[AT] STP

[Steve W.]

Just watch the OP gauge at start-up. If you fire up the engine and it 
"jumps" up to a point and stays there your looking at the fake gauge. A 
real OP gauge will rise and fall with engine rpms. Also the OP will 
differ from a cold engine to a hot engine.

Michael Miller wrote:
> Steve,
> 
> You don't know if this would apply to a '95 F-250, do you?
> 
> 
>> From: "Steve W." <falcon at telenet.net>
>> Reply-To: Antique tractor email discussion group 
>> <at at lists.antique-tractor.com>
>> To: Antique tractor email discussion group <at at lists.antique-tractor.com>
>> Subject: Re: [AT] STP
>> Date: Sun, 25 Feb 2007 22:43:41 -0500
>>
>> Phil,
>>  I hate to be the bearer of bad news but if that F-150 is between a 
>> 90-96 model you don't have an oil pressure gauge. You actually have a 
>> glorified idiot light. Ford decided that they were getting to many 
>> complaints about the oil pressure variations on there vehicles so they 
>> outfitted the 90-96 F 150, T-Bird and a couple others with gauges that 
>> don't read oil pressure, they read a resistor switched into the 
>> circuit by a switch in the sender.
>>
>> What the manual says about the infamous OIL PRESSURE GAUGE!....
>>
>> "When the engine oil pressure is normal, the oil pressure switch is 
>> closed(short circuit), allowing current flow through the 20-ohm 
>> resistor on the cluster flexible circuit into the gauge which drives 
>> the pointer to a position slightly above midscale.  The switch opens 
>> (open circuit)  when oil pressure drops to a critically low level (4.5 
>> - 7.5 psi) causing movement of the pointer to or below the "L" band."
>>
>> "NOTE: The pointer of the magnetic gauge will remain in it's last
>> position when the ignition is turned off.  It will move to the correct 
>> (or actual) indication whenever the ignition is turned back on."
>>
>> http://groups.google.com/group/rec.autos.makers.ford.explorer/browse_thread/thread/46706ab95d9f44fe?q=ford+ 
>>
>>
>> This is for the Tbird but the F is about the same.
>>
>> How to convert your oil pressure gauge
>> by Mike Maroschak
>> mmarosch at cgocable.net
>>
>> 1. Remove sender unit's wire.
>> 2. Remove oil pressure sender unit with a 1 1/16" socket or the 
>> special oil pressure sender socket (which actually works better if you 
>> have one).
>> 3. You might have to move some of the accessory belts out of your way.
>> 4. Put Teflon tape on the new sender unit's threads.
>> 5. You may have to use a 7/8" open ended wrench to **** the threaded 
>> pipe (that comes out of engine block) slightly one way or the other.
>> 6. Thread in the new sender as tightly as you can with your bare hands 
>> (as you would your oil filter). It's easier if you make sure the 
>> sender and your hands are dry and grease free.
>> 7. Re-connect sender unit's wire
>> 8. A small number of Thunderbirds have the 20 ohm resistor located on 
>> the oil sender wire approximately 5 inches form the sender itself. If 
>> this is the case, bypass or remove this resistor and skip steps 8 
>> through 14 (inclusive).
>> 9. Remove trim around instrument cluster. There are 2 screws at the 
>> top, then ease it on out.
>> 10. Remove screws around instrument cluster. Ease it out several 
>> inches, tilt the bottom out, and gently pull the 2 connectors off.
>> 11. Be careful not to scratch the instrument cluster's bezel.
>> 12. Flip it up side down and solder a piece of 18 gauge (insulated) 
>> wire in parallel to the 20 ohm resistor behind the oil pressure gauge. 
>> There is no need to remove the resistor. Be careful not to melt the 
>> plastic.
>> 13. This would be a good time to remove the bezel and clean it.
>> 14. Also a good time to replace any burnt out bulbs.
>> 15. Replace instrument cluster.
>> 16. Remember to check for leaks.
>> 18. 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
>>
>> 19. The oil sender part numbers are as follows: Standard Motor 
>> Products: PS-60 Echlin: OP6091 Motorcraft: SW-1547-B, E4ZZ-9278-A
>>

-- 
Steve W.
Near Cooperstown, New York

Pacifism - The theory that if they'd fed
Jeffrey Dahmer enough human flesh,
he'd have become a vegan.