Yep,more questions.

 

The oil pressure gauge goes waayyy to hi when running.It also sits below the normal resting place when not running.

The temp gauge will hardly move (I have reasonably hot air from the heater) and the tach sticks at 2K or so randomly.

 

I think someone may have been into the dash for a previous repair (or an odometer rollback).

 

Any suggestions on how to approach these issues?

 

Thanks,Oldmics

sound about right for old loyale put in new oem thermostat oil gauge sounds right normal for low op at idle and high when reved tach probly just sticky beat on top of dash a bitt loosen her up

... The oil pressure gauge goes waayyy to hi when running.It also sits below the normal resting place when not running. ...

 

That usually happens when the wire that comes from the Sender unit at the Oil Pump, becomes loose and does touch the Ground, sending all the ground signal to the needle: It pegs up and then stretches the coil behind the needle, so it sits down below the 0 mark when power is turned off.

 

You can fix & isolate the wire from the sender, also you can "Move" the needle on the dash, to let it sit in 0 again, but it will always be reading lower due to the damage to its coil; however, you can Swap the Oil pressure gauge from another cluster...

 

Kind Regards.

O.K.-Put in the new O.E.M. thermostat and the temp gauge now reads a bit higher.

The heater really cranks now so I am happy with those results.

 

Still have the oil pressure gauge going all the way up as soon as I turn the key to the "on" position.

 

I dissconnected the oil pressure sending wire and as soon as I turn the key on it goes to the max position without the engine being started.

 

So is this a short in the wiring harness?

 

Possibly in the dash cluster?

 

If its in the dash cluster I can also dig into the sticking tachometer issue.

 

Can someone explain the tach operation and wiring to accomplish the tachometer feature.Its obviously an electrical interface of some sort.

 

Thanks for any assistance.

 

Oldmics

If there is a short on the sensor lead I would suspect it to be in the engine area more than the dash since the engine area is less protected. To see if there is a short on the lead you can check the resistance of the sensor lead end while it is disconnected from the sensor and the ignition is turned off. If the resistance between the wire end and chassis ground is close to zero ohms then it is shorted and you will need to hunt down the trouble.

 

For the tach circuit it sees electrical ignition pulses coming from the minus side of the coil that are generated with each firing of a sparkplug. The faster the firing pulses go, the higher the tach speed reading. Usually it is a yellow wire that ties between the coil and the tach in the cluster.

Edited January 30, 201313 yr by Cougar