Carb fan wiring/heat sensor

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gnavarroo

gnavarroo

10 Year 15 Year
Joined
Mar 15, 2006
Threads
39
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181
Location
Las Cruces, NM
So i'm messing with the carb fan trying to get it to work... did a little back tracking and i think I found the manifold heat sensor.... can any one identify? the sensor had a wire clip with a small hint of a wire tuft poking out indicating that a wire was once there. i looked around the area for a lone wire and found a crispy brittle blackened green wire that seemed too short to reach the sensor.
1. Just to make sure is this the sensor that controls the on/off of the carb fan.
2. Does anyone elses wire harness look like this? ( the green plug goes to the carb fan) That green wire that i'm pointing to: is it the one that goes to the sensor?
 
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i'm anxiously waiting those answers. Seems like the same deal with mine on the 87.
tjg
 
Yes and probably yes. Thats the thermo sensor and the green (more blue?) wire looks just like mine did. I ran it to the sensor, and she works perfectly now. I verified mine by running the broken wire to a good ground and seeing if the fan started. I think you need to do it right after shutting off the ignition since there is also a timer (30 min?) somewhere else. The thermo sensor grounds the fan allowing it to run until the engine is restarted, the temp drops, or the timer relay shuts it off.
 
that is awesome. one more project for the weekend.
 
I'm willing to bet that it is, I still haven't found mine, but I did find out that the PO did some funny stuff with the carb fan circuitry... Try grounding it to the body and see if the fan starts up. You might have to turn the engine on-then-off to trip the controller before it engages, I don't know, I never figured the thing out...

Have fun!
 
gulp3000 said:
Yes and probably yes. Thats the thermo sensor and the green (more blue?) wire looks just like mine did. I ran it to the sensor, and she works perfectly now. I verified mine by running the broken wire to a good ground and seeing if the fan started. I think you need to do it right after shutting off the ignition since there is also a timer (30 min?) somewhere else. The thermo sensor grounds the fan allowing it to run until the engine is restarted, the temp drops, or the timer relay shuts it off.
Click to expand...

cool, thanks I will try doing that. I'm hoping that the problem will be solved... but before i put the fan back I'd like to pull the exhaust manifold off and put a new gasket in there. Any tips on that, anyone?
 
step-wise solution to carb cooling fan

gnavarroo said:
So i'm messing with the carb fan trying to get it to work... did a little back tracking and i think I found the manifold heat sensor.... can any one identify? the sensor had a wire clip with a small hint of a wire tuft poking out indicating that a wire was once there. i looked around the area for a lone wire and found a crispy brittle blackened green wire that seemed too short to reach the sensor.
1. Just to make sure is this the sensor that controls the on/off of the carb fan.
2. Does anyone elses wire harness look like this? ( the green plug goes to the carb fan) That green wire that i'm pointing to: is it the one that goes to the sensor?
Click to expand...

This guy knew what I was trying to ask... found one of his replys on another thread on the same subject useful. Thanks again pete!

soggy60 wrote:
1. Carb Fan Wire: 'srtip' a little insulation off the small wire (in the picture you posted) and junp it to ground. The fan should come on . . .
My fix: crimped a length of "oven" wire to blue wire, crimp an eyelet on other end. tucked a loop into fan exhaust....
WHEN you connect eyelet to sensor, use 2 wrenches; one very skinny for nut at base of 'stud' on sensor...otherwise, tightening just outside nut may twist guts of sensor.

2. mainfold gasket. Time consuming but not really hard. Remove carb, remove emission 'manifold', remove bolts & nuts holding manifold to head. ( loosen ring on exhaust pipe by tranny, loosen U-clamp in front of cat converter). Pull manifold away from head- it won't go fat, maybe inch and a half or so...just enough to scrape old, slide in new.


Have fun, kiss some knuckle skin good bye

pete


__________________
Nov 85 FJ60
 
Oh, and thanks to everyone else that posted with tips on this thread... Hope it works. will try to fix this week end
 
Eurika! It worked!

