I was just out enjoying the nice cold AC that my new evaporator has brought to me, when all of a sudden everything goes and gets warm real quick. After verifying that the compressor was not engaged by the system, I first checked the system pressure, and then went to the fusebox.

I discovered that the "AC start" fuse was blown. I replaced the fuse, and attempted to engage the AC with no luck. Clutch would still not engage, and fuse remained intact. I remembered that many AC systems will not engage if there is a problem with the AC fan, so I looked behind the grille to discover that the fan disk itself was so loose and wobbly, it was stuck on the condensor and could not move. The fan motor was hot to the touch.

I next went in search of the fan relay, but did not find one, because this fan was a part from another vehicle that had been" installed" on this one by splicing the compressor clutch's leads, and wiring voltage directly to the fan, with no fuse or relay.

It was only then that it hit me that out of all of the Magnum-engined A/C Dodge vans, SUVs, and pickups I had seen at the pull-it-yourself sc rap yard, not one of them had an electric AC fan mounted in front of the radiator.

I'll get another good look real soon, because I likely have to go back there when they open in a few hours, so I can pull a compressor clutch.

I'm better than this. I know I'm better than this.

 

Yes that a/c booster fan is not stock. Apparently Dodge did add an A/C fan on later model Dodge pickups but not these.

I am having trouble figuring out how this would fry your fan clutch though. Even if the fan shorted it should only blow the fuse or melt the wiring. I assume you have already tried running 12v directly to the A/C clutch by now but if not, try that first.

Not all A/C clutches can be removed without specialty tools. Standard pulley removers usually will not work. If someone else has specific knowledge about this (TRF-105 Sanden) I would love to know.

 

No, I had not yet done so. I was just figuring it was probably dead. I ran 12v straight to it (after disconnecting teh ghey fan) and it came right on. Turns out that the whole bit overheated the AC compressor clutch relay, and the whole bit started working properly again as soon as it cooled down.

Clutch and system are back working again, and I am back to freezing my *** off.

Still, this will serve as a reminder for future operations.

 

Cool. Literally, in this case

 

I see now why somebody tried to add a booster fan. This system is alot colder when it has some good airflow over the condenser. I'll have to take their wiring, and hook it up to a proper relay and a new high-flow fan to help improve the AC's performance.

Might replace the AC relay, just in case.

 

For future reference the better way to accomplish the task of consistently cold A/C is just to replace the existing water pump / serp belt driven fan assembly with an electric puller fan. Most electronic fan controls have an A/C circuit that runs the fan constantly when the compressor is switched on. Plus, you'll pick up a few MPG and make the front bearing in your water pump last for like a billion years.

Well, maybe not for that long, but for a very long time.

 

Unfortunately, for that kind of mileage you need a Ford van.
http://www.millionmilevan.com/

 

I haven't done anything yet. I just might go ahead and do exactly that. It's easier to put a fan on the back, than to add one to the front anyway. I will check the radiator dimensions to find a suitable fan.

I have to go digging around in there anyway to replace my tensioner pulley. I might just do the fan at the same time.