Good day to you all..I have a 88 350 with dual fans...one fan is inop..the one that supposed to come on at 195 (around there)I do know that the drivers side fan comes on at 224.Wish not to hot wire fans together...etc..on a switch.Like to keep stock set-up.money is no obsticle.if I need a ECM..so be it...etc.

Willing to phone you within 50 states if ok with you..just need time that is good to call you...via e-mail of course...lololol :>) toll will be paid by ME of course(just had to clarify that)

Do know one fan is comp controlled and one is switch controlled.Need someone to take the time to go over DIAG steps to find what is the problem.

I thank you for your time

Brent

 

- Turn on your A/C.... does the fan come on? On some dual fan setups, the 2nd fan wont come on unless the A/C is on.

Also, main fan will not come on till 230 or so...not 195. Your thermostat does not even open till 195, so there is no reason for the fan to come on then.

 

Hi,

I just did this last week on my car. Diagnosed it with my GM Camaro shop manual.

First, your driver's side fan is the primary fan. The passenger side is the secondary fan. The primary fan is controlled by your ecm via grounding it to turn it on. You can check your primary fan easily via the ALDL jack under the drivers side dash close to the console. Use a piece of wire to jumper the A & B terminals. They are the upper row last two on the right side. This will flash your check engine light as well as kick the primary fan on. If the primary fan does come on, I would suspect the ground in the ecm or the ground wire running out to the fan setup. If it does not come on. Take a piece of wire and run 12 volts to the primary fan to see if it will kick on. If it does, then check the relay for the primary fan. Its next to the passenger side of the radiator on the body.

Usually either the fan motor died, the relay is bad, or as in my
case, the ecm wasn't grounding the primary fan anymore.