Temp Gauge Pegged

[st0rck]

Ok, I searched Google and the forums but was completely unable to find a solution to my problem. I will start from the beginning (if anyone is wondering the steps to follow were mostly performed while the truck was only running on 4 cylinders but that has since been fixed)

Bought 84 Grand Wagoneer w/ 258. Had been sitting since 2005

Fuel gauge, temp gauge and ammeter gauge were inoperative.

Ammeter has been removed (wires connected) as the gauge is broken.

Bought a brand new temp gauge from Bjs and installed it. Presto! Temp gauge worked, fuel gauge did not.

Bought a brand new fuel gauge & sending unit from BJ's. Presto! Fuel gauge worked!

Drove truck a few times (not often since she ran like crap which has since been attributed to having been running on only 4 cylinders), looked down and noticed that gauge was pegged. Oh no! Blown head! Or was it....

Truck sat for 3 days, went out, turned key to on, DID NOT START TRUCK, and Gauge pegged Hot. ERMEHGERD!

Replaced Sending Unit on back of head (drivers side near firewall). Problem still persisted.

Removed wire from sending unit, problem still persisted.

Swapped new temp gauge w/ old temp gauge... old temp gauge pegged HOT, as did fuel gauge peg full (I figure this was because it was bad as I know my tank is nearly empty).

Cut wire approximately 5 inches back from connector on back of gauge cluster. Gauge stopped pegging. Yay! Bad wire...?

Installed completely new wire from where it had been cut (I also cut the last 4 inches of the wire off so I could re-use the connector for the sending unit).

Re-installed everything, turned key to On.... Gauge pegged to HOT again!?!?

Cut sending unit connector end off that I spliced on to see if that was the problem since I know it wasn't the end coming out of the gauge cluster, problem didn't go away....

So now I am haplessly confused.... someone help! Where do I go from here?!

[Ryan]

the pegging means you have a short / ground somewhere on that circuit

[davpratt]

I assume it was the purple wire with a white tracer you were messing with?
Your vehicle has a 6 cylinder. Some 8 cylinders had two temp sensors.
May be the one not used is shorted to ground.
Pin C should be the pin on the dash connector.

[st0rck]

Yep purple wire with the white tracer. Spent the last 5 hours in the dash and under the hood. Disconnected and checked every single wire (I never thought there would be so many wires on an older car)! FINALLY figured it out, or at least so it would seem... turns out that I guess I put the nuts on just a wee bit too tight on the temp gauge.... as a last ditch resort I loosened them up and the gauge finally stopped pegging... tightened them down finger tight one at a tight and problem has gone away... hopefully for good... hooray! Wish I had tried that prior to running a brand new wire...

Mine did have two sensors, one was on the intake manifold the other was on the head but when I put the old school intake setup on the one got deleted. There was only the one connector though which was ran to the one on the intake (now to the one on the head).

Now on to the next problem... no power (well very nominal power) going to the right rear turn signal... sigh...

[Brent]

Now on to the next problem... no power (well very nominal power) going to the right rear turn signal... sigh...

This is typically a ground problem. Check and clean your grounds going to the rear lights and see if this solves it.