The infamous carb cooling fan

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sk8salomon

sk8salomon

10 Year 15 Year
Joined
Apr 21, 2006
Threads
147
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2,940
Location
Chattanooga, TN
I never paid attention when my 60 was running to see if the CCF runs. I know it only is working when I turn off the key and I hear it. Just making sure it's not wired to the key switch and it is allowed to run at anytime as long as the temp sensor closes the circuit?
 
It is designed to run only in the key off position. They both work on my 40 and 60 but somewhat strangely upon ignition off they come on at different temperatures and run for different durations. No concern though, at least they work.
 
sk8salomon said:
Thanks, I was hoping to separate it from the ignition key & have it cool the carb during idle or low speed. Guess I'll get out the fsm & start reading.
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The PO of my FJ40 added a manual fan switch, and did not use a DPDT switch. He fried a diode in the fan computer. The moral of this story is that if you add a manual override switch for the fan, be sure it doesn't send 12v back through the fan computer.
 
The carb doesn't need the carb fan blowing while the engine is running. To do so will wear out the fan faster because the car vibration will play hell on the bearings while the fan is spinning.
It also won't accomplish anything.

The carb gets cooled by the fuel flowing through it when the engine is running and from the radiator fan.

The carb fan was installed on USA 2Fs as a band aid, primarily to help prevent the fuel from boiling out of the carb after shut-down due to excessive temperatures caused by the emissions equipment/manifold design.
 
Ok thx for the info but here's my issue. New TL carb that runs perfect except when it gets hot. The newly added 6-1 header is creating so much addition heat. My thoughts so far were:
1-get carb cooling fan working on separate switch
2-fab some type of heat deflector plate & bolt it to the 4 open holes left on bottom of intake
3-heat wrap exhaust header & fuel line.

Any other suggestions?
 
What sort of condition is your fan clutch in?

I have a rebuilt carb on my 2F which is also running headers. I'm in Texas and have 0 heat problems. Good fan clutch does wonders.

I can tell you now that wiring up that carb fan would be useless if you have a good fan clutch. It moves so much air, especially on the driver side of the engine bay.
 
I should have verified in the earlier post, but you are saying that the headers generate too much heat when you are at sitting at idle or when you are driving it down the road? Or when you reach operating temp?
 
I have run headers on boh my '78 FJ40 and '85 FJ60. No heat issues. In fact, after the header install and most of the smog garbage removed, the fan seemed much less important. Heat issues with the carb were non-existent, even when the fan wasn't hooked up at all.
 
klinetime574 said:
I should have verified in the earlier post, but you are saying that the headers generate too much heat when you are at sitting at idle or when you are driving it down the road? Or when you reach operating temp?
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Sitting @ idle or wheeling @ low speeds. No operating temp issues, fan runs as normal. Carb starts to run poorly
 
Cruzerman my '78 is mostly stock but with aftermarket headers. No heat issues here either even before I found another CCF and electrics for mine
 
I am reviving this thread - Need some help troubleshooting, mates. Ok.. so I am trying to get my Carb Cooling Fan to run. I rigged it up and hooked it to the battery directly, and it spins, so I know the fan itself works..

When I plug the fan into the green plug, and ground what I think is the temp sensor wire - I get nothing..

The temp sensor is no longer there, so I just have short wire that went in that general direction. That is what I am grounding to a bolt on fender. I turn the key on and off, to see if that will activate the relay, but still get nothing from the fan.

I replaced the relay under the passenger side kick panel with one I bought from a used part dealer - I was told it was in good working order, and it did look like it was in better shape than my old relay.

What am I missing?? Am I going to have to pull wiring harness out and check the whole run of wire? I do not want to do that..
 
These photos are to illustrate where I am connecting things regarding the CCF.

IMG_0336.jpg


IMG_0337.jpg
 
Rube said:
check your “dome” fuse first then make sure your m4 relay checks out ok.
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Look at @Rube giving the electrical assistance! Also, @ace7141 are you sure the temp sensor is mia? I literally just had a photo of where it is on a stick setup but deleted the pix. Maybe @Rube can add it here...
 
My temp sensor was completely burned up so I cut the connector off the harness and extended the wiring back into the cab and terminated onto a SPST toggle switch. The other side of the switch goes to ground. Now my fan works great. It comes on when the ignition is turned off and runs for 30 minutes every time. If I don't want the fan to come on, I hit the switch and turn it off. It's been like this for several years now with no issues whatsoever.

The carb fan won't help with the symptoms the OP is experiencing...rough running at idle speeds. It is only there to help with re-starting a hot engine. For that, it works surprisingly well.
 
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