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Chris (aka- Moose)
Chris (aka- Moose), Technician
Category: Ford
Satisfied Customers: 47687
Experience:  16 years experience
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I have a 2001 crown vic. The analogue coolant temp gauge

Customer Question

Hi,
I have a 2001 crown vic. The analogue coolant temp gauge does not come off the low peg with the engine at operating temperature. The coolant temp sending unit has been changed and the cylinder head temp sending unit has been changed. There are no active engine codes that I can retrieve. The electric fans run almost continuously and come on at initial start with the engine cold. any ideas. so far I have not rung out the wires because I don't have a good wire diagram.
Any ideas?
Kevin
Submitted: 1 year ago.
Category: Ford
Expert:  Chris (aka- Moose) replied 1 year ago.

Welcome, I'm Chris (aka Moose) I'm an independent contractor here at Just Answer.

I do have the wire diagram if its needed?

Does your scan tool have the ability to see what the PCM shows for coolant temp?

Thanks for asking your question and letting me try to help you.

You should see a rating screen if I have posted an answer, not for an info request.

Your rating is my feedback. If I don't get feedback from customers, I will not be able to continue helping customers here.

Rating me good, bad, or not rating at all does not effect the fee you have paid nor does it close the post.

Follow up/Reply as many times as needed.

Customer: replied 1 year ago.
No. I just have a basic Actron CP9125 that only reads codes.
Expert:  Chris (aka- Moose) replied 1 year ago.

Disconnect the engine coolant temperature sender and install a jumper wire between the Red/White wire and the Pink/Orange wire on the sending unit connection. This should result in the gauge pegging past Hot. Is that the result you get? if not then wiring is for sure the next step to check.

Customer: replied 1 year ago.
I'll try it when I get home from work today. Thanks
Expert:  Chris (aka- Moose) replied 1 year ago.

Thanks

Customer: replied 1 year ago.
Hey moose,I jumpered the connector. The temp gauge pegged to the max indication. I shot gunned another ECT sender, plugged in the connector (I knew you were gona ask me that) and let the car warm up. Still pegged full minimum indication.Kevin
Expert:  Chris (aka- Moose) replied 1 year ago.

That test indicates the wiring and gauge are fine and you have ruled out the sensor. Are you sure it is not running to cold from a stuck open thermostat?

Customer: replied 1 year ago.
No not positive but the car was cold when I started it tonight. I let it run until the upper radiator hose started to warm up. I could feel when the thermostat opened. Its my friends car. He spent a bunch of money at a shop and it still has some issues. They replaced the intake manifold and crossover tube. I am assuming they replaced the thermostat and ECT sender but that's why I replaced the ECT to make sure it was good. The temp gauge didn't work when he took it in and I just finished a timing set and A/C pump. I'm trying to get the indicator working before give it back to him. my concern was that the gauge was bad in the cluster but did I rule that out with the jumper test?Thanks
Expert:  Chris (aka- Moose) replied 1 year ago.

Based on the gauge moving, that is Fords test to indicate the gauge does work. The ECT does not actually measure temp. It will register normal coolant temp for a wide range of actual coolant temp. The upper radiator hose should be near 200 degrees at operating temp.

Customer: replied 1 year ago.
I don't have a temp reader to measure the upper hose temp but it gets hot enough that I cant hold my hand on it for an extended period. Would that be enough to at least bring the indicator off the peg. Im also getting full heat out of the climate control. Something I think is strange that I mentioned earlier is that the electric fan comes on before I can get out of the car and under the hood and it runs continuously. It cycles off for only about 10 to 15 seconds and comes back on again.
Customer: replied 1 year ago.
Also, the A/C pump is disconnected electrically right now until I can have the refrigerant serviced. Don't know if that may affect the electric fan but I thought it might.
Expert:  Chris (aka- Moose) replied 1 year ago.

Does the cooling fan continue to run with the climate control off?

Anyway you can borrow a scan tool to get the CHT reading from the PCM?

