1988 Chevy S10 Tahoe Many Problems

Hmm how do I start?

I have had my stereo about 5 months and been waiting for warm weather to fix it. I have a lot of problems. Usually when I go over bumps my stereo will shut off. Also when I close my door the voltage will drop low enough for my stereo not to work. My dimmer switch on my dash makes my voltage go way up (about 14v)when it is turned all the way up, but when it isnt turned off the voltage goes way down to (about 9V). The dimmer switch wire is not connected to my stereo although a wire for it is in the area  where I installed my headunit. The only lighitng wire for my stereo which is a JVC KD-LH810 is an illumination wire which is hooked up to my car audio illumination wire. Today I thought that the problem was the door switch for the light that is turned on when the dimmer switch is all the way up. When the door is closed the switch would be pressed for the light and the voltage would go down to about 9 from 14. So I unooked these two switches on both my doors but it only made a constant low voltage. Please help... Im so sick of this problem, about to just give up.

I decided to update my thread do to how it seems very confusing...

I have narrowed the problem mainly down to my interiour lighting effecting my stereo. When I turn on my headlights the stereo will cut out, this is both when the stereo is and isnt hook up to the illumination wire in the truck. The voltage to my stereo is at about a constant 14v... could the headlights be drawing so much power that my stereo shuts off?

IMO  I dont think you need the illu. wire hooked up for operation. And if the H.U and the interior need more voltage than they are recieving, it could cause a problem like that....

First check your battery's connection.  Betcha 6 donuts one of them is loose.  Next disconnect the illumination and make sure all of the wire connections are insulated.  Finally run a secondary ground to a portion of the car's chassis making sure to sand the metal before grounding...