle, and you have to limp home with just the distributor wired to the battery. (Been there... it wasn't pretty)