Fans not coming on?
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
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Fans not coming on? Just picked up a Trans am and I've barely driven it till today. After being driven for a minute then sitting in park the temp. slowly goes up to almost 210. Then I checked and fans don't come on but they come on when I have the AC on?
The fans are controlled by the PCM, but the trigger temperatures vary by vintage/model.
https://ls1tech.com/forums/general-m...-help-plz.html
https://ls1tech.com/forums/general-m...-help-plz.html
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
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The fans are controlled by the PCM, but the trigger temperatures vary by vintage/model.
https://ls1tech.com/forums/general-m...-help-plz.html
https://ls1tech.com/forums/general-m...-help-plz.html
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Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
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That's what I was thinking. Then I went to that link I was just sent and it said the fans on his 02 Corvette don't come on until 220 degrees? I know it's a different car but could that be how my pcm is set up? I thought my thermostat was 180 degree?
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Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
Likes: 0
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
Likes: 0
IMO, it still wouldn't hurt to have the fans set to come on at a lower temperature.
An easy way to check the relays is to (first mark them,1/2/3) swap them around and see if it runs cooler, or hotter. If it does change the temperature then you know you have a issue with one of the relays.
Last edited by 99Bluz28; Apr 27, 2014 at 01:28 AM.
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
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Well if it doesn't go any higher than that, yeah I guess you'll be fine.
IMO, it still wouldn't hurt to have the fans set to come on at a lower temperature.
An easy way to check the relays is to (first mark them,1/2/3) swap them around and see if it runs cooler, or hotter. If it does change the temperature then you know you have a issue with one of the relays.
IMO, it still wouldn't hurt to have the fans set to come on at a lower temperature.
An easy way to check the relays is to (first mark them,1/2/3) swap them around and see if it runs cooler, or hotter. If it does change the temperature then you know you have a issue with one of the relays.
you have a bad relay,
Im not a ele guy But changed out my stock 2 fans and shroud for one spal fan for weight
I had some trouble wiring it, and learned a little about the fan ele. And found out since I bought my cars years ago my 2nd fan wasn't even working (noticed it had alot more dust and bugs on it from not working for a long time) and I had a bad relay. The PCM turns them on by grounded them in the relay. I think the fans or the relay ( 1 and 2) always has power, the pcm triggers the ground, thats what turn them on. My fan 2 wouldnt turn on but the fan plug whould get 12v when it got up to temp. But when you plug it into the fan (put a load on the circet) it would loose the 12v (relay dumped it?) took a while to figure it out.
,
There is 3 settings (fan 1 on, fan 2 on, fans,and both on high (AC on) and only 2 fans, so you have the 3 relays to do it.
Find a another thing in your car that has the same relay, (air pump, ac,somthing) pull that out, Mark your fan 1,2,3 relays so you remeber what one was bad when you check them. Get the car up to temp (AC off) and one at he time change the fan relay 1, 2 and 3 with the other good relay. hopfully the fan 1 turns one like normal, and that was the bad relay.
also check the fuses, and the wiring for damage and that the fans turn free and smooth. sure you did that 1st
Im not a ele guy But changed out my stock 2 fans and shroud for one spal fan for weight
I had some trouble wiring it, and learned a little about the fan ele. And found out since I bought my cars years ago my 2nd fan wasn't even working (noticed it had alot more dust and bugs on it from not working for a long time) and I had a bad relay. The PCM turns them on by grounded them in the relay. I think the fans or the relay ( 1 and 2) always has power, the pcm triggers the ground, thats what turn them on. My fan 2 wouldnt turn on but the fan plug whould get 12v when it got up to temp. But when you plug it into the fan (put a load on the circet) it would loose the 12v (relay dumped it?) took a while to figure it out.
,
There is 3 settings (fan 1 on, fan 2 on, fans,and both on high (AC on) and only 2 fans, so you have the 3 relays to do it.
Find a another thing in your car that has the same relay, (air pump, ac,somthing) pull that out, Mark your fan 1,2,3 relays so you remeber what one was bad when you check them. Get the car up to temp (AC off) and one at he time change the fan relay 1, 2 and 3 with the other good relay. hopfully the fan 1 turns one like normal, and that was the bad relay.
also check the fuses, and the wiring for damage and that the fans turn free and smooth. sure you did that 1st
Last edited by studderin; Apr 27, 2014 at 08:31 AM.
Thread Starter
Staging Lane
Joined: Mar 2014
Posts: 93
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Drove the car to work today and the cooling was good it stayed at 180 unless I was at a stop light then it went up a little but not much but I did notice my oil pressure was low... But it stayed at 40 when I was driving but at idle it was low?
It's been so long since I've had my fans set to turn on/off at the factory temperatures I forgot how high they're set.
Here's the factory settings:
•Fan 1 on: 226F
•Fan 1 off: 217F
•Fan 2 on: 235F
•Fan 2 off: 226F
Here's the factory settings:
•Fan 1 on: 226F
•Fan 1 off: 217F
•Fan 2 on: 235F
•Fan 2 off: 226F