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Discussion Starter · #1 ·
I know there are a lot of topics already on this, but I seem to have a slightly different problem.
I have recently got myself a 1.8LX Mondeo 1995 and found that the temperature gauge was giving me very very low readings. After the engine had warmed up, the gauge would only move a millimetre or 2 from the off position. After reading various posts, I decided to change the thermostat and gauge sender unit (both with Ford units). Now when up to temperature the needle gets to the ‘[’ before the word Normal.
Is this likely to be another faulty sender unit or a problem with the gauge? Also is there a simple was to test either unit?

Thanks, David
 

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Big Megger
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Apparently no two gauges give the same reading from what I hear, something to do with manufacturing tolerances...

I have to change mine this weekend, will report back if it makes any difference. Currently, my gauge languishes at the far left and does nothing...
 

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MEG Corporal
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Was it a third party thermostat? Not ford?

3rd party open at 88 deg, ford at 92 deg.

You can test your temp senders (there are two by the way, one for the ECU, and one for the gauge - did you change the correct one?) by measuring their resistance.

See my website, I think I put some info on there about what changing each one will do.

www.jimmycricket.com

James
 

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Big Megger
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Excellent site you have there mate, very informaive :)
 

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Discussion Starter · #5 ·
The original thermostat wasn’t a ford one, the one I put back in was (This would probably explain the slightly higher reading). The sender unit I changed was the one located on the lower side of the thermostat housing (I’m assuming this was the correct one?) The Ford dealer I went to didn’t stock the other sensor.

I am now starting to think that it’s the gauge itself that’s faulty, as I’m getting roughly the same reading with both sensors (if I change the correct one :whistling: ). How would I go about testing the gauge, would it be just a case of grounding one of the wires? If so which one?

Thanks for the help.
 

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MEG Corporal
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The one on the top of the thermostat housing is for the ECU (this is the important one really, it controls fuelling and the cooling fan).

The gauage sender is in the side of the cylinder block, under the thermostat housing.

Ecu sender -

@ -40degC = 860 to 900 Kohms
@ 20degC = 35 to 40 Kohms
@ 100degC = 1.9 to 2.5 Kohms

I cannot find any data for the temp gauge sender - sorry.
 

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Discussion Starter · #8 ·
Thanks for the info. I’ve tested the gauge with a pot and it seems to read “normal” at only 60 ohm. Not sure if that’s correct or not. I’ve let the car run till the fan kicks in and the gauge read “R” in normal.
My question is, when the key if first turned, where will your gauge read when the engine is off, or first started? Mine will sit about a centimetre to the left of the scale. In my opinion I think there must be a fault with the dash. Is there a regulator behind there and how easy is it to change. Failing that, I may just stick a 100 ohm resister in series with the sender unit.

Any suggestions?
 

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when i drive my car on long distance or short,my temp is always showing far left.its thesame when i turn the heater on and put it on hot.but if i sit in traffic,say like rush hour.the gauge moves and the fan kicks in.is there alot of faulty thermos about.not had chance to read the other posts on this. :L
 

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MEG Corporal
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My gauge, stone cold, sits the same as yours - about a cm below the scale.

Warms up in 2 miles to just leave the white area, sits almost dead centre at 40 mph, and drops a little at 70mph. Fan cuts in at the middle of the M, and takes it back down to the middle of the R.

Hope that helps
 

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Discussion Starter · #12 ·
That’s just what mine does. The only way the temperature will rise is if you sit with the engine running for 10 minutes. Think I’m going to start looking for a new dash. Do you know where you can get them pre moded with blue lights?
 
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