Second radiator fan

[mbodell]

Hi
Have an '86 Coupe.
Does anyone know what the small fan at the front of the radiator is for... I've never seen mine come on at all.
The shop manual mentions a "heavy duty fan option" in the wiring diagrams, but I don't think it's that!
Cheers
Mark

 

[Hib Halverson]

that is the auxilary or HD fan.
Typically, it only comes on when the coolant temp gets really hot.

 

[86-ZZ3]

Check to see if the sensor is connected. It's on the head near (or between) the No 1 or 3 cylinders. I think you'll only see it come on if engine temp is over 200-220F.

 

[mbodell]

Thanks for the replies.

It would appear to be the Heavy Duty Cooling Fan shown in the shop manual wiring diagram. It's shown in dotted lines as OPT V08. (I've never seen it come on although I can see a sensor wire between the plugs on the left hand head.)

The main fan never comes on when cruising. The car runs at about 88degC (190f) with airflow...
However when stopped at traffic the temp climbs up, and as per the shop manual, the fan starts at 110degC (230f), brings the temp down and stops again at 102degC (215f). These temperatures are pretty hot, but I've not been too concerned as that's what the book says is normal...

Back to the small "Heavy Duty" fan, I'm wondering if the OPT V08 listed in the wiring diagram refers to the build Service Parts Identification codes sticker under the back hatch... Mine hasn't got V08 listed (although the other numbers are like that) so perhaps that fan is provisioned but not optioned? I'm only guessing!
I'm tempted to unplug it, and run a switch so I can manually turn it on as additional cooling for those stuck in traffic times when the temperature climbs up...

I'll post a separate thread to see if anyone can shed light on deciphering the Service Parts Identification codes...

Thanks again
Mark

 

[ken mohr]

Thanks for the replies.

It would appear to be the Heavy Duty Cooling Fan shown in the shop manual wiring diagram. It's shown in dotted lines as OPT V08. (I've never seen it come on although I can see a sensor wire between the plugs on the left hand head.)

The main fan never comes on when cruising. The car runs at about 88degC (190f) with airflow...
However when stopped at traffic the temp climbs up, and as per the shop manual, the fan starts at 110degC (230f), brings the temp down and stops again at 102degC (215f). These temperatures are pretty hot, but I've not been too concerned as that's what the book says is normal...

Back to the small "Heavy Duty" fan, I'm wondering if the OPT V08 listed in the wiring diagram refers to the build Service Parts Identification codes sticker under the back hatch... Mine hasn't got V08 listed (although the other numbers are like that) so perhaps that fan is provisioned but not optioned? I'm only guessing!
I'm tempted to unplug it, and run a switch so I can manually turn it on as additional cooling for those stuck in traffic times when the temperature climbs up...

I'll post a separate thread to see if anyone can shed light on deciphering the Service Parts Identification codes...

Thanks again
Mark

You can ground the wire between 1 & 3 and the fan should turn on. That will let you know it works. I changed the temp switch between 1 & 3 to a camaro switch to turn on at 210 off at 200. I also cleaned the debree from the radiator and the fan still almost never turns on.

Advice: pull radiator and clean out leaves, wrapers, etc.
Leave others alone. Fans will run only when sitting still.

 

[GO_VETTE]

I have 1 fan. mounted between radiator & belt driven accesories.
This fan is always "ON".
The last owner removed the relays and has the fan running constantly.

I am trying to figure out, if the Vette had 2 cooling fans or 1 back in 1984.

 

[rmagee7]

look for a B4p option that is what the rpo listing is or it might be P4B i cant recall right now it operates on a standalone switch in the left head to check operation just ground the sensor wire fan should come on,the main is operated by the ECM, good system if you worry about high op temps,imgoing b4p on mine as soon as the weather gets better.also mid am.sells the switches in a lower temp setting if you want to go that way