why not?
fj40 carb cooling fan...do you run yours? (1 Viewer)
- Thread starter michaelharrisco
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No it doesn't. The white "Woods" 30 minute timer above (along with other similar brands) is a mechanical spring wound device. It requires no power to run it. Twist the knob and the connection is made across the wires. This spring loaded timer slowly "ticks down" until it reaches the end, you can hear it ticking....then it cuts off the circuit. As simple as can be. I have been using one for my messed up carb fan & wiring for over 15 years. Only thing is... you gotta remember to twist the knob when you turn off the car.. though it becomes habit. These "wall timers" are typically used for turning off AC lights and such, but can be used to turn off any thing electric. Doesn't have to be AC, and no power is required for it to do it's deed.
My carb cooling fan--Used bilge blower from a Searay boat. Wired to the orig harness at the DS front. Used a timer scavenged from a toaster oven to power it, as the fan relay did not work.(I'm going to repair it based on the info in this thread-cold solder joints, etc.). One thing to note is you don't want the fan blowing cooler air directly on the carb/intake/exhaust-risking cracks here. Mounted mine so it blew down towards the exhaust connection-much thinner metal there so it can handle the temp change without issue. Really helped the hot starting problem I was havingView attachment 913137
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What "thermo switch" are you using? It doesn't look familiar, but then your setup doesn't need one anyway does it?
No, it doesn't need the switch. I tried making it work with a switch I got from Orangefj45, but the relay module was bad(I'm pretty sure) I just hardwired a timer(one out of an old toaster oven) to the blower. It's not automatic, but that's ok for now. I just crank the timer to 15-20 mins when I shut the engine off--works just like an egg timer, and keeps the carb cool--
Looks like it is very similar to Output Shaft's setup.
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I connected my fan on my '78 this past weekend using an adjustable temperature sensor and sending ground to the cooling fan relay module. I adjusted it to approx. 185 deg. and will probably tweak some more. What I noticed, though, is that the fan is turning on while driving after awhile. It stays on with the ignition off and eventually turns off.
Reading through the other pages (and the FSM pages posted) it was noted that the fan should not come on while the ignition switch is on. Any ideas what could be wrong?
Reading through the other pages (and the FSM pages posted) it was noted that the fan should not come on while the ignition switch is on. Any ideas what could be wrong?
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Any pics? And is it a 2F only thing?
Your fan is getting 12V regardless of the ignition state which means you have probably circumvented the fan controller relay itself or the relay has failed in the closed (allowing 12V to the fan) position. If that's the case, your fan will run whenever the temp is over 185F (85C). A schematic, picture, or more detailed description of how you connected the temp sensor would help.
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After not being able to repair my "Cooling Fan Control Timer" relay module, I finally bought another one and grounding the thermistor lead confirmed the fan came on after turning the key to ACC and then OFF. I drove her to work this morning, a seven-mile (11 minute) drive with an outside temperature of 74F. The fan came on when I arrived and switched off the ignition. It stayed on about 10 minutes. Wish I'd had this working for the previous 16 years. Very cool.
Incidentally, when I drove home today with an outside air temp of 99F and then parked in the garage, the fan didn't come on immediately, but about 45 seconds later. Obviously, the air temp rose in the compartment after parking which implies the controller is reading the resistance/voltage value from the thermistor well after the key is switched off.
Incidentally, when I drove home today with an outside air temp of 99F and then parked in the garage, the fan didn't come on immediately, but about 45 seconds later. Obviously, the air temp rose in the compartment after parking which implies the controller is reading the resistance/voltage value from the thermistor well after the key is switched off.
The sensor I am using is such as this one - http://www.amazon.com/dp/B000C39C6I/?tag=ihco-20 that I had laying around. I connected one terminal to ground and the other end to the original sensor wire. Simple, as when it reaches the desired temperature the relay closes and completes the ground circuit.
Let me remove the timer module when I get home and I'll take a look inside. Should have done that before re-installing to see if I needed to re-solder anything. Will update tomorrow if I find anything.
Let me remove the timer module when I get home and I'll take a look inside. Should have done that before re-installing to see if I needed to re-solder anything. Will update tomorrow if I find anything.
if a truck has a manual choke…
and a carburetor...
and maybe a manual throttle control knob...
and manual locking hubs….
and has to slow to almost a stop to shift into 4WD low…
and has timing gears
and push rods
and has an engine that was basically designed over 60 years ago….
Does something that contains a "thermistor" even belong in it?
Just sayin…
(but I might try to install one too….I'm getting tired of turning that knob).
and a carburetor...
and maybe a manual throttle control knob...
and manual locking hubs….
and has to slow to almost a stop to shift into 4WD low…
and has timing gears
and push rods
and has an engine that was basically designed over 60 years ago….
