This morning I was driving back to my apt. w/ the heat on b/c it was cold, and I had the cd player on. Everything was cool then my CD player started turning off by itself, i thought it was a scratched CD, but looked and it seemed fine. Then I noticed my tach jumping around. I then turned my heat off b/c i was getting comfortable and not cold anymore, and as soon as I did, my tach jumped back to normal and my CD player turned back on and played fine. WTF is going on?

 

I'm damn near certain that the heater and the radio are NOT on the same circuit. Your stock tach I would assume is on the instument cluster circuit. I would take a volt meter and check out those fuses and make sure they're ok. ThenI would go under the hood and make sure you have a sold connection at the underhood fuse box. Sometimes the bolts in there get loose. After that if you have an installer friend, take it to him and see if he knows anything different.

Good Luck.

BTW I'm in Athens... DAWGS!!!

 

you are having a short. like an amp, or the radio itself.

 

short... battery (too much drain load?)... perhaps something to do with the cold? not likely but eh.... I am not an expert, but those would be the things I could imagine doing that stuff underload... especially the battery part, maybe check the connections to it, and clean them if they are crusty... try that kind of load and situation again.