Hey guys, 1990 F-150 302ci 5 spd 4x4

i recieved alot of help on my "I cant figure this out" post, i appreciate it.....now for another problem, maybe related........the coolant temp gauge does not work, the previous owner had said it worked fine until his mechanic changed the water pump, i found 1 the temp sensor prongs broken, so figured cool......so i changed the temp sensor, still no help, the fuse is good........now i havent checked for continuity on the wires yet, but seems wierd that when the water pump was changed the gauge stopped working, and the previous owner said it stopped working that day he said he is 100% sure of that, any ideas??

Thanx in advance,

Eric

 

In the old days, I would ground the wire to the block and see if the gauge started moving in the HOT direction. I don't know if the same idea applies on today's truck, but if the gauge moved, the sensor was bad. If the gauge did not move, wiring or gauge were faulty.

Do not leave the wire grounded for an extended period of time as you may damage the gauge.

Now may be the time to mount a "real" water temp gauge. Search for "real" oil pressure gauge; there is a how-to on that one that you may find useful.

Good luck!

 

when all else fails....go mechanical...no more guessing...zap!

 

Unplug the connector and put a jumper wire between the two wires and it should drive the gauge full hot. If it does then you have a faulty sender. If it doesn't, like mine didn't, then you most likely have a faulty gauge. I replaced the gauge and it fixed it on mine. This was on my 95 f-150 when I had it.

Dennis

 

did you ever resolve the no heat problem? Ford makes a reverse rotation water pump for some models because the accesories and serpentine belt routing turn the pump backwards.

possibly the wires to the sending unit/connector is broken

 

for whatever reason the heat all the sudden works.i am thinking i mighta had some crap in there or something........drove it 205 miles yesterday all highway around 65-70 and it ran like a dream.......the coolant gauge i havent looked into yet.......getting the race car ready is taking alot of my time...........

Eric

 

The temp gauge sender is just to the right of the distributor with a single wire lead on it, not the one under the throttlebody.


Robbie

 

thanx, what is the screw in sensor under the throttle body?, thats got 2 wires on it, a green and black i think

Thanx, Eric