Oil and Temp Gauge Pegged After Cluster Swap

[mm's mj]

Swapped the cluster and both oil and temp are pegged. Replaced both sensors with JY units from a pre-91 that had gauges. Speedo, tach, fuel and volts work perfectly on the cluster.

 

Could I have reversed a harness in the back of the cluster that would affect only oil and temp, or made some other simple boneheaded move?

 

It seems unlikely that both - and only - the oil and temp would be bad in the new cluster.

 

Thanks.

[mvusse]

Could be bad sensors. Could also be idiot light sensors even though it had gauges. Maybe he swapped in the cluster and didn't know how to fix?

[Geonovast]

Could be bad sensors. Could also be idiot light sensors even though it had gauges. Maybe he swapped in the cluster and didn't know how to fix?

 

:agree:

 

There's no wiring you can get backwards. If you managed to get the plug in backwards, nothing would work and you'd probably short something out.

[Eagle]

Check your wiring. The test is the same for both gauges. First, with the ignition on (but the engine not running), unplug the wire from the sender. That's an open circuit = infinite resistance. The gauge should peg to the right. Then ground the wire directly to the block or chassis. Be SURE you have a solid ground connection. That's zero ohms. The gauge should now move all the way to the left.

 

If the gauges don't react this way ... you may have a wiring problem. If they do, you probably have either bad sensors or the wrong sensors.

[mm's mj]

Thanks for your thoughts. I didn't think I got anything wrong with the harness, but stupid stuff happens. I'll run those tests later today - I appreciate the detail.