Ok guys, I need some help again please. When I start the car I can keep a gauge cluster fuse in it until I try to drive it. Here's what happens, the other gauges work fine, but the tachomer shows that I'm running 7,000 rpm, but I'm actually running around 650 rpm at idle. I put it in drive, take it for a ride around the block, rev it up a couple of time and the tach goes back to normal. The car doesn't run well in drive by the way for some reason I'm trying to figure out. Once the tach goes back to normal, I give it a little gas and once the tach shoots past 2,000 rpm, it blows the gauge cluster fuse. I put a new coil, ESC module and ignition module in, and can't figure it out. I think it has to do with the ignition system, but what could cause this? Is there another sensor, fuseable link, or ground connected to the tach wire or to the coil to cause this to happen? Any help would be very very much appreciated. Thanks guys, I'm desperite at this point.

 

Hi,

I'm no great expert here, I was just browsing and I saw your question so I thought I'd respond. I have an '89 T/A, 305 TPI. For a few years, when it was a lot newer, there were some problems with the computer chips and 2 or 3 times the thing would suddenly start going crazy and make all the gauges read funny. That's the only time I saw the tach act wierd. It just needed another chip. Just a possibility you might look into.

 

if you are blowing a fuse then you have a short somewhere in the car. Have you ever takent eh dash apart before. maybe a wire was pinched and now its arcing out somewhere. I dont think its a chip problem. Definitly a short. look behind the dist to see if there is any wires rubbing. if you have worked on your car brfore with wires then double check them all. our cars wiring sucks so anything can happen.

 

Actually, before you start tearing into fuses and stuff, find the tach lead and follow it all the way from the distributor until it goes into a wire pack which goes into the firewall. It almost sounds like the wire could possibly melted against your exhaust manifold and shorting out, or maybe just have bare metal exposed and shorting against something. Also, make sure the tach lead is firmly plugged into the distributor.

 

Yeah, I'd check the wire leading to the distributor.