Been wanting to try this so-called oil pressure gauge mod.
Based on Lonnie's tech article.
10mm and 7mm sockets
There are 2 senders you can choose from:
Standard Motor Products: PS-60 Echlin: OP6091
Motorcraft: SW-1547-B, E4ZZ-9278-A *I used this one
I took off the old oil pressure sender with a pair of pliers.
Wrap teflon tape, about three turns, around the thread of the new sender. The Motorcraft one came with teflon tape already on the threads. I used an adjustable wrench to snug it down.
Reattach the sender lead. Shown in red.
Now you need to locate and bypass the 20ohm resistor.
According to the original tech article, Lonnie says "A small number of Thunderbirds have the 20 ohm resistor located on the oil sender wire approximately 5 inches from the sender itself. If this is the case, bypass or remove this resistor". You're done. Skip to the end.
Incase you don't have this resistor near your sender, it will be located behind your oil gauge in the cluster.
Here's how to take the cluster off without breaking the plastic tabs:
Applies to a 94 dash. Yours may vary
Remove these three bolts - 10mm
The bottom trim panel will pull right off. There are three spring clips holding the top on
This reveals 3 more 10mm bolts: (two I had already removed)
2 phillips screws
The surround can then be pulled straight back. It's also being held on by spring clips. Bring it back enough to unhook the rear defroster plug.
Tilt the steering wheel all the way down. Carefully work the surround out. It gives a little but too much and you could crack it.
The cluster is held on by four 7mm bolts in the four corners. If you needed to take the clear plastic cover off, you would use a T15 torx bit. You don't need to take the clear cover off for this though.
The cluster has 2 wiring harness connectors. You need to move the right-hand side out first to get at the one on the right side. This will give you access to get at the one on the left side. You press the tabs on the sides in and pull.
Reverse the above to put it back together again. Just remember you are dealing with plastic here. No need to crank down on the bolts.
This is the 20ohm resistor you're looking for. You need to work quickly so you don't melt the blue plastic. Take a piece of insulated wire and wrap the legs of the resistor.
Not the greatest of soldering jobs but my butane iron was a little too hot for this job.
Start it up and check for leaks.
From the original article:
When cold: between M and top line.
When hot at speed: M
When hot in gear idle: between N and O
When hot in park: O
This article demonstrates what I have done to modify my oil pressure gauge in my car. Neither I nor TCCoA assume any responsibility if you use this article to try to modify your own car. You do so at your own risk.