Hello, I am new to this forum, and wanted to see if I could get some help. I have a 1969 Plymouth Satellite with the 225 slant six. I also have a 1980 Dodge Ram pickup with the same motor. I recently purchased the truck, and it has the same problem I have been battling for years in my convertible. The problem is this.

The gas gauge and the temp gauge in both vehicles doesn't work. The fuel gauge moves in both but doesn't read correctly. The temp gauge doesn't work in either vehicle. I have replaced the instrument cluster voltage regulator in both vehicles and it hasn't fixed the problem. Does anyone have any idea where to go next. I wouldn't ask, but the same problem in two unrelated vehicles seems odd to me. Thanks in advance for any help. Thanks.

 

I would replace the temp guage sending unit. It screws in the head.

I'm not sure because it's been so long since it 'screwed' around with the slant 6. "I Think" the newer 6 the sending unit is in the front of the head. The other is in the back. Or vise virsa.

Stay away from Auto Zone or Advanced. The reason is, those counter jockeys don't know 'dick' about older vehicles, because it isn't on their computer, or easily axcess to a book.

Go to NAPA.

Those sending units, there is one for guages and one for idiot lights

The oil pressure sending unit is a great big ugly lookin' thing that screws into a oil galley on the block. I think they are next to the oil filter.

Same thing with them, Go to NAPA Or Year One might be of help

 

As for the fuel gauge, I'd suspect the sending unit in the tank, especially since you say "it moves, but not accurate". Sounds as though it is getting electrical current but float may be bad or some corrosion on the unit itself is not allowing the float to move freely, thus not reading appropriately. The 1969 one is definetly due for a change. My 69 Road runner float had a small pin hole in it that made it "sink"...pretty common on these old cars.

Good luck.