Carb Cooling Fan info. (1 Viewer)

[crackdpot]

Hi,

My '84 fj60 cooling fan stopped starting (or started stopping).

Direct connected with 12V leads, fan runs good.

Here's my query; where exactly is the sensor & how might I check it?
; where exactly is the relay & how might I check IT?

Had this since last fall......looking forward to growing old with it.

Thanks

 

[HntWhtTail]

Do a search lots on this topic, I believe it is on the exhaust manifod twoards the fire wall easier to see from bottom looking up. you can connect the sensor wire to ground and will run fan when engine is turned off for a set amount of time. This will let you know that relay is working. Once you find the sensor just a small push on blade tupe connector, reconnect your loose wire replace with new if need be and run it to temp then shut off. hope I got this right I am usually the one asking the question

 

[sk8salomon]

Do a search lots on this topic, I believe it is on the exhaust manifod twoards the fire wall easier to see from bottom looking up. you can connect the sensor wire to ground and will run fan when engine is turned off for a set amount of time. This will let you know that relay is working. Once you find the sensor just a small push on blade tupe connector, reconnect your loose wire replace with new if need be and run it to temp then shut off. hope I got this right I am usually the one asking the question

yup, sounds right!

 

[Heartworm]

The wire going to the little bolt on the exhaust manifold is the sensor. When it gets hot, it provides the grounding for your carb fan so that it can run. Without it, it will not run unless you ground it somewhere else, and then it will run whether you need it or not. The little wire is fragile and often gets knocked or burnt loose. When you connect the little wire, be careful that it does not touch anything besides the post and nut on the sensor, or it will be grounded all the time.

 

[crackdpot]

Hey!

Thanks for the info!

I'll do a bit 'a crawlin' an' see what I can see!

I'll be back.

 

[crackdpot]

Just fer my info, Where is the relay?

I need to get Toy shop manual.

 

[soggy60]

There's two 'relays' !

One - behind passanger side kick panel; senses copnditions at sensor,
controls another relay (that powers fan), has timing circuits etc.
All this stuff is in a black box, second up from bottom of stack.
(bottom one has , umm had, that damn little beeping thing...key & seat belt alarm)

The 'another relay' is behind drivers kick panel, little 'can' relay
actually controls (on - off) volts for fan motor. activated by 'black box' noted above.

Note : sensor between, and under, #3 #4 exhaust is not a switch, it's a resistor that changes resistance with temperature (thermister).
If the connection between the harness wire & sensor get cruddy (rusty / corroded / etc) system may not trigger fan to run or will shut it down too soon....

99% of the failures is due to wire to sensor: skimpy wire melts / corrodes....

and 74.8% of all statistics quoted are made up

Pete

 

[crackdpot]

Sounds about 98.7% more honest than most pretentious purveyors of professional practice.

Thanks dude!

I'll take a look.

Dang I like this forum already!

 

[BackFromTheDead]

I had the same problem, as the ground wire between the exhaust manifold and the carb cooling fan broke right on one side of the green sensor between the two.

I haven't gotten around to replacing/repairing/rewiring the sensor, so I just grounded it under the hood on an fender panel bolt. It works fine now...always runs for about half an hour after I turn the engine off. It hasn't seemed to have any effect on my battery charge, and with the fan preventing fuel burnoff or carb overheating, my truck starts great every time.

If anyone thinks this is a bad idea, let me know...I probably just need a little kick in the butt to fix the original wire and reconnect it to the green relay coming off the exhaust manifold.

 

[crackdpot]

I was on the way up a mountain in Nat'l Forest when I first experienced the difference (without the fan). Started vapor-locking on startup. Winter-time should be a little less challenging, I'd imagine. Still, guess there was a good reason for Toy makers putting it in there.

Thanks for all the advice!

 

[crackdpot]

Success!

As mentioned, I found the wire (spliced by previous owner and fried off).
I grounded it to body bolt and it runs on shut-off.

Q: I'm assuming that the length of time that the fan runs is set by a timer and would be the same whether it's running through the sensor or direct grounded., Right?.

I don't mind it running every time I shut down. I just don't want to put unnecessary strain on the battery. (until I install 2nd one.)

Thanks again for all the help.

 

[sterling]

It Lives!!

Thanks to all who posted my carb fan is back up and running on the 60. By far the easiest fix yet, would still like to know if grounding this wire on the fender has any ill effects though. Guru's please chime in!

Thanks again

Ryan

 

[crackdpot]

Motion 2nd (ed).

Thanks

Echo Questions.................

 

[mrsvle]

First Pic: Carb Cooling Fan Sensor

Second Pic: Where it lives (red circle).

 

[rhett121]

Grounding it to the firewall has no ill effect. I've run mine like that since the sensor threads broke about 8 years ago. It runs for about 1/2 hour when I turn off the key.

 

[sk8salomon]

my wire broke off as well a while back. replaced the wire with new crimp end and fan worked fine. 2 months later my carb fan stopped working again? took a look and found the wire broke off again right by the connector. i then ran electrical tape around the connector plastic body then installed some plastic wire loom on the wire. no problems as of yet 3 months later. i guess the heat is causing the wire & plastic insulator to get brittle & crack.

 

[HntWhtTail]

Success!

As mentioned, I found the wire (spliced by previous owner and fried off).
I grounded it to body bolt and it runs on shut-off.

Q: I'm assuming that the length of time that the fan runs is set by a timer and would be the same whether it's running through the sensor or direct grounded., Right?.

I don't mind it running every time I shut down. I just don't want to put unnecessary strain on the battery. (until I install 2nd one.)

Thanks again for all the help.

The fan only runs while the sensor is hot enough to keep it grounded, so since connecting mine to the sensor, it will run for varying lengths of time depending on engine temp. When grounded to the frame the length of time is controlled by a relay or switch set to run for a specific time this switch would also turn the fan off when connected to the sensor should it run that long. The only possible bad thing about running grounded to the frame, is that the fan running could run down the battery. Mine was hard to start on very cold mornings running it this way, probably had more to do with the cheap Walmart battery than the drain caused by the fan.

 

[soggy60]

Welcome to the Carb Cooling Fan Club

There is no ill effect by grounding the wire instead of fixing (connect to sensor).

As others have mentioned, there is a run time limiter built into the circuit (in the black box I mentioned above).

Another 'feature' of a properly wire system, fan runs for a while depending on temp (as others have mentioned) , but if it's a really hot day & you just shut down from a haul on the turnpike, it will come on again as the sensor re-heats from the block . . .

The purpose of the system is, as some have noted, to reduce carb boil- off: emission control and hot-start driveablility.

 

[crackdpot]

You guys ROCK!

To put it in the vernacular of my 17 yr old.

Thanks heaps, tons & loads.

G'Day!

 

[crackdpot]

Gonna try & find some high temp type wire & connect the right way.
Like to think it'll start up again if "re-heated" by hot block and not run any longer than it has to when I'm 50 miles from town.

Don't know how helpful this thread has been to everyone else, but in my previous searches for the answer, came across alot of the same questions.
Maybe we should "highlite" it somehow so's other questioneers can find it easier. Don't know zactly how to do that.....suggestions?