JBBenson said:
Please post the results if and when you get it working.

I am having a lot of trouble getting mine to work, would like to know your experience.
Click to expand...

Hot Dawg! a cheap fix... couldn't find any oven wire in town to save my life, though. I would strongly recomend it. I see myself replacing the skimpy wire that I installed after a short while, but now that I know what the problem is it won't be so bad. I just have between now and then to hunt down a 2' section of oven wire. I'm guessing it's some sort of high temp wire with a fiberglass coating on it, yes? Called around town to all the appliance repair shops asking for it and NO ONE had it...Bumber.
If anyone else has this problem I strongly recomend this thread. Start here. The only other thing it could have been is the relay... www.cruiserparts.com has them for $30 I believe. Relay seems to be good to go. I'm going to fire it back up and let it run again for a while to make sure it wasn't some sort of mechanical fluke or that it's not just going to work once!
Now..... I think I'm going to have a cold one:beer:
 
Hey,

I have just discovered what was wrong with mine. Like a big DA, when I tested the fan by grounding the sensor wire , I forgot that the car had to be in "shut-down" mode, i.e. the timer had to be running. Forgot that little detail.

So THATS why it never worked. Total idiot....

Well, today remembered to test right after shut down and lo and behold the fan works, so it IS the manifold sensor after all. Whoda thunk it?

Anyway, if you need a black box relay, I might sell you mine, got it from cruiserparts, but didn't need it after all.
 
In the first 2 pictures, yes that short black wire is the one that goes to the sensor and that is the sensor in the second picture. My fan didn't work this morning, but after reading this thread and messing around for a while, my fan now works. My wire was so brittle that it broke at the sensor and kept breaking every time I tried to strip it. I fixed it by finding a small piece of newer wire the same size and connecting that to the sensor then cutting the old wire back a few inches to where it wasn't as brittle and splicing them together. Took me forever to find the sensor, but once I did it didn't take long to fix it. I also took the fan apart and cleaned some crap out of it, took maybe 15-20 minutes. If anyone needs pictures, just send me a pm.
 
MANIFOLD GASKET. My air rail completly deteriated as I was trying so carefully to remove it. Huge thanks to "SUPERDUPERCRUIZER" for selling me his emmisions compoients.
HI TEMP wire has a cloth type jacket. Most all hardware stores carry it. If you are unable to locate I would be happy to drop a lenth in the mail to you. PM me if needed.

Jim
 
Here's a "complete" photo from my FJ62
FJ62-Carb-Cooling-Temp-Swit.webp
 
easy to see on 62

Ming89FJ62 said:
Here's a "complete" photo from my FJ62
Click to expand...
Is that wire with the fuse link the one that goes to the sensor? Wow, easy to see and it looks easy to get to... On 60, if the wire is burned up to the sensor you may never know it was there unless you peeked at the Ex manifold from under the eng. compartment... will post pics this afternoon
G.
 
There's no fusable link connecting the manifold temp sensor - just the Toyota wire connector. The reason the sensor is so easy to see is that I'm running MAF 3FE headers so all the heat shielding that would normally be bolted to the OEM exhaust manifolds have been removed.

Harry
 
Ming89FJ62 said:
There's no fusable link connecting the manifold temp sensor - just the Toyota wire connector. The reason the sensor is so easy to see is that I'm running MAF 3FE headers so all the heat shielding that would normally be bolted to the OEM exhaust manifolds have been removed.

Harry
Click to expand...

So then, here's mine (you showed me yours now I show you MINE!)
No headers, stock manifold, hard to see with out getting under truck... here it is for those who don't have headers... crawl under LC and you'll see. From the top, do you see (or don't see) how the blue wire just disapears into bliss......Worked like a charm again this morning! Just wondering how long that wimpy wire's gonna last.

George
 
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