aresk3b

SOLVED: Found a Lose ground cable under Intake Manifold area...

Greetings.
Ap1 2003.

AEM EMS + Modifry Water temp adapter.


My car is back on the road, and engine has been rebuilt. It has been several months without it.

Problem. Cooling fans won't shut down.
A I turn the key they will go on... Temperatures stay very low and spike a bit when the car is off.

What's trigger the fans to be on all the time?
Bad ECT? stuck thermostat?

Ideas are welcome.

windhund116

Sending-relay unit(s)?

Slowcrash_101

^ this

aresk3b

I thought about that, but fans WILL shut down when ignition is off. So I assume Relay is good and not stuck open.
Does the AP1 has a thermoswitch? ot just ect?

windhund116

Think I'm missing something here. You first stated that the fans won't turn off. Correct? Or they go on, when you turn the key --- regardless of outside temp? Either way, you need to rule-out relay/sending unit issues, I would think. Time to whip out the old DVM.

aresk3b

Sorry, I didn't mention that on my first post.
Yes, the fans will go off when the key is out.
As soon I turn on the key they will spin, even with the engine not running...

I suspect ont of the sensor to be on short (AEM won't give me CEL light)
but which one is the culprit?

windhund116

I'd first check the radiator fan relay. Believe it's under the hood, in the Fuse/Relay box --- by the battery. You can see the location, by the diagram --- under my 2007 hood (right side, middle). Prolly in a different location within the fuse-relay box, of your 2003.

See if the main switch within the relay is still switching on-&-off, wrt activation of the solenoid winding.



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aresk3b

Found something on the repair manual point to the fan switch on the radiator.

windhund116

I believe your 2003 had the switch at the bottom of the radiator. Maybe, check the relay first, before draining the coolant.

CoolGuy094

I assume you checked the setting inside the AEM for what temp the fans should turn on/off? What is that set at?

Also check your coolant temperature readout inside AEM to make sure your coolant temp values look right (i.e. near ambient temp when the engine is cold, 160F-180F when engine is warm).

If your fan on setting is set stupid low or if the signal coming from your coolant temp sensor is wacky then it could cause this. Rule out the software side first.