Radiator Fan/AC Problems

[Frommy]

So I replaced my cracked radiator this weekend. Everything went well, no more leaks! But I forgot to to do something... I didn't put the wires in the guides located on the edge of the fan. Basically the two power lines to the radiator fan were dangling (they are actually grouped together in a sheath).

I was driving it back home from my dad's (where I did the work) earlier today. It's about a 2-hour highway drive and in Ohio today it got pretty toasty. I turned on the A/C and the air was not very cold. In fact, I had to roll down the window so I wouldn't sweat to death . After arriving in Kentucky, I checked the engine to make sure I wasn't having any issues. Low and behold I see the two lines coming from the fan laying right next to the pulleys and belts. I'm lucky the lines didn't get tangled in the belt and cause serious damage. The lines definitely came in contact with the belts. The sheath is torn in a couple spots, there are also a couple spots where the two wires are now exposed. There doesn't seem to be any disconnections between the wires. BUT the fan doesn't spin. I believe this is related to my A/C not getting cold? I turned on the Jeep and cranked up the A/C...no fan spinning.

I don't believe there is an easy way to replace the power cord to the fan because it is directly attached to the fan motor. Do you think I should try splicing the cable and take out the sections of exposed wire? Anything else I should test/check to see if the fan will work?

I'll try to upload a pic tomorrow. THanks!!

 

[Ry' N Jen]

Well gee...
I guess you should of clipped the wires into their little holders Eh?

 

[Frommy]

Wow...have you ever heard the term hindsight is 20/20?

Anyway, I wondered if anyone has spliced the radiator fan wires before.

 

[ptsb5a]

I've never spliced 'em but seeing as it's a 12Vdc cct, simple splices (crimp or solder) of the appropriate gauge should suffice.

Ryan, take it easy dude. Everyone makes mistakes. Like forgetting to clip something back in, wrap something up or getting married too young.....

 

[kb0nly]

Get some tape, tape everything up, if the areas where the wires are exposed aren't that big a couple layers of tape around each spot then tape up the whole thing, no worries..

The wires getting rubbed on by the pulleys probably shorted the positive and blew the fuse. Check the radiator fan fuse!

 

[ptsb5a]

Hey kb, if tape is good enough, I've got a couple of rolls of Kapton wiring for ya. Tape gets brittle and breaks. The fan cct has a 40A fuse protecting it. I personally wouldn't trust tape to protect it. I'm no engineer but have been an aircraft electrician for 19 years. If the tape is 3M Super 88, it'll hold for a while, otherwise, Amphenol and Raychem make splices safe for use with that sort of current.

 

[Corwyyn]

And I was just wondering this past weekend as I was finishing up installing my new radiator what the consequences of leaving those wires loose would be...

Since the plastic stub on the connector was a bit worn I drilled another hole in the fan shroud right next to the mount point for the connector and put a tie-wrap around it to make sure it stayed in place.

 

[Ry' N Jen]

Ya ya ya...
Call it my sense of humour!

 

[Frommy]

So where exactly is the radiator fan fuse located?

 

[LibertyTC]

Use heat shrink tubing put ahead of wires but don't seal it, until it is known to be working again. Probably in block under hood, and relay is located slightly ahead of battery located on side of fender about a foot down in middle.

 

[kb0nly]

Hey kb, if tape is good enough, I've got a couple of rolls of Kapton wiring for ya. Tape gets brittle and breaks. The fan cct has a 40A fuse protecting it. I personally wouldn't trust tape to protect it. I'm no engineer but have been an aircraft electrician for 19 years. If the tape is 3M Super 88, it'll hold for a while, otherwise, Amphenol and Raychem make splices safe for use with that sort of current.

The tape is just a temporary fixed granted, but he was asking how to figure out what was going on. So i guess i should have made myself more clear here, geesh...

Tape it up, check the fuse, and make sure everything is working. No sense in spending an hour and making nice splices and replacing it all and then finding out the fan is bad.

As for the tape becoming brittle and breaking... Use better tape. I have 3M Super 33+ on some cables thats been there for about 8 years and its still soft and pliable.

In the OP's case, once you know you got it working and there is no other problems cut the wires on either side of damage, splice in some new wire, solder and glue lined heatshrink tubing is what i prefer, but you can also use some 3M marine rated butt splices, they have a glue lined heatshrink sleeve on them, crimp, heat, and forget. Then cover the whole works with some new split loom tubing and a few cable ties to make it nice and neat.

 

[kb0nly]

Hey kb, if tape is good enough, I've got a couple of rolls of Kapton wiring for ya. Tape gets brittle and breaks. The fan cct has a 40A fuse protecting it. I personally wouldn't trust tape to protect it. I'm no engineer but have been an aircraft electrician for 19 years. If the tape is 3M Super 88, it'll hold for a while, otherwise, Amphenol and Raychem make splices safe for use with that sort of current.

Oh and Kapton wiring is ok if you keep it away from heat...

For the non-tech types on here, Kapton is the better-known DuPont brand name for a type of aircraft wiring known as aromatic polyimide. After prolonged exposure to heat the insulation becomes carbonized and it arcs... Makes a nice light show...

 

[Frommy]

I replaced the fuse. I couldn't tell if it was blown, so I replaced it anyway. I guess I was wrong this whole time. It seems the fan does work! It's a pretty hot day in Lexington (85 F) and as I watched the fan from my cab for about 10 minutes, it magically kicked on for about 30 seconds and turned off. So now I've come to the conclusion that the radiator fan is fine and my A/C is the culprit.

I guess a basic question is: Why is the radiator fan not spinning when the A/C is turned ON?

From what I understand the radiator fan should be spinning constantly while the A/C is turned on, and only occasionally when not using the A/C (just to cool down the radiator when idling). As of right now, I'm getting HOT air and NO radiator fan spinning while using the A/C.

I'm probably going to take it to a mechanic, but I'd like some pointers on what problems I should be looking for.

Thanks for all the input guys!

 

[ptsb5a]

Could be the A/C pressure transducer. It reports a pressure signal to the PCM and the PCM uses simple logic ccts, probably silly little OR gates to decide to turn the fan on. If the fan relay is good and the 40A fuse is good and the fan spins on it's own when the motor gets hot enough (one of the OR conditions) then using my own silly logic tree, we can safely surmise that perhaps it's the A/C pressure transducer. Maybe you need to have the A/C serviced.

 

[Corwyyn]

I guess a basic question is: Why is the radiator fan not spinning when the A/C is turned ON?

Because a couple of conditions have to be met before the fan will engage. From my '03 FSM (you can blame them for the questionable punctuation):
The relay is also energized when, air conditioning
is selected and coolant temperature is
above 95° C ( 203° F), or , air conditioning is selected
and battery temperature sensor is above 41° C (106°
F). It will then de-energize when , air conditioning is
selected and coolant temperature is below 92° C
(198° F), or , air conditioning is selected and battery
temperature is below 38° C (100° F).

So even if you have the A/C on if the coolant temp or the battery temp are not high enough to tell the PCM to turn the fan on it will sit and wait...

I agree with ptsb5a that you should have the A/C checked - since it is an '02 it could be something as simple as a leaking system that doesn't have enough coolant for the compressor to work properly, and the best way to find that out is to have a qualified person do some tests on it.