I'm hoping someone can offer a suggestion for an erratic water temperature gauge for my 95 Lightning. It either works fine or it is driven way to the left of the "cold" mark. The water/antifreeze level is correct and the thermostat is new. This problem has progressively worsened. In other words, it is not as intermittent as it was. It doesn't indicate a reading anymore other than the slam to the left side of the gauge. Any thoughts would be very helpful and appreciated.

Thank You,

Gary Sloan

 

Have you checked the sender?

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2000 F-150 XL,RC,LB,5.4,4R70W,3.55LS,
Class III tow/Payload #3/Convenience pkgs.,
4-wheel disc/ABS,Chestnut/Parchment 40/60,
Ford bedliner & gas/wheel/spare locks,
3" cold air box modification,Superchip,
Dynomax ultra-flow welded 3" cat-back.

 

The sender...where exactly is that located? And how would I go about testing it?

Thanks,

Gary Sloan

 

It is threaded into the intake manifold coolant passage. Checking it requires measuring the current change compared to temperature change. If not familiar with this just try replacing it. They are not expensive. If it is OK, try check the sender and gauge wiring, grounding, etc.

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2000 F150 XLT 5.4 7700 Payload
K&N FIPK Superchip Dynomax Cat Back

 

That would be my first guess too...

I have heard of something similar on a different site, I think the problem was being caused by a ground that wasn't properly grounded.

The temp sensor is I believe the largest sensor on the driver's side intake manifold(lower)...I believe it's between the #5 and #6 cylinder.


You can tell if the sender is bad, by first disconnecting the wire, switch on the ignition, no start-the guage pointer should be at the cold mark. Using a jumper wire, ground the sending unit wire. The needle on the guage should now be pointing to (or past) the hot mark. Also, don't live the jumper connected any longer than you need to.

To replace the sensor, get the new one, wrap it in teflon tape, and replace it as fast as posible to prevent coolant loss. As well as a mess. The attach the wire. You might even consider resetting the computer, although it probably isn't neccessary.

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toydestroyer1@yahoo.com

"Sleeper"


1993 F-150 302/e4od/355 Limited slip. dual exhuast w/o mufflers, 2 1/4" pipes, Echo Tips, Summit Racing headers, MSd Wires/Motorcraft Plugs, hypertech powermodule, 4 degree advance,Blaster Coil,MSd 6A Ignition, TPS Mod,5% dark tint, Ford Bed mat, Bundy Chrome Drop bumper, Wrap-around bug deflector, 2-tone tan/brown. Alpine cd player and Pioneer speakers, with tweeters No room for anything else.

1989 F-150 XLT 4x4 302/Aod MM hubs, true duals with turbo mufflers, maroon/grey middle, est 200hp

 

Gary, This is DEJAVOOOOO I have a '96 150
and have been living with this the last year.

Check my post in the engines forum that I posted just last night.

I already changed the "SENDER", it's not easy to get to and I still have the problem. On the ALLDATA.COM web site I found a gauge diagnostic sheet. See if you have the same condition. The sheet says that there should be 10-15 volts at the SENSOR located on the thermostat housing. I only have "3" Volts.
I also only have "3" volts at the "SENDOR" wire to ground

Just so you and I have the same problem....
with the ignition off the needle parks on the "C"....as soon as the ignition is turned on it immediatly pins below the "C" and stays there no matter how hot the engine gets?

If you figue it out PLEEEeeeeeeeese pleeeeese
pleeeeeese let me know.....
Thanks, jimbello@bellatlantic.net

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Gary Sloan,
Thanks to some help from Pastmaster I was able to get this info from ford-trucks.com
Below I cut and pasted a response to a problem someone had with a ranger.

There was another response from someone mentioning the IVR circit for the gauges but in that case all the persons gauges were screwy, and not just the temp gauge.

I already priced the gauge and for my 150 it's a oil and temp combo so both have to be bought at the same time.....
I'm considering a trial and error fix method but at $100 for the gauges I'm still thinking about doing more voltage and grounding checks

Back on July 30th I asked for help on a problem that sounds a little like this except on a used
F150 Lightning I bought. In my case the guage goes high for a short time then drops back to the
low normal range after starting the engine.

First noticed this when the engine was cold, so I replaced the thermostate thinking it was sticking.
Did not fix the problem and then noticed that it did the same thing if started hot. By the way, the
engine shows no evidence of ever actually running hot.

Got no response from this forum, however, on one of the other internet truck sites at this point a
long time Ford mechanic agreed with me that it must be the sensor. Replaced the sensor with no
improvement. Another Ford mechanic on that forum said he had seen these types of problems
before and it was more likely an internal ground in the guage itself. Have not had time to check the
guage out yet, but he said variations of what I have often are caused by a faulty guage.

Charla

 

Update on the original post. I disconnect the wire attached to the sender and switched the ignition to the "on" position. The water temp gauge immediately slammed hard left. I then grounded the wire (expecting it to indicate "hot". Nothing happened. This leads me to believe it is more a problem of the gauge itself. Now what? Any suggestions?

Thanks in Advance!

Gary Sloan

 

Gary Sloan,

IT'S THE GAUGE!!!

I bit the bullet and bought the gauge assy. and all is fine.

 

Hey Jim, I have a question for you...When you say you bought the assembly, do you mean the whole cluster, speedo and all? How did you order it? Did you order it through Ford? or did you get one from a part yard? If you replace the entire cluster, you'll have to remember that the odometer reading will be different, you might like this or this may be a pain. You can replace the little unit that remembers the readings, it is on the cluster itself. The computer doesn't recall the reading.

 

No, I didn't change the entire cluster...
Thought about it but at close to $800 I flattly refused....I'd do without the temp gauge at that price.

I called a ford dealer and asked about the availability of the gauge and was told that the temp and oil gauges come as an assembly.

I ordered it and it was in in two days. It took about 2hours to change it and I must say it was very easy. I used to be a chevy man at one time and I remember what a nightmare GM vehicles were to work on but Ford....A dream.

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96 F150 XL,special
Air/PS/PB/AM-FM-Cass/
Light Package/300 I6/
5 SP Man/...
Nothing fancy just my little baby

 

I have a 93 lightnin with a inop coolant gauge, I have replaced the sender and have checked the guage, the wire leaving the sender, sound I be able to read any conection to gound?