Hi all. I am brand new to this but I am at my wits end, so any idea will be welcome. The subject is an 88 IROC-Z, 5.7 . The problem is the gauges fuse keeps popping. At first I thought it might be a loose wire somewhere. The other night on my way home I hit a slight bump and it popped. I pulled over to replace the fuse which had been fixing it for a time. I pulled the emergency blinkers and switched. As soon as I put the key in the on position it popped. just to double check I tried it again and same result. I appreciate any help or advice anyone could give, this is my baby but she is driving me bonkers. Thank you again

 

Your fuse is popping because you:

1. You have too much load on the circuit
2. There are too many amps going through the fuse
3. or the fuse is the wrong type/size

Make sure you indeed have the correct rating fuse for the gauges. If so, I would track down the wire leading to the fuse and make sure the wire is in good order and not shorted to anything.

Last, if those don't work, I would check and make sure your related relays are good.

 

I had a 20 in there before and it blew. I have not done any rewiring to the car and the wire running from it looks fine. Why would the load or the amps going through it suddenly change? Thank you again

 

Is there anything else that doesn't work once the fuse has blown? I'm thinking about additional load a previous owner may have installed; stereo, fog lamps etc. Although, that fact that it went after a bump would certainly suggest a short somewhere.
Jon

 

just the gauges Tach, fuel, oil pressure, and battery

 

Your fuse is blowing because you have a short to ground. If you can find me a wiring schematic for the gauges for your car, I should be able to help you pinpoint where the wire is shorted.

 

The gauges fuse runs many things: inst panel gauges, vss, chimes, air and canister purge controls, etc etc. This diagram is for an 86, but most would apply I should imagine:

http://92b4crs.tripod.com/86wiring/dia-pics/11-7.jpg

All these things should stop working if it blows - if they keep working, sure u got the right fuse? If not, you've got a whole bunch of things to check.

 

I agree with treefiddy. If that fuse blows, you will lose alot of things. What I can see as the main things would be gauges, brake lights, rear defogger, cruise control, and mass air flow relay. The other things not too important would be emission stuff. Does the engine run ok? Losing the mass air flow relay I think would make the engine not run right. Also check your brake lights to see if they are still working. Being an 86 diagram, it could be wrong as gm could of redone the wiring for the 88 model year.

 

Shorts can be a real pain to trace down. Because it is an inermintant problem I would agree it is a short to ground. There are wires behind the stereo and under the center console as well that have a higher chance of getting shorted. I would remove the radio (completly) and the shifter top plate so you can see under it. Next replace the fuse and turn on the parking lights. Whether the fuse pops or not wiggle the wires where the radio was and the wires going below the center console to see if these wires cause the fuse to blow. This will aid in eliminating or locating the issue. I would continue removing things and giggling wires until the area is located. Once located it will be much easier to locate the problem. Option 2 would be to go throughe the wiring scematic and take readings to everything in that circuit which is very time consuming but affective if all else fails. . .I prefere to start giggling and work a small section of wires at a time to speed up the process.

 

the only things that I notice that are shutting off are the guages (not the Speedo) it was intermittant now it is constant. also at night with the fuse blown when I turn my headlights on there is that wonderful warning beep that usually only tells you the door is open with your keys in the ignition. it goes nonstop. The cruise control has not worked since purchase of the car. Engine still runs well I replaced the MAF sensor a couple years ago. I have a schematic for the instrument panel & warning lights system from my Haynes scanned onto my computer but have no idea how to load it up here. Thank you all