Gauges acting screwy

[Grendergon]

I just bought a non-intercooled 1991 first gen. It has 231,000 miles in excellent condition. Getrag 360 with 4x4. I'm loving the truck but have noticed quite a few issues with my instrument cluster. All of this has taken place in the last week:

1. oil sensor stopped working, or gave a very low reading. I Replaced it and now it works fine.
2. odometer stopped working, then started working again after about 15 miles ??
3. Fuel gauge started reading lower than it should, then quit reading altogether. Low fuel light stays on when tank is full.

The fact that all these things are happening so closely spaced makes me think there is some common negative ground shared on the instrument cluster causing malfunction? I just bought the truck, but can anyone point me to some common places to check that might save me some time?

 

[mfurrh55]

Cant help you but someone should chime in... Welcome to TDR

 

[Grendergon]

thanks, good to be here-------- great resource!!

 

[BigPapa]

If the truck had been sitting for a while before you bought it, your experience is not unusual. All the gauges you mention are problematic on the 1st Gens. I had a ‘92 and the speedo didn’t work on it. Fuel senders are a known issue.

 

[Grendergon]

Thanks, indeed it was sitting for awhile. The sender was replaced the day before I bought it, so I've ruled that as a unlikely possibility.

More than likely, I think the problem is related to those silly clip on connectors on the circuit board of the instrument cluster. His fix was to solder them, which I think would solve my problem.

 

[GrantP]

2. odometer stopped working, then started working again after about 15 miles ??
3. Fuel gauge started reading lower than it should, then quit reading altogether. Low fuel light stays on when tank is full.

Don't worry, the odometer will likely quit altogether soon...that was my experience. Probably a tiny gear in the cluster somewhere missing a tooth.

Check the ohm readings from the fuel sending unit. More than likely it is in need of replacement too.

 

[sdeeter19555]

I would start by simply disconnecting and reconnecting the connector on the back of the instrument cluster...the pins get corroded with time and that causes issues.

Speedo could also be the sender deal on the transmission/transfercase.

Fuel gauge could also be the in-tank unit failing.