Help needed- temp gauge not working (1 Viewer)

[JustOneMore]

I’ve known the temp gauge in my 40 didn’t work since I bought and it’s never really bothered me. About a week ago though I had an issue where I thought it might be overheating and was really wishing it worked. So I’m trying to make that happen. I started doing some reading and testing.

I started with the gauge. The PO installed a mechanical temp gauge at some point and just unplugged the factory one. Since I’ve had it the needle on the factory gauge has always been on H. I grabbed a jumper wire and used it to ground out the sensor wire. When I did this the needle went to C and when I removed the wire it went back to H. I think this means the gauge is good?

My next thought was to buy a new sender. This is where I got a little confused. From what I understand there are two different senders, an early style and a late style with different resistance ranges. My 40 is a 12/71 build which I believe is supposed to have the early sender. My gauge cluster is in km/h though because at some point the PO changed it out. I believe it is a newer one because it has a clip-on speedo cable. Can anyone tell me if that means the temp gauge might be calibrated to work with the newer sender? I’m not sure they’ll really help but I took a few pictures. The sender that is in the pictures is from the mechanical gauge.

 

[45Dougal]

Sounds like your old style gauge is working fine.
I say old style because the needle is at rest in the high position.. on the newer gauge, the needle would be at low.
The senders have opposite resistance ranges, so they are not at all compatible.

You just need to find the correct long sender and nipple as i understand.
Speak to.. https://forum.ih8mud.com/members/toyotamatt.25798/

A cheap alternative is to buy a thermometer with a long thermocouple which you can just glue to the block.
I bought one for mine while I was fixing it.

 

[JustOneMore]

Sounds like your old style gauge is working fine.
I say old style because the needle is at rest in the high position.. on the newer gauge, the needle would be at low.
The senders have opposite resistance ranges, so they are not at all compatible.

You just need to find the correct long sender and nipple as i understand.
Speak to.. https://forum.ih8mud.com/members/toyotamatt.25798/

A cheap alternative is to buy a thermometer with a long thermocouple which you can just glue to the block.
I bought one for mine while I was fixing it.

That is exactly the information I was looking for! Thank you!

 

[65swb45]

It looks like the PO put the newer speedometer into the original cluster; the wiring in your pic looks standard for your year.

www.marksoffroad.net

 

[JustOneMore]

It looks like the PO put the newer speedometer into the original cluster; the wiring in your pic looks standard for your year.

www.marksoffroad.net

That’s kinda what I had figured by looking at lots of pictures but I was hoping someone else could confirm. Thanks!