Another One Bites The Dust - Fan Controller

[ASSFROW]

looks like that pot leaked out? the 50v one. I would not rub your eyes after touching it.

He mentioned he had to pee, hopefully he washed his hands.

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[croppz]

Is this the 300+ dollar fan controller?

If so I wouldn’t be very pleased

 

[Heimkehr]

these fan controllers...are not environmentally protected, like all critical systems in your vehicle should be. If these fan control modules fail, the fan quits working and overheating is rapid.

If these are used with an interface harness like THAW developed, and protected, you should have a reliable system.

@THAW
Interface harnes? Do tell, please.

I ask because, being interested in the PCM fan controller but also being cognizant of the required wiring work, I reached out to Jon Schaefer at RPM Extreme last year to inquire about a plug-and-play harness. This is the response I received:

"There is no other location to access the wires needed that we could use a T-style plug in connector.

The ECU is the only place where all the wires are in one location and easily accessible. Splicing in at the ECU is the best way."

 

[ScotM]

Brother calls me yesterday, says the fan is not running on his jeep. Apparently, I am forever tied to this jeep.

I figure it's one of three things, Z-case fuse, Green CAN bus junction block, or the aftermarket fan controller. I load up a carbon pile tester as well as an electronic battery tester, multimeter, spare fan, Z-case fuse, CAN bus block, and the usual tools. Get to his house and it's just barely under 100F. No shade to work in. This is elderly abuse. Brother offers water. I decline, since wife packed up two thermos' with ice water and a couple plastic bottles for the drive. Peeing was more on my mind.

Brother suspects it's the aftermarket fan controller. He thinks we should remove it. I have no reason to argue. Since I've installed a few of these and removed one other, I'm elected for the labor. It didn't go quite as fast in 100F as the last one I removed in the cool of winter. Got the PCM wiring back to original configuration. Started it, and the fan came on. Not a big surprise. Took it for a drive and the fan was working fine running off the PCM control.

Brother wanted to look inside the Fan Controller that has been on for about a year now, under previous ownership.

@roaniecowpony , any chance you could post some uninstall steps for those of us who might get stranded? I did put a bunch of dielectric grease, then use liquid electrical tape to seal the connectors. And finally wrapped the interface with electrical tape to try and protect the unit.

 

[ASSFROW]

@THAW
Interface harnes? Do tell, please.

I ask because, being interested in the PCM fan controller but also being cognizant of the required wiring work, I reached out to Jon Schaefer at RPM Extreme last year to inquire about a plug-and-play harness. This is the response I received:

"There is no other location to access the wires needed that we could use a T-style plug in connector.

The ECU is the only place where all the wires are in one location and easily accessible. Splicing in at the ECU is the best way."

I Invented A Jeep Mod Doohickey

 

[roaniecowpony]

@roaniecowpony , any chance you could post some uninstall steps for those of us who might get stranded? I did put a bunch of dielectric grease, then use liquid electrical tape to seal the connectors. And finally wrapped the interface with electrical tape to try and protect the unit.

Those are the very same steps I took on the fan controller on my jeep. It lasted about 2 years. Jon opened it up and said it had evidence of moisture and dirt. I always had plans to put it in a weatherproof enclosure, but never got around to it. My thinking now is to just put it in the cabin under the dash and extend the wires.

As for uninstall, in the two instances I've done it, my intent was to remove it from the system. So, I pulled the PCM connector, unplugged the AC sense wire that branches from the PCM harness, and fed the harness thru the area nearer to the fender to get more slack, then unwrapped the tape and cut the tapped wires off of the PCM wires, cut out the resistor, and re-soldered the fan signal (purple/brown?) wire. In a pinch, you could simply unplug the module , unwrap the PCM harness, cut the resistor between the Blue/Red wire and the Brown/Violet, then re-join the Brown / Violet wire ends that were cut during the original installation. Having a copy of the installation schematic in the vehicle will help you understand these steps.

 

[ScotM]

Those are the very same steps I took on the fan controller on my jeep. It lasted about 2 years. Jon opened it up and said it had evidence of moisture and dirt. I always had plans to put it in a weatherproof enclosure, but never got around to it. My thinking now is to just put it in the cabin under the dash and extend the wires.

As for uninstall, in the two instances I've done it, my intent was to remove it from the system. So, I pulled the PCM connector, unplugged the AC sense wire that branches from the PCM harness, and fed the harness thru the area nearer to the fender to get more slack, then unwrapped the tape and cut the tapped wires off of the PCM wires, cut out the resistor, and re-soldered the fan signal (purple/brown?) wire. In a pinch, you could simply unplug the module , unwrap the PCM harness, cut the resistor between the Blue/Red wire and the Brown/Violet, then re-join the Brown / Violet wire ends that were cut during the original installation. Having a copy of the installation schematic in the vehicle will help you understand these steps.

Thank you! I do have the schematic in my off road repair pack

 

[roaniecowpony]

Thank you! I do have the schematic in my off road repair pack

I carry one of those little butane soldering irons in my electrical kit. The more I'm around these JLs, the more I'm inclined to think a full electrical repair and diagnosis kit is at least as valuable as a socket set.

 

[ScotM]

I carry one of those little butane soldering irons in my electrical kit. The more I'm around these JLs, the more I'm inclined to think a full electrical repair and diagnosis kit is at least as valuable as a socket set.

Funny you should say that……

 

[roaniecowpony]

I always have JSCAN and a meter too.

 

[ScotM]

I always have JSCAN and a meter too.

Those I do not have in my bag, thanks!

 

[ScotM]

Still have the unit mounted in the engine bay

 

[HHGadget]

Asking again in case my first time was missed.
Can this block be potted like the axle locker sensor….?

 

[ScotM]

Asking again in case my first time was missed.
Can this block be potted like the axle locker sensor….?

I called RPM Extreme, and they felt that as long as the unit is installed in the correct orientation all should be well. I was calling to see if if putting it inside an IP67 rated box would be ok from a heat generation perspective, and they didn’t seem to have a problem with that. They said the unit does not generate much heat to be concerned about. At this point I’m just in a holding pattern until @THAW solution is marketable, then I’ll decide next steps. You may want to tag rpm extreme about potting it

 

[dstevens]

To be clear this is 100% from water. It's not heat or abuse or anything else. I see this all the time.

Asking again in case my first time was missed.
Can this block be potted like the axle locker sensor….?

Possibly. The potting material has to be non-corrosive to electronics and also the electronics has to run cool enough that removing any convection cooling will not cook it.

But unless the connector is waterproof (ok, IP whatever) then as soon as you get voltage and water it will corrode to death surprisingly quickly. A week perhaps if it stays wet. The galvanic cell made between connector pins is pretty powerful.

I've designed and manufactured IP65 enclosures and it is more difficult than you think. IP65 is much easier. But you need to start with a appropriately rather connector and wiring harness.

And if you place the electronics inside the vehicle then take care to loop the wiring as well as sealing it. It is easy for water to get in a bundle of wires and run down the cable assembly inside the vehicle, which kills the electronics just like it would in the engine bay.

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