Gauges Stuck

[Shawn0331]

Just noticed this yesterday. All gauges except for speedometer have stopped working. My voltmeter is stuck to the left, temp is stuck between 100 and 210, and my fuel gauge is stuck just above 1/4 tank.

Any idea why this might have happened?

[78 Chevyrado]

I'd check the big connector on the back of the gauge cluster to see if it's come unhooked.  That's what it sounds like to me.

[Shawn0331]

Blown fuse... Works again.

[bake74]

Blown fuse... Works again.

        Wouldn't it be great is life was that simple.   

[Shawn0331]

Blown fuse... Works again.

        Wouldn't it be great is life was that simple.   

It would be...blew the same fuse on the way home last night.

[Shawn0331]

I'm waiting for the fuse to blow again but it's held up so far today. Any idea where I should start troubleshooting?

[Shawn0331]

It's the gauge/idle fuse. I see that it runs the gauges, but what's it doing with the idle? It runs just fine with the fuse blown/removed.

[slammed79]

I'd start with checking the plug as mentioned, then the wires for the gauges. Also check the grounds

[Shawn0331]

I'd start with checking the plug as mentioned, then the wires for the gauges. Also check the grounds

So pull the gauge cluster?

[bd]

The 'gauges' fuse may protect multiple ignition circuits, including the 'Ign' taps on the fuse box.  Your problem may not be restricted to the I/P and cluster.  You might want to start by quickly surveying which appliances don't work with the 'gauges' fuse removed/blown, then install a new fuse and see which of those inop circuits now work.

Tech Tip:
To diagnose shorts without spending a fortune in fuses, take a 10-amp, auto-reset circuit breaker that will fit your fuse box and connect a 12-volt non-polarized alarm module (like a seatbelt warning buzzer) across the blades of the breaker.  Replace the blown fuse with the circuit breaker/alarm.  Now, every time the circuit shorts, the breaker will open and the alarm will sound... until the breaker resets.  It helps save time when your crawling around under the dash, hood, etc.   

Before taking the cluster back out, begin by installing the breaker, then reaching up behind the dash and g-e-n-t-l-y nudging the harness to see if you can recreate the problem.  Expand your search from there.

[Shawn0331]

Thanks for the tip. I'll try and get to it tomorrow.

[Shawn0331]

I haven't had more time to look at it, but after doing a some research (and chatting with my neighbor about it), I think my problems are related to my missing oil pressure sending unit / switch.

Looking at the wiring diagram on Autozone, I found that the oil pressure sending unit is part of the circuit. I already knew that I've been having an issue with the fuel pump running after shutting off the engine sometimes (which also is connected to the oil pressure sending unit).

Hopefully tomorrow I'll have time to check behind the distributor for the tan/white and/or gray wire that is supposed to be connected to the oil pressure sending unit.

[Shawn0331]

Here's what I found that's making me think this too.

http://www.chevytalk.org/fusionbb/showtopic.php?tid/263217/

[bake74]

      So your saying that you think the wire that is suppose to be hooked up to the oil sending unit is bouncing around and shorting out against something ?  Easy way to find out is tape off end and attach wire where it is secured somewhere to see if it stops blowing the fuse.  ( I use Bd's suggestion at work all the time, but with resettable mini circuit breakers, saves a ton on fuses  ).
      Or do you think that by not being hooked up at all it is blowing the circuit ?

[Shawn0331]

I'm thinking it's bouncing around. I remember not finding the switch when I pulled the distributor cap a while back. I did find a bolt in its spot though.