Hi I have a 1980 ford f250 custom 4x4 extended cab truck. currently the tempature guage isn't working so I got told I needed a tempature sending unit. So i bought one and im not too sure where it goes in the engine. My trucks engine is a 6.6 Litre 400 . Some help would be appreciated asap thanks a lot.

 

Before you put the sending unit in and find out you don't need it, let's do a test. In the morning I'll post a picture of my engine and show you where the sending unit is. Then you pull the wire on it off and hold it against ground. Then turn the key on - if the temp gauge moves up to HOT after a few seconds the sending unit is bad. But if it doesn't go up then there is something else wrong, like wiring or the ICVR, or....

Does the oil pressure gauge work? The fuel gauge?

 

Yes, do the diagnosis Gary suggests before replacing parts....

 

At this point you can take the sending unit back. But not after it is installed. And, my engine is on a stand so taking a pic will easy. Will even look up the wire color to boot. First thing in the morning - after coffee.

 

Sending units are cheap, just put it on.

 

Attached is a picture of me pointing at the temp sending unit on my engine, which is the little brother of your 400. But, I may have swapped the factory sender with the aftermarket one, so yours might be just below and right of mine, in what is an open fitting in the picture.

In any event, the wire on it should be red with a white stripe, although that is frequently hard to tell after 32 years. Pull it and hold it against a ground, and with the key on the temp gauge should go full hot if the sender is the problem. If it doesn't then the problem is elsewhere.

 

Hey thanks man that worked perfectly !!

 

Glad it did. But, does that mean you replaced the sender or??????

 

Yeah I had to replace it the old one was toast