ICRM? Running a bit warm here...

[NotSoSlowSHO]

ICRM? Running a bit warm here... :REVISITED:

'89 SHO

Will the cooling fan turn on with the defroster, even if the ICRM is at fault?

The fan turns on with the defroster, but fails to turn on without. In stop and go traffic it creaps up, until I turn the defroster on.

ECT and T-stat are less than 10k old.

 

[AutoSHO]

Classic bad ECT symptoms. If the Relay was bad the fan would not turn on period.

 

[NotSoSlowSHO]

WTF? Thats what I originally thought.

But I JUST changed out the ECT this morning...
The T-stat has 10k on it.

Does the computer need to be reset?
Could the harness be bad?

 

[AutoSHO]

It could be the harness or the computer. I would try swapping the computer first, its easier. you can also check continuity in the circuit from the ECT to the computer, pin 7 on the EEC plug (Lt Green/Red).

 

[NotSoSlowSHO]

thanks for the quick replies.

Ill pull out the multimeter tonight.

Real quick... what computer does the '89 have? I do not have another to swap with it, do I need the same type?

Thanks

 

[projectSHO89]

NotSoSlowSHO:
'89 SHO

In stop and go traffic it creaps up, until I turn the defroster on.

Creeps up to what indicated temperature?

Have you measured the operating temperature with an independent measuring device to verify that the guage is giving an true indication of operating temperature?

It is completely normal for the temperature to rise while the car is not moving as in stop and go driving. The question that has to be asked is whether the rise is too great and only a real measurement will tell you that. I would not worry about it unless you are hitting into or almost into the RED range of the guage.

I would not expend any money or time is swapping out parts until you have an accurate understanding of how the system is supposed to operate and you understand how yours is deviating from that proper range.

Steve

 

[NotSoSlowSHO]

I have a real water temp gauge on it.

With the defroster on, in stop and go traffic, it stays right at 195.

Without the defroster, it has gotten as hot at 220+, as indicated on the gauge. The first time it happened, I didnt notice it until it was nearly at 230. nono

 

[Off Road SHO]

I think you might have an air flow problem. Your radiator is not getting enough air through it to do its' job. I know it's difficult to see between the radiator and AC coil, but check to see if there is any debris on either component.

Tom

 

[AutoSHO]

I doubt it is a flow problem since the fan is not turning on. If the fan is not kicking on at 215 degrees, then either the ECT is bad, the ECU is not reading the ECT correctly, the ECU is not triggering the signal wire to the Relay module, or the wiring between the ECU and the Relay module is bad.

 

[NotSoSlowSHO]

okay, now I am even more confused.

I tried to trouble shoot the problem this evening... but it is hard to troubleshoot, when there is no trouble madflame

all was fine tonight.

First, I checked continuity from the ECT housing, to the bolck. okay.
Then I checked continuity from the sender to the EEC. okay. (major PITA removing the EEC by the way )
Then i fire her up, and get her warm. I covered the grille, and closed the hood to aid warming up. Idling in my driveway it took a while... but at just about 215, the fan turns on, then off a minute later.

So, totally confused, I shut her down and pull codes.

all okay. oh

So, what could give random issues like this? Besides a look connection?

The ECT is working, and is getting a signal to the EEC (possibly only sometimes), and the EEC is triggering the fan (possibly only sometimes)

Where do I go from here? shrug

 

[AutoSHO]

Drive it off a cliff?

You'll probably have to wait for the problem to show up again. It could be that removing and reinstalling the EEC cleaned up the connection on it enough that it works now, whereas perhaps before it was fouled.

 

[NotSoSlowSHO]

AutoSHO:
Drive it off a cliff?

finger

 

[AutoSHO]

I guess I can't talk. I was ready to drive mine off a cliff last week, and what does it look like now?

 

[NotSoSlowSHO]

Update

:UPDATED:

Back to it again.

Lately the c'ooling issue had gotten MUCH worse. If I stopped for more than 5 minutes, and let the engine idle, the temp would just creep, and creep... No fan whatsoever.

This evening I dove into it again. Trouble shot it properly.

Turns out that the fan WAS getting power when it was supposed too. But no fan

SO, I tore the motor apart:

Brushes help!
Two of them are completely used up