Customer: replied 1 year ago.
I may be able to borrow a scan tool tomorrow. I've been looking to purchase one with live data but haven't had the dough. I'll go out right now and run it with the climate control off and let you know.thanks
Customer: replied 1 year ago.
Hey Moose,I started it up, the fan comes on as usual. Turned the climate control off and the fan still runs for about 2 to 3 minutes and off for 7 to 10 seconds.I'll see if I can get a scan tool tomorrow and read the coolant temp. I've heard good things about the Actron CP9580. Anything you can recommend?Kevin
Customer: replied 1 year ago.
Are you want CHT or ECT? Or both?
Expert:  Chris (aka- Moose) replied 1 year ago.

I have never used a tool other than the Ford tools when working on a Ford. The NGS, WDS, and IDS.

If you can monitor both that would help.

The cooling fan which is controlled by the PCM indicates the PCM is showing running hot or its not getting a reading either and in a preventative measure state.

Customer: replied 1 year ago.
Ok thanks. Was thinking the fan might be a piece of the puzzle. I'll see what if I can get a scanner and get those temps. Wont be able to get on it until tomorrow evening. let you know as soon as I can.Thanks,Kevin
Expert:  Chris (aka- Moose) replied 1 year ago.

Super

Customer: replied 1 year ago.
Hey Moose,I got a scan tool. Start up coolant temp was 41 F, outside air temp 41 F Inlet air temp 41 F. I didn't see an input for CHT. After warming up the car the Coolant temp settled in at 189 F, IAT 54F.Kevin
Expert:  Chris (aka- Moose) replied 1 year ago.

So that means the computer is getting an accurate reading from the ECT. The PCM uses the CHT reading for fan operation. With that ECT reading it can only mean the instrument cluster is to blame for the gauge issue.

.

Customer: replied 1 year ago.
That's a bummer. I was hoping that wouldn't be the case. However, I thought that by getting max indication with the ECT pins jumpered that it ment the cluster was good. Also why does the fan run continuously if it runs from the CHT? Is it possible to replace the coolant temp indicator in the cluster without replacing the cluster?Kevin
Expert:  Chris (aka- Moose) replied 1 year ago.

There is a resistor inside the cluster on this circuit. It appears to be bad and not allowing the gauge to settle in the normal range even though the cluster is getting a correct reading. The PCM uses the CHT reading to know how to work the fan. Your CHT reading would have to be to high to result in continual fan operation. The cluster is replaced as a whole.

Customer: replied 1 year ago.
do I have two separate issues? The CHT sender is new. Doing some reading now on repairing the temp indicator or I think I've found a company that I can send it to repair it.
Expert:  Chris (aka- Moose) replied 1 year ago.

With what you have told me yes, 2 different issues.

Customer: replied 1 year ago.
Is it possible that there is an issue in the PCM? It seems odd that they both are so closely related but completely separate issues and that the ford test to rule out a faulty indicator resulted in a good temp indicator. What can I do to test the integrity of the fan circuit in order to isolate it from the coolant temp?
Expert:  Chris (aka- Moose) replied 1 year ago.

you would need a scan tool that can access the CHT reading and monitor the cooling fan signal from the PCM.

Expert:  Chris (aka- Moose) replied 1 year ago.

I like to stay in contact with my customers that appear not pleased, still working on the concern, or have not rated yet. I assume you were not pleased with my help. I hate that you have spent money to get an answer but left not happy. Can you tell me why, or can I help more. If its more help you need just reply and we can pick up where we left off.

Thanks Chris

Customer: replied 1 year ago.
Hey Moose, its not that I'm not happy with your help. Its that after all that, Im left with no answer but to replace the cluster. But at this point Im not 100% sure that if I recommend to spend the money to do that, that it will fix the problem. Then still I have to start with a fan issue. Also its not your fault but I'm realy not happy about the fact that "just answer" keeps sending me pop ups to try to upsell me. You've been helpful but this has not been a good experience for me. not sure where to go from here.
Kevin
Expert:  Chris (aka- Moose) replied 1 year ago.

I have no control over what you get and receive on your screen outside of what I type. I do not even know what your end looks like or the emails you get. What would you like to do now, you have already paid the website to get help, though I have not been paid because of no rating. I hate to see you waste that money and leave not pleased.