Cascade Crew

85 T/A WS6 · Posted: Sun Jun 10, 2012 7:32 pm Post subject: Aggressive Fan

Wants to go go go before decent op temp. Any ideas?
Makes the car run colder than needed

Al Hasse · Posted: Sun Jun 10, 2012 7:52 pm Post subject:

Switch in the head going bad? Mine was on almost constantly before I replaced the switch.

aaron_sK · Posted: Sun Jun 10, 2012 8:04 pm Post subject:

LB9 was ECM controlled as I remember. So I would guess bad coolant temp sensor.

If you can datalog (or know someone who can) you would be able to confirm this before purchasing parts.

chevymad · Posted: Sun Jun 10, 2012 8:41 pm Post subject:

Dont have the AC or defrost on?

Also car shouldnt run below thermostat temp, even if the fan never shuts off.

DBL_TKE · Posted: Mon Jun 11, 2012 4:59 am Post subject:

Twilightoptics · Posted: Mon Jun 11, 2012 8:11 am Post subject:

85 TPI single fan ecm controlled.

85 T/A WS6 · Posted: Mon Jun 11, 2012 2:31 pm Post subject:

AC off. Unplugged battery to try to reset, maybe I didnt leave it dead long enough...what is proper time to kill ECM memory?
I have a 170 T-Stat if I recall....

Put the second new fuel pump in, seems to work so far, was a fun weekend Sad

aaron_sK · Posted: Mon Jun 11, 2012 3:15 pm Post subject:

AFAIK there is nothing that the ECM learns that affects the fan.

Twilightoptics · Posted: Mon Jun 11, 2012 4:12 pm Post subject:

Strictly an on/off parameter threshold.

85 T/A WS6 · Posted: Tue Jun 12, 2012 6:28 am Post subject:

I have a new Hypertech switch, maybe Ill put that in, no access to data logger.

If my ECM is going out, and I replaced 2 fuel pumps as a result, I'm going to the moon. Embarassed

Twilightoptics · Posted: Tue Jun 12, 2012 8:07 am Post subject:

Ecm triggers a relay for the pump, not the pump itself.