I got the car running good last night after many weeks ( I mean months, engine swap)of trouble.
Then I saw a flash as the fuse box and it started to run like crap.
the tach stopped working.
the fuse was for the instrument panel.
why would this fuse cause it to run bad?
those gages aren't tied in to anything else are they???
played around with the wires under the dash and got it to take another fuse without blowing, then running good again.
then after a little while, bam blew the fuse again. runs like crap.

(tach is off as far as rpm goes, always has been)
what do you think?
thanks
Scott

 

It the failing fuse the INST LPS fuse, or the GAUGES fuse?

The GAUGES fuse protects the circuit that includes the EGR solenoid, AIR Select and AIR Divert solenoids, EVAP Purge solenoid, MAF Burn Off relay, MAF Power relay, A/C compessor, Rear defogger, cruise control, VSS power, tachometer, torque converter clutch, and the rest of the I/P gauges.

Losing the VSS, MAF power, or other afected sensors can affect the way it runs.

 

Thanks Vader,



It says gages, on the fuse box.
I guess I will be tracing some more wires tonight. what fun. Its been a long prodject, and its tough working on it out side.

I did see a flash around the steering column near the tach.
about the same time there was a flash at the fuse box.

Do you are anyone know of a good service manual for this thing?
does the GM service manual cover everything, trouble shooting and drivability?

where can I get one??
thanks
Scott

 

Get your trusty ohmmeter out and ready.

Disconnect the EVAP solenoid, and measure the solenoid coil resistance. It should be at least 35-50 ohms.

Do the same for the EGR solenoid. Then for the AIR solenoids. All of them should be at least 35-50 ohms. Anything around or below 15 ohms should raise the red flag. Of course, there may be a problem with the wire harness to any of those devices, and checking the solenoid copil resistance would not reveal that.

Since the fuse failure is intermittent, I'd suspect one of the solenoids, since the ECM will operate them at various times under a range of operating conditions. That may not be the case, but would explain the random nature of the fuse blowing.

A flash from behind the I/P can't be good. The tach electronics are there. The VSS is there (on Camaros). Either could be a problem. The foil circuits for the rest of the gauges are also there. Anything shorting across the traces could be a problem if it happened to cut through the protective plastic covering.