Does something that contains a "thermistor" even belong in it?
Just sayin…
(but I might try to install one too….I'm getting tired of turning that knob).
Very true! And actually my rig is/was running with no problems until recently with this hot weather for over 25 yrs. For that period I was running my stock carb with an electric fuel pump + headers AND the carb fan removed. Never a problem with that setup and actually quite impressed the pump is still working. A few months back I installed a '73 carb (crazy about those mechanical secondaries) and a mechanical fuel pump (nostalgia). Once the heat hit here in El Paso, I noticed more difficulty starting and minor fuel issues with this setup, even with the return line. This carb seems more sensitive to heat. So here is hoping the carb fan will fix the issue.Anyways, happy news
--- my problem with the fan turning on with the ignition on was that the black/yellow wire going to the timer module was disconnected and taped off. Must have done that when I was a teenager for one reason or another. I connected the wire, drove around, got off the Cruiser, no fan running, turned off the ignition, fan on. 
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The BY wire is what the controller uses to tell when the ignition is switched off. If your controller works, why did you use an aftermarket temp sensor rather than the OEM thermistor? To modify the threshold temperature? Just curious.
Correct on the BY wire. The controller always thought the ignition was "off".
As for the OEM thermistor, I took it off a long time ago (along w/the controller & fan) and I have it somewhere among my parts stash, just got to find it. The current sensor was right at hand as I used to use it for my '81 Volvo and, to tell you the truth, I kind of like it for its adjustability. As a matter of fact, I adjusted it to a slightly higher temp. this afternoon. I currently have it tied under the carburetor insulator/spacer and the intake manifold. Subject to change of course.
As for the OEM thermistor, I took it off a long time ago (along w/the controller & fan) and I have it somewhere among my parts stash, just got to find it. The current sensor was right at hand as I used to use it for my '81 Volvo and, to tell you the truth, I kind of like it for its adjustability. As a matter of fact, I adjusted it to a slightly higher temp. this afternoon. I currently have it tied under the carburetor insulator/spacer and the intake manifold. Subject to change of course.
If someone has the early sensor that mounts above the head, could you measure the resistance across the terminals when it is cold and when it is hot please? I have a 'parts wanted' thread for this part too.
This one:
I know a lot more about the earlier system on my '76 that I ever wanted to know. I have a full schematic of the controller. The operation of the earlier type is different than the later one in my '78 and the earlier circuit is much simpler.
In the later one, the sensor provides ground when it's hot. In the earlier one, the sensor provides power to part of the circuit through the sensor. I think it's a thermistor that does not go to zero ohms when it's fully 'on'. The later one may be a thermal switch, providing ground or not and nothing in between.
The upshot, I think, is that you can't just bypass the sensor in the earlier circuit, or the fan will be 'always on', regardless of the 'timer' or the ignition power. This is what I've got right now. I'm thinking if I bypass with a resistor value that matched the sensor it would work as it should.
The earlier one that I have uses a big capacitor as the 'timer'. The cap is charged by the ignition power and then drives the relay through a transistor as it discharges, which presumably takes about 20 minutes.
This one:
I know a lot more about the earlier system on my '76 that I ever wanted to know. I have a full schematic of the controller. The operation of the earlier type is different than the later one in my '78 and the earlier circuit is much simpler.
In the later one, the sensor provides ground when it's hot. In the earlier one, the sensor provides power to part of the circuit through the sensor. I think it's a thermistor that does not go to zero ohms when it's fully 'on'. The later one may be a thermal switch, providing ground or not and nothing in between.
The upshot, I think, is that you can't just bypass the sensor in the earlier circuit, or the fan will be 'always on', regardless of the 'timer' or the ignition power. This is what I've got right now. I'm thinking if I bypass with a resistor value that matched the sensor it would work as it should.
The earlier one that I have uses a big capacitor as the 'timer'. The cap is charged by the ignition power and then drives the relay through a transistor as it discharges, which presumably takes about 20 minutes.
FYI: The manifold temp sensors are not easy to find at SOR. They are available here:
http://www.sor.com/catproducts.sor?from=182&part.number=182-85&tabpage=TAB1
From Beno, the part number for the (discontinued) 1/76-9/77 sensor is 89428-60030.
http://www.sor.com/catproducts.sor?from=182&part.number=182-85&tabpage=TAB1
From Beno, the part number for the (discontinued) 1/76-9/77 sensor is 89428-60030.
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All good, once I extract a snapped off bolt on my intake manifold where the sensor mounts I should be getting her going....
