ks114

Got a question. I have a 1979 L-82 4 speed with a/c. The electric fan runs whenever it is running, regardless of temperature. Is this normal?

Big2Bird

The a/c blower? Yes, that's called flow-thru ventilation. Ralph Nader

7t9l82

It should run when the a/c is running or when the temperature gets too high

ks114

Its the electric radiator fan. It runs when the key is on.

Big2Bird

On an 81, there is a thermal switch on the passenger side head. It operates the fan. I "assume" 79 is the same. It should only operate at 230* or so. Unplug it and see if it goes off.

Bloodzone

79s still had clutch fans. Sounds like someone upgraded to electric and didn't wire it correctly. If so, I would get the wiring check asap. Might just need a fan control wiring kit.

speedreed8

79'L82./wAC Had an OEM aux. electric fan mounted in the shroud in front of the clutch fan. Should. Be a blue &black wire to a sensor in the passenger side cylinder head.

Bloodzone

Thanks. I didn't know that.

Easy Mike

No. Check the sending unit at the rear of the passenger's side head.

NewbVetteGuy

Yep- What he said. Both clutch fan and electric fan.


Mine runs from time to time, I thought it was purely temperature driven; I never checked to see if it turns on as soon as I turn the AC on or not. I can test later this week and repost back here. (If it does, I'd expect that it runs when defrost is selected too.)


Adam

SwampeastMike

The auxiliary fan operates only on temperature--on at 238F and off at 201F--this operation is regardless of the HVAC mode setting. Also, A/C doesn't operate in the "DEFROST" position in warmer weather like in modern cars.\\

From what I've read here and elsewhere during normal operation the only time the electric fan should come on is with extended idling or low speed operation during hot weather with the A/C on. But again--it's not the HVAC mode selector that turn the fan on/of--only temperature. '79s (L82 in particular) are though hot running engines. If you notice top center of the temp gauge reads 220F instead of 200F as in other C3s and most other cars. Supposedly Chevrolet changed this after complains from '78 owners regarding the gauge being right of center during normal driving. I'm not sure what was done in '80 (perhaps the aluminum intake manifold?) but '80+ went back to 200F at top center of the temp gauge.

I know that the electric fan in my '79 L82 works but I've confirmed that it has never come on while driving. I have an Edelbrock aluminum intake manifold and true dual with no catalytic converter but otherwise it is stock with all original pollution controls functioning. Summer cruising around the point my Jimmy Carter speedo looses meaning is the only time I see temp above 220 but it seems to top out at about 230. During normal driving to include 55mph or so cruising it stays right around 200.

C3 4ME

Does anyone know if it's possible to replace the sender in the cylinder head with a different one and have the factory fan come on at a lower temp? Would love to have the fan on my 79 work at a lower temp.

Capt. Shark

When I was fighting overheat issues, I wired in a relay that powers the aux fan when the A/C is turned on. I think the original factory wiring was temp switch only.

Big2Bird

Yes. Look up Volt. They have all kinds of ranges.

terry82

http://tech.corvettecentral.com/2011...191.1493779835 it maybe the same size as what you have but maybe a different connector.https://www.bing.com/images/search?v...x=0&ajaxhist=0

ks114

Finally found the switch at Corvette Pacifica

C3 4ME

terry82, that sound like exactly what I'm looking for. I'll give them a call and see what I can find out. Thanks!