fj 60 carb fan not working

[sdbrassfield]

A full cycle is around 20-30 minutes and is timed when the wire is grounded. It can and will turn on and off and will run multiple times or cycles when run off temp sensor. The temp sensor usually does not fail it is the wire that gets burnt in two. An easy fix is to ground the wire and it will run after each shutdown. It can be a pain to splice and put back on sometimes. Grounding is just an easy temporary fix, or permanent if you want to leave it that way.

Rationalization: These rigs are overengineered you know? In addition, a known problem with all one piece intake and exhaust maniflods (jeep I-6's, chevy, ford etc..) are vapor lock and effects of heat on the manifold and carb areas. Consequently, toy engineered the i/e manifolds to be cooled at shutdown for easier restarts and hopefully less stress and damage to the area(s). Sound like a good idea to me especially if I were out on the savanna or desert...

 

[tag3]

Mine has been grounded to a screw on the fan housing itself. Runs about 20 min. and shuts off automatically.

 

[Spike Strip]

Then please rationalize for me a justifiable reason why Toyota would bother to install a temperature sensor? That manifold is anyway hot within a couple of minutes every time you run the engine.
From automotive mass production calculus a total waste of unwarranted added mfg. cost.

FWIW My sensor is 25 years old original 309,000 miles and works.
BTW I hooked mine up direct to ground on a cold engine and the fan started running....and running....and running...

Perhaps as you posit, in your post, it's a safety issue if the thermo-switch sticks grounded, or the wire grounds.... I dunno, and frankly I don't care, I just know it is, and that's why I like Land Cruisers: Over-engineered.

I don't wanna get personal, here, but I'm betting your parents didn't beat you enough

I kid.

 

[Boosted91]

check

Ok I read this post earlier today and I grounded the wire out and the fan came on but did not shut off. I let it run for an hour. I hed to take out the dome fuse and it stop. Put the fuse in and it stayed off till I turn key on. Turned key off and the fan stayed on again.

Now what do I need to do to fix My carb fan?

My truck is a 87 fj60....

 

[Spike Strip]

The timer/relay may be bad or someone may have by-passed it. Dunno. But what others have done is just wire a toggle switch in line with the wire that you ground and manually turn the fan off. They put the toggle in the cab. Really don't need a toggle, though. A momentary switch would be better, I think.

 

[chitown40]

The timer/relay may be bad or someone may have by-passed it. Dunno. But what others have done is just wire a toggle switch in line with the wire that you ground and manually turn the fan off. They put the toggle in the cab. Really don't need a toggle, though. A momentary switch would be better, I think.

After trying a few junkyard sensors I gave up on the temp sensor running the fan. I connected an old Cressida overdrive toggle switch in line with the ground wire and can control the fan operation manually. In the winter I leave it off. In the summer or very hot days I'll turn the switch on. The fan grounds, and then the TIMER/RELAY takes over and lets the fan run for 20 mins or so and then shuts off.

 

[Boosted91]

I have an extra relay. I'll change it and see what it dose. If it dose the same thing I will just put the toggle switch in. easy enough.

 

[CenTXFJ60]

Reviving an old thread to see if I can get some additional direction. The 60 I’m working on is an 85. My carb fan works direct with the battery. No power to the dome light or the 5 door switches. All new dome lights installed. And the 7.5 amp fuse is good in the fuse box (and has 12 volts) I direct wired the ground for the carb fan. Ohmed it to the fan plug and she’s good. I’ve read a bunch on this and folks mention an inline 5 amp fuse. No idea where that would be and I’ve stretched out a few spare harnesses on my shop floor and nothing like this is visible. I even swapped out the carb fan computer board in the passenger side kick panel. No dice. These two items are the last of the punch list on a frame-on restoration I’ve been doing the last few years. Threads in my sig. pic for reference.

 

[CruiserTrash]

Reviving an old thread to see if I can get some additional direction. The 60 I’m working on is an 85. My carb fan works direct with the battery. No power to the dome light or the 5 door switches. All new dome lights installed. And the 7.5 amp fuse is good in the fuse box (and has 12 volts) I direct wired the ground for the carb fan. Ohmed it to the fan plug and she’s good. I’ve read a bunch on this and folks mention an inline 5 amp fuse. No idea where that would be and I’ve stretched out a few spare harnesses on my shop floor and nothing like this is visible. I even swapped out the carb fan computer board in the passenger side kick panel. No dice. These two items are the last of the punch list on a frame-on restoration I’ve been doing the last few years. Threads in my sig. pic for reference.

