high oil pressure and coolant temp.

[asp84]

Hey,
After converting a 94 EXPLORER 4.0L V6 in my 90 Ranger I got a couple questions. Why does the Oil Pressure gauge ride Over the L on normal? (indicating high oil pressure, even after a fresh 5qt oil change) Also the Coolant temp is running high even after flushing the system and replacing the thermostat. The coolant temp needle is on the A on Normal and when the AC is on, it moves above the L of normal. What can I do to diagnose and fix these problems?

(The whole engine compartment, wiring, dash and instrument panel, is from a 94 explorer.)
Thanks,
Al
asp84@earthlink.net

 

[asp84]

The coolant stays below the normal for about 4 minutes and then dramatically jumps to the A on normal. (when I first start the car)

 

[Maniak]

I might have an answer for the oil pressure issue. The Oil pressure guage on First Generation explorers is actually just an analog idiot light. If there is more than 5psi it shows normall.. if not.. it doesn't read.

We converted our analog idiot light to a real guage (you just short out a 200 ohm resister on the guage and change the sending unit)

I converted the guage before I changed the sending unit. When I had the Ford Explorer sending unit in the engine with the converted guage it read practically off the scale (high). Once I put in a real sending unit it was back to normal..

The "Real" sending unit is much bigger than the one for the analog idiot light. Here are a few part numbers for the real guage.
Niehoff p/n is FF133E
SMP: PS-60
GEN: OP24761