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Looking for 1970 oil pressure sending unit for rally gauges

I'm looking for an original AC sending unit. It can be used or nos. please let me know. [email protected]. Thanks Imran

make sure you get an 80 lb.....other lines use a 60 lb..looks identicle..but stamped 60

I have one off a 68 don't know if this is what your looking for same ?

Peter Serio could tell you for sure, but I believe it would be the same as the one he told me to buy for my 67 GTO.

It was a Carquest unit and tested exactly right. Can't find the part # just now, but will keep on looking.

thanks 1966geeto can you send me a pic of it, my email is [email protected] or tex me at 905 414 7373 Imran

I asked Scott and he said he would get me the part#

also, watch out, the buick and oldsmobile have a diff threads..68 gto should be right...

GTO Chevelle Camaro and truck seem to all be right numbers..

Found that sender info.

Quote:

Hi, I use air pressure and an ohmmeter to test my oil pressure sending units. (New or used.) You can make an adapter out some fittings you can buy at Home Depot or Lowes for $10 or $15. The span of electrical range for all GM gauges used in the GTO series of cars since 1965 & in the Pontiac full size cars since 1967 is zero to 90 ohms.

On an oil pressure unit in a GTO with factory rally gauges in the dash when there is zero lbs of pressure at the oil filter fitting takeoff it is just as if the dark blue wire was touching engine block ground. As the pressure builds, (after you start your engine) the sender creates more electrical resistance between the dark blue wire & ground. There are 2 types of modern oil pressure sending units, (make sure you get the right one for your gauge). One will read to a dial which is marked Zero-30-60. The other is designed to read to a dial that is marked: Zero-40-80.

As the pressure builds inside the sender the electrical pathway relative to engine block ground changes, gradually adding more & more resistance to the dark blue wire. On a zero-30-60 gauge the ohms are: zero=zero ohms, 1/2 scale (30PSI=45 ohms) 60PSI= 90 ohms.

On a gauge with a zero-40-80 dial, zero=zero ohms, 1/2 scale(40 PSI=45 ohms), & max reading of; 80PSI= 90 ohms. NOTE: All of these tests, except for zero are +-3 to 5% variance in your actual ohm reading; as that was the standard of the day for factory GM in-dash gauges.

66 GTO 0-30-60 dial, sending unit is Carquest PS-154
67 GTO 0-40-80 dial, sending unit is Carquest PS-155

Peter Serio 8-10-2012

Great information, thanks

Testing an old Oil Pressure Sender for a car with Factory Gauges

I made this little adapter set-up from pieces I bought at Lowe's Home Improvement center, as I recall, for around $10 or $15. (I may have had parts of it laying around here already.)

Basically any old used oil pressure sender can be tested and should be before you put it back on your car. I used air pressure to simulate the oil pressure and then measured the results with my ohmmeter.

Old senders for a car with factory gauges are prone to failure. They will go bad usually in 1 of 2 ways. Either the rubber diaphragm stress cracks and/or ruptures and then it will leak oil. That or the variable electrical resistance cam and wiper assembly will simply wear out and fall apart. In some cases it will go "open circuit" In another failure it simply has a reading which is way off (in ohms) from what it should be at a given pressure.

How close does the carquest oil senders look to the originals?

Oil Pressure Sender

Quote:

Originally Posted by g68mike (Post 5119823)

How close does the carquest oil senders look to the originals?

Night and Day.