View attachment 3761152

View attachment 3761153

Never heard of that inline fuse! Do you have 12VDC between the hot wire at the fan connector and any ground? Continuity between the back of the thermistor and the fan connector? I don’t recall a computer in the mix here - the thermistor is the path to ground through its threads on the exhaust manifold. When cold resistance is high, when hot the resistance is low and allows the ground path. I guess there must be some switching to make sure the fan is only on when the engine is off though.

 

[yotadude520]

Never heard of that inline fuse! Do you have 12VDC between the hot wire at the fan connector and any ground? Continuity between the back of the thermistor and the fan connector? I don’t recall a computer in the mix here - the thermistor is the path to ground through its threads on the exhaust manifold. When cold resistance is high, when hot the resistance is low and allows the ground path. I guess there must be some switching to make sure the fan is only on when the engine is off though.

When I removed mine in the process of my LS swap I did find the carb fan controller - it's behind the passenger kickpanel and looks like this

@CenTXFJ60 My carb fan worked prior to pulling so if you want to take a shot with my controller PM me.

 

[CenTXFJ60]

When I removed mine in the process of my LS swap I did find the carb fan controller - it's behind the passenger kickpanel and looks like this

View attachment 3761342

@CenTXFJ60 My carb fan worked prior to pulling so if you want to take a shot with my controller PM me.

Thank you very much for your offer. I do have a few of them around here and did swap in one to test and no change. I wish I had the electronic smarts to know how to test and see if one of those controllers were actually the issue

 

[CenTXFJ60]

Never heard of that inline fuse! Do you have 12VDC between the hot wire at the fan connector and any ground? Continuity between the back of the thermistor and the fan connector? I don’t recall a computer in the mix here - the thermistor is the path to ground through its threads on the exhaust manifold. When cold resistance is high, when hot the resistance is low and allows the ground path. I guess there must be some switching to make sure the fan is only on when the engine is off though.

So I do have that thermistor on the bottom of the EGR tube. But I chose to direct ground that blue wire vs using the thermistor to see if that was my problem. And no, I’m not getting 12v to the plug at the fan. What I’ve read (and talking with @LETSROLLEM ) is that 12v supply shares some of the same track as dome lights which is the only other thing not getting correct voltage. After googling this and reading the same 4-5 mud threads several times it’s mentioned these two service areas share a 5amp inline fuse. I believe it’s on earlier models but no idea of the cutoff year. May even be 40 related and not on 60’s. More research ahead.

 

[CruiserTrash]

So I do have that thermistor on the bottom of the EGR tube. But I chose to direct ground that blue wire vs using the thermistor to see if that was my problem. And no, I’m not getting 12v to the plug at the fan. What I’ve read (and talking with @LETSROLLEM ) is that 12v supply shares some of the same track as dome lights which is the only other thing not getting correct voltage. After googling this and reading the same 4-5 mud threads several times it’s mentioned these two service areas share a 5amp inline fuse. I believe it’s on earlier models but no idea of the cutoff year. May even be 40 related and not on 60’s. More research ahead.

The dome circuit really seemed like Toyota’s trash bin on these trucks. “Uh, guys. We’re all out of fuse spots and we have all these things left that need fuse protection, what do we do?” “I dunno, throw them all on the same circuit and use a weirdly small fuse that’s impossible to remove with adult sized hands. And make it 5A!”

I know there’s a splice hidden inside the harness behind the alternator, so a hidden fuse wouldn’t surprise me. Also, what about one of the dome light door switches shorting out? Might be shorting some amount of voltage to ground which would cause issues: the system voltage would be lower and the body ground would have a slight voltage on it too.

 

[CenTXFJ60]

The dome circuit really seemed like Toyota’s trash bin on these trucks. “Uh, guys. We’re all out of fuse spots and we have all these things left that need fuse protection, what do we do?” “I dunno, throw them all on the same circuit and use a weirdly small fuse that’s impossible to remove with adult sized hands. And make it 5A!”

I know there’s a splice hidden inside the harness behind the alternator, so a hidden fuse wouldn’t surprise me. Also, what about one of the dome light door switches shorting out? Might be shorting some amount of voltage to ground which would cause issues: the system voltage would be lower and the body ground would have a slight voltage on it too.

Ok Jim…so your thought in the last paragraph is rolling right over my head . voltage to ground??? I have zero voltage at the drivers front door switch as well as zero at the center dome light. I perused the wire diagram in my FSM and found nothing on the carb fan. Did find the dome light and 5 switches.

It looks to be powered by row “B”. Problem for me is I have no idea how to read this and do not know where “B” goes. From removing/installing several 60 harnesses I know where to tap in with the multimeter in the kick panel. Also found the power for the headlight reservoir is tied into “B”. Will dig around checking for voltage a bit more manana.

