Fans & Temp

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Sep 13, 2016 | 12:54 PM

CT54531

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Fans & Temp

At what temp should the fans come on on my 1987 C4. I've owned it since new and in the past, it seems to me they kicked in in the mid 220's and stayed on till the temp was down to the low 200's or below. Now, they're coming on at 230 and staying on till the temp gets down to about 224-226, then off, then back on at 230. Fan and fan relay both work. Thermostat? Coolant sensor?

Sep 13, 2016 | 02:30 PM

antfarmer2

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My 94 comes on at 228 and 238. Have you pulled the radiator and give it and the ac coils a good cleaning? Is that by the analog temp?

Last edited by antfarmer2; Sep 13, 2016 at 02:31 PM.

Sep 13, 2016 | 02:35 PM

WVZR-1

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Quote:

Originally Posted by CT54531

These temps are from a "scanner" or you're just interpreting the temps from the IP CLUSTER display? The IP is from a different sender/sensor than that used by the ECM to control the fans and other ECM controlled functions that rely on temp.

Actually the fan behind the radiator is ECM controlled - you said "they're" hinting that you have an AUX forward of the condenser and that is actually controlled by a switch and NOT controlled by the ECM. Which fan(s) are you mentioning?

Last edited by WVZR-1; Sep 13, 2016 at 02:35 PM.

Sep 13, 2016 | 04:47 PM

Tom400CFI

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From: Park City Utah

Quote:

Originally Posted by antfarmer2

Is that by the analog temp?

'87 = all digital. No Analog gauges.

Sep 13, 2016 | 05:09 PM

CT54531

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Quote:

Originally Posted by antfarmer2

My 94 comes on at 228 and 238. Have you pulled the radiator and give it and the ac coils a good cleaning? Is that by the analog temp?

New radiator. All seems in order with that. And did clean the AC coils in the process. Mostly, it just seemed to me to be different than before.

To WVZR1: I'm referring to the display temps. And the "they" was a slip of the tongue having recently worked on my wife's Elantra.

I've occasionally seen references to "resetting" the temp for the fans. Being somewhat committed to the "if it ain't broke, don't fix it" school of thought, is that something to consider/

Thanks for the replies.

Sep 13, 2016 | 09:27 PM

WVZR-1

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Have the car scanned and check the CTS (ECM) values - you could compare the CTS values to the IP values but don't expect a match, close maybe but no match.

Sep 14, 2016 | 03:13 AM

Cliff Harris

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From: Anaheim CA

Quote:

Originally Posted by antfarmer2

My 94 comes on at 228 and 238.

Those are the standard "fan on" temperatures. I don't know offhand what the turnoff temperatures are.

The main fan is controlled by the ECM. The auxiliary fan is controlled by a coolant temperature switch in the driver's side head between spark plugs #1 and #3.