ROB87GTA

just recently i noticed my gta was running cool even in traffic
then i realised that my fans were on all the time .
what could cause this ? it wasn't always the case.
i have removed the cat,a.i.r. pipes,a/c and the charcoal cannister
would any of these make the fans run all the time?
also they only run when the engine is running,

thanks in advance :hail:

dale davidson

i'm not sure about the mechanical side of the equation but as far as the electronics are conserened, i'm thinking that there could be a ground in the switch wire that energizes the relay(s). the other thing i'm thinking is the switch wire from the ac , i think that that is controlled by the computer when the ac is on.

MdFormula350

I had a similar problem on my 350 tpi dual fans. The passengers side fan would come on right when i would turn the key to start the car. After doing some testing with my father we found out that the fan switch on the block was burnt up, so i replaced the bad wire connector and put in a new fan switch in. Now it works right. That is weird how both fans come on for you though, someone might of grounded both relays to make them do that. Because the drivers fan is controlled by the computer using the temperature sending unit.

ROB87GTA

thanks for the replies guys

i found the problem, there's an electrical sensor in one

of the aircon pipes that must control the fans aswell

i have stripped out all the a/c ,but had to put one bit

of pipe back with the said sensor and it all works ok again.

TunedPort350

I dont know what connector you are talking about, but you might have a wire which is shorting to ground, and when you move the connector which you plugged in it moved that wire as well. You also might have one of the two secondary fan switches acting up on you.

If you have dual electric fans then the primary fan is controlled by the ecm. The secondary fan comes on when either the ac switch turns it on, or the coolant switch in the head turns it on. Consequently when the secondary fan gets a ground from either one of these two switches it ALSO grounds an input to the ecm which is "Fan Request". So the ecm does not control the secondary fan, but it does know when it is turned on and if the primary fan is not running when the "Fan Request" input comes on, then the ecm will turn it on.

I know (and hope of course) that you said you fixed the problem, but just keep this in mind if it mysteriously starts acting up again. I had a similar intermittant problem which ended up being a short in the wire which went to the coolant fan switch in the head.


EDIT:

Sorry, I just re-read your post and realized that you meant the air conditioning tube (I was thiking of the A.I.R. system for emissions). Yes, that is the switch which I was referring to above. You can just leave the switched plugged in like you said. You don't really need the tube, but you must ground the switch if you remove it (the tube).

ROB87GTA

Thanks for the reply TunedPort350

when you say ground the sensor wire do you mean i could

just put a piece of wire across the terminals of the connector

and then remove the last bit of pipe with the sensor in.