Temp gauge issues ?

[UK4x4]

trying to track down an issue on my RJ77 and need help

Just bought the truck and the gauge sort of moves from just under C to just above C when hot

Changed both the sender and the gauge, cleaned all the contacts on the dash cluster and soldered the twisted wire joint at the sender...same thing.

I got both from TOYO using the chassis no.

There were two supplier parts in the catalogue for the sender ...which might be a clue

Q any one have an RJ77 or other 70 series LC and measure the resistance of the sender when cold ?

The wire to the sender is a rewire job too and wondered if the original conection had an in line resistor...or in paralel to adapt the 70 series gauges to the R22 rather than the usual six cylinder.

Mine reads 700 ohms at room temp and 300 ohms with hot water from the microwave.

which means If I wanted the gauge to read normally I'd have to add resistance in parallel to lower its total resistance or a lower resistance sender

 

[roscoFJ73]

FSM says sender gauge at 50c it should be approx ,226ohms +33.6 -36.6 and at 115c 26.4+1.71 -2.21
Receiver gauge - 55ohms

I got that from the 84-90 Body Chassis manual for 60 and 70 series,pages BE35/36.
Not sure about the suppliers but so far Ive found them interchangeable(oil pressure as well)
The manual seems to have only one test result for all,so I guess you could assume they are all the same.
The free manual downloads have schematics in them also(tpp of forum

 

[UK4x4]

cheers for that, I was searching the engine section.....oh well beginners mistake...off to download the body section

Is that measuring at the rear of the gauge or the sensor itself ?

 

[roscoFJ73]

Is that measuring at the rear of the gauge or the sensor itself ?

I posted 2 groups of readings,so I assumed one of each.