I have a 1995 Isuzu Trooper with 157,000 miles. While taking my son to his girl friend’s house the AC fan acted like it turned itself from high to low and then back to high. Then I noticed that the Check Trans light was on. I stopped and checked the fluid level. The fluid was clean and at the proper level. When we got back on the road I realized that it wasn’t only the “Check Trans” light but also the Air Bag light and the little Battery Icon and a couple more lights that I can’t remember. Anyway, this happened all the way home. The lights would blink on either some of them or all of them. The Transmission would act clunky and then the lights would go out for a while and everything would work fine. When I got home I let it Idle while I looked under the dash and I noticed that when the lights would start acting up there was a clicking or kind of buzzing sound coming from a silver box under the dash to the left of the steering column with a lot of wires coming out of it. I measured the box (about 1-1/2" wide by 6" tall and about 5-1/2 inches deep.) The box was really warm almost hot to the touch.
Any ideas what this box might be and whether or not that might be my problem? Might the buzzing/clicking sound just be a symptom of the real problem?
The box you describe sounds like it is a electronic control box for the body at least. It may also be for the engine. I would first check to see if the alternator is having a problem and check for any AC voltage at the battery while the engine is running. Also check the DC voltage. There should be no AC voltage across the battery terminals and the DC voltage should be at least around 13 volts.
Have a competent shop check your alternator. Sounds like a bad diode causing an AC ripple to disturb your electrical system…
I agree with Caddyman. A failing alternator can cause a lot of random events to take place with your dash panel warning lights and controls. If I am correct, the alternator is due to quit totally within a matter of a day or two.