I don't see the ground switch wire to your sensor. Sensor isn't required, it is only to provide temperature resistance to ground switch wire to unit.
Locate the ground wire (Blue/Black or Solid Blue) off harness on driver fender (single wire, would be in combination with fuel cut solenoid...
I have had my coolingfan working great in the past. Once it quit and I replaced the 5A inline fuse under the dash, worked again just fine. Recently it stopped working again only to find everything connected and inline fuse looking just fine but replaced with a new one anyway but to no avail...
Found my carbcoolingfan/controller post. It has photos and an explanation of some of the differences in the early and late models.
Repair of '79 - '80 carb cooler fan controller circuitboard
Your 1978 model should have the M3 type relay (a small silver cylinder in the wiring harness) that...
There’s a lotta related info available on MUD, Tom.
Below are the results of a quick search for “carbcoolingfancircuitboard” in this forum... you could try other parameters and get more results.
@bsevans repaired his board and IIRC @unixman repaired or rebuilt his.
I got bored with...
I don’t recall what the carbcoolingfan “activator” (I cant recall the name) looks like, but I think this “button” is it.
it would normally be mounted under the manifolds and would close a circuit, by activating a ground, to trigger or activate the carbcoolingfan at a certain temp.
Old...
My '79 40 didn't have the blower for the carb when I got it about 6 years ago. Until recently I was ignoring my hard-starts after the engine was warm and then sat for a while. I started reading the LONG threads about guys on MUD getting their carb coolers working and having much success with...
Guys,
This forum is awesome thank you in advance for the help...finally got the 40 running (after new carb, rear main seal, oil pan gasket, valve adjustment, clutch/throw out bearing work, rear output seal, fan clutch, new cooling hoses, thermostat, water heater, radiator, cooling system flush...
Several years ago I found out my '78 had something commonly referred to as a "carb fan" and associated thermistor and controller. I didn't notice it was there because it had never worked. A PO had replaced the fan controller's inline 5A fuse with a 15A fuse. That's likely why the controller...
The fuse for the coolingfan is a 15 amp fuse and appears ok, and the manifold temp sensor is connected, have not pulled the box apart yet, will do tonight. Thank you for your quick service on providing me the fusible link, very nice work!
I purchased my current FJ40 non-running, carburetor in a box, sitting for 15 years. PO had a dual battery setup, which had been removed when I bought it, lots of auxillary lights which I removed, and had used 30 amp fuses throughout. I have since replaced all fuses to the correct amps, replaced...
Thanks Gator. Thats one of my many nephews. While I do not have any young 'uns of my own there is usually one or two nephews around here on the weekends to lend a hand. Joe is the youngest but he is also mischievous . . . he likes to hide important components when you need them the most...
Yep, the light blue wire with the green plug, below the brake pressure switches, shown in your 2nd and 3rd photos runs over to the coolingfan temp switch. It mounts through an L-bracket bolted to the manifold.
The original wire to the switch can fail due to heat (notice the heat sleeve on...
Does Any One Know Where To Obtain The Following Information About The CircuitBoard For The Carburetor CoolingFan Box???!!!!
Does It Exist?
A schematic drawing of the circuitboard, and a PEB assembly drawing with reference designators
If I can find this info my carbcoolingfan will be...
I'm in the middle of trying to fix my carbfan as well. I'm not going to be much help in the aftermarket thermo switch discussion because I've always just grounded that lead rather than try and replace it. The carbfan runs for about 20 minutes after engine shut off and then stops.
My buddy...
Well when I pulled my board out it was obvious what I needed to replace. If you hold the board with the components facing you, orient the board so the connector is to the top, relay to the bottom. There are two diodes lower right corner on mine that were fried, and had crappy soldering joints. I...
Gentleman we have an update. My buddy that's helping me with the problem as I've mentioned is a electrical test engineer for a very large electronics company. And in my humble opinion put together a series of steps that is pretty full proof in allowing one to figure out where the problem is...
My carbcoolingfan did not function when I bought the vehicle in 1987. I went through the system and resolved the issue to the control circuit. I pulled the box under the dash on the drivers side and exposed the circuitboard and found that the problem appeared to be some of the solder joints...