Sending units

[Brutis]

The fuel gauges have never worked on my truck and there is a leak from the pickup from my front tank. Now that I have a parts beast I thought about snatching the sending units ect... from the 1994 parts truck and swapping it onto my 1990. Are they the same parts or did things change in 4 years?

 

[Diesel JD]

Pretty sure anything 87 and later will work, so yeah I'd give it a try at least. While you have them out take a multimeter and move the arm up and down and see what happens. You should have an ohm range of 158-16 on the newer (87 and later) sending units. Also check the floats and make sure they are not leaking or saturated with diesel.

 

[Brutis]

Good to know. I wouldn't have thought of the multimeter trick.

 

[plywood]

I just looked into this recently and to my recollection the sending units followed the body style years pretty closely.

I didn't however find one comprehensive source of info or keep organized notes.

 

[Diesel JD]

Yeah the 87 and earlier are 78 ohms empty and 10 full. I know the range is 158-16 on the newer 87 and later senders, don't know which direction they go...more resistance full or more empty. Only know for sure they won't interchange.

 

[Brutis]

Thanks again. I guess I'll be looking in the Market place at some point soon.

 

[Diesel_brad]

Yeah the 87 and earlier are 78 ohms empty and 10 full. I know the range is 158-16 on the newer 87 and later senders, don't know which direction they go...more resistance full or more empty. Only know for sure they won't interchange.

Great. Guess i'll have to use 86 sending units when i go over to the powerstroke

 

[Jake S.]

trucks:
80-86 are high ohms empty, low ohms full
87-up are low ohms empty, high ohms full
vans:
at least till 1990 they are the old style, I don't know too much about them, but when the clusters switched to the newer style, they went to the new truck style.

 

[jwalterus]

this is some good info to have, something I never thought of, picked up some aftermarket fuel level gauges so I can monitor both tanks, and wouldn't you know, when I just checked em, they won't work on my truck