 

[CruiserTrash]

Voltage to ground meaning a short! Maybe there’s some crud in on of the door switches that’s conducting a little voltage to the body (I.e., acting as a resistor). But if you don’t have 12V at the door sensor or the dome something else is likely going on. Is the fuse holder for that circuit getting power? Sometimes a fuse can look good and be bad too.

Anyway back to the fan. I think the earlier wiring diagrams are much easier to read than the multi page madness that n the later FSMs. I can email you an early one if you don’t have it. I’ll take a peak tomorrow too.

 

[CenTXFJ60]

Voltage to ground meaning a short! Maybe there’s some crud in on of the door switches that’s conducting a little voltage to the body (I.e., acting as a resistor). But if you don’t have 12V at the door sensor or the dome something else is likely going on. Is the fuse holder for that circuit getting power? Sometimes a fuse can look good and be bad too.

Anyway back to the fan. I think the earlier wiring diagrams are much easier to read than the multi page madness that n the later FSMs. I can email you an early one if you don’t have it. I’ll take a peak tomorrow too.

That would be awesome. Olddogcruisers@gmail.com. My FSM is from 1984

 

[CruiserTrash]

Sent you the FSM. Here's a couple screenshots. Looks like it's on both the Dome fuse (what the power bus line at the top right of the first photo goes to) AND the 10A "Engine" fuse". There's also two relays.

 

[caladin]

Here is what I used to fix mine, and will add next
I had lots left over, but except for the sensor it's all cheap

Heat shield
SUPERFASTRACING 5 Feet Heat Sleeve Fiberglass Adjustable Heat Shield Sleeve Black 5FT X 6MM(1/4") for Car Wire Loom https://a.co/d/fjhf2mo

Wire that can handle high temp (has one layer of heat shield, but I put above on too.
PATIKIL 9.8Ft 15AWG Electronic Wire, -30 to 200 Degrees Celsius Insulated High Temperature Resistant Electrical Flexible Silicone Cable for Lamp Boiler Heater, Blue https://a.co/d/6XoHPI2


Stainless Hi temp ring terminal(hole was big, had to add a washer, try 1/8"

Limited-time deal: Morris Products High Temperature Ring Terminals – 16-14 Wire Size - ¼-inch Stud Size – Nickel-Plated Steel – For HVAC, Industrial Kilns, Electric Space Heaters, Commercial Ovens, Fryers – Pack of 100, (12520) https://a.co/d/28S5ayR


Sensor another thread on mud says, will work(have not tried yet)
Spal 185-TS Temperature Switch https://a.co/d/5uCtkll

 

[CenTXFJ60]

Here is what I used to fix mine, and will add next
I had lots left over, but except for the sensor it's all cheap

Heat shield
SUPERFASTRACING 5 Feet Heat Sleeve Fiberglass Adjustable Heat Shield Sleeve Black 5FT X 6MM(1/4") for Car Wire Loom https://a.co/d/fjhf2mo

Wire that can handle high temp (has one layer of heat shield, but I put above on too.
PATIKIL 9.8Ft 15AWG Electronic Wire, -30 to 200 Degrees Celsius Insulated High Temperature Resistant Electrical Flexible Silicone Cable for Lamp Boiler Heater, Blue https://a.co/d/6XoHPI2


Stainless Hi temp ring terminal(hole was big, had to add a washer, try 1/8"

Limited-time deal: Morris Products High Temperature Ring Terminals – 16-14 Wire Size - ¼-inch Stud Size – Nickel-Plated Steel – For HVAC, Industrial Kilns, Electric Space Heaters, Commercial Ovens, Fryers – Pack of 100, (12520) https://a.co/d/28S5ayR


Sensor another thread on mud says, will work(have not tried yet)
Spal 185-TS Temperature Switch https://a.co/d/5uCtkll

I appreciate the information as this will be useful. With your fan did you have an issue getting 12v to it or just had to make the ground side bulletproof ?

 

[CenTXFJ60]

Ok. So I am the first to come clean when I completely get wrapped around the axle and forget to dissect the most obvious issue. What my issue ended up being was the female receptacle on the dome fuse was stretched out. Like when someone jambs a wire in for fog lights or something added on. I’ve done this with my main cruiser in the past. So I developed a punch list of little things to check which this was one of the items. I was so focused on things that I never checked the dome lights and about 30 min later I was making a video for @CruiserTrash as he was helping me offline. During the video I clicked on the dome light and boom…everything worked including the carb fan. I originally posted the video but my language was a bit foul due to my excitement so I removed it.
I learned a lot about these two systems through this process, but the main thing here is to try and remember to start with the most obvious and usually simple steps first.
Thank you to everyone for your quality input.