I've found a gauge cluster in a yard here and can't seem to figure out how to get the oil pressure sender off the block...

It looks like between the sending unit and the block there is a bolt head which would be impossible to get from above (unless removing the oil filter would help?)

Am I correct in assuming that I must get an open end wrench on it from underneath the vehicle? Anyone know what size wrench I'll need?

tia,

jack
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Bad Blue, '86 245, 250,000 mi., Columbus, Ohio

you guys were right... no way to get to it even from below without removing the alternator...

17 mm to get the sender off the adapter nut

19 mm to get the adapter nut off the block.

pretty good memory JonB.

thanks guys,

now all I have to do is install and remember which wires go where!!!

jack
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Bad Blue, '86 245, 250,000 mi., Columbus, Ohio

I've had success from the top, but I had to swing the alt out of the way. I think I used a 17 open end to remove the sender and a 10 to get the fitting. It's tight in there but is possible, good luck!
-JonB.

I second the idea of pulling the alternator. I extracted my oil pressure switch and gauge from an '83 Turbo in the part yard. My big hands couldn't fit a wrench in there without removing the alternator. After that, there was enough room and I didn't need to pull the oil filter.

Good luck and God bless,
Fitz Fitzgerald.
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'87 Blue 245, NA 214K