Weird battery light on reverse only!?!

[tripletdaddy]

On my 95, 3.8L with original alternator and under 1 year old battery, the battery light would come on. I was backing up the van up a slight incline when I first noticed it come on, but it would immediately go off when the load and rpm would drop. I tried to repeat it in forward up a hill or power braking, high beams and ac on high, nothing. It ONLY comes on in reverse. It doesn't make sense to me.

A while back, I thought I either needed to replace the alt or rebuild it with new brushes at least or also the voltage regulator. Never did anything as the light stopped coming on, but this problem occurred under different circumstances. I'm in no hurry to do anything as the light isn't coming on 99% of the time. But, I would like an explaination as to why it is acting weird like this. What's so different about reverse from forward to make the light only come on in reverse?

[12Ounce]

Are the motor mounts worn enough so that the alternator wiring gets "pulled" in a unique way when backing up?

[tripletdaddy]

Interesting idea, 12 ounce. I will have to investigate that when the van returns home. I wasn't aware of such wear of the motor mounts, but I certainly will entertain such a simple test and post back with my results.

[tripletdaddy]

Tried getting the motor to rock in forward and reverse with brakes on and wheels chocked. The engine didn't move like the mounts were bad or make any noise either. I did watch what the movement did to the wiring to the alt. Drive stretches the wires and reverse pushes them.

Interestingly, when I began the testing, the light came on as before. So, before I did anything else, I tried to adjust the wires and connectons. The light went out. I was not able to get the light to come back on thinking this could be a wiring, connection problem. When I tested the motor mounts, the light never came on and didn't come on will additional attempts.

So, for now, I'm just going to not worry about it. Ignorance is bliss.

[12Ounce]

Stay happy!

While you're checking connections, don't overlook the ground connection at the starter motor.