I have a 1990 Ford F150 with 5.0 A/T. I am looking for the Oil Pressure sending unit / switch (my truck has the oil pressure gauge on the dash) . I know it should be in the block but I can't locate. My Haynes manual does not have a listing for it. Does anyone know where it is or a website with a picture or illustration of it? Thanks

 

It's a 6psi switch, and it's behind the PS pump in front of the filter pointing straight L with a single Wh/R wire & a 90-degree rubber-coated connector. It's not labelled in this diagram, but you can see the boss directly L from circle #9.



But it's really easy to swap it for the older-style pressure SENDER (with some cheap plumbing to space it out from the block), solder a jumper wire across the resistor on the back of the instrument cluster, & have the gauge really work.

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Steve83,

Does the photos also apply to the cluster on 87-91 Ford trucks? I already ahve the sender and the extension that were used on older Ford engines already. If this is as simple as the 92-96 I'm doing it the next morning....

 

Basically, yes. Just make sure you jumper the correct resistor by following its trace from the oil pressure gauge terminal.

Another cool mod that would require a little more effort for '87-91 is adding a low fuel light. Click my signature link & look in that album. If you understand basic 12V wiring, it's easy to adapt the procedure to your truck.

For anyone reading along with a pre-'87: forget about the low fuel light. The older in-tank level sender isn't compatible.

 

I'm not worried so much about the low fuel light. I constnatly watch the gauge as it like to gulp Amoco 89

When you say put a jumper across the resistor, can it be any type of small gauge wire as long as it jumps that resistor? Got the cluster out of the truck (first time it has been removed since being built) and found the resistor.

 

Didn't you look at the color photos in post #2? Yes, any wire at least as heavy as the film circuit traces is fine.

 

Took a second look and saw the jumper. Done the mod this morning and put the cluster back in (supposed to rain/sleet/snow tonight and it does make a big difference Now to do a 3G alternator conversion and the electrical will be done...