Coolant fans diagnostic.

[femurphy77]

I'm currently troubleshooting the non-running coolant fans on my '92 LT1. They are not turning on at the prescribed temps. The fans work when I hotwire them so I know they are not at fault. A previous owner had "hotwired" the coolant fans to run whenever the interior fan is turned on. Looking through the service manual the troubleshooting chart says to ground the diagnost test terminal which should turn on both fans. My questions is where is this diagnostic test terminal that they are talking about? I don't think they are talking about the ALDL terminal under the dash. Are there any other test terminals on the car that I don't know about? Thanks in advance, Frank Murphy, Indy

 

[C4CRAZY787]

Yes it’s the ALDL, when you ground the one of the pin’s (can't remember which one) then turn the key on, the fans will come on, I remember this because I didn't expect it and thought I did something wrong. If they don't come on it probably the relay/'s, there on the rad. shroud by the hood support. Hope this helps, Good Luck...