Hi there I have a problem on my dash heater controls and want to change the unit, I have found a unit but the number of the part is the same but the 2 letter ending is different, the people I want to get it from can't confirm if it is ok to work. The number on my unit is. P55115903AE. The unit im looking at is same number but ends in AC. Can any one advise if they know if the new unit will work?

Many thanks if you can help.
Paul Compton.

Hi Paul, What happened that made you conclude that the controls are failing? I only ask because I almost "shotgunned" (replaced) same but found something else while poking around.

I'm not a 100% sure it's that, it was a toss up between that and resistor box. But I changed that less than a year ago, I'd switch the blower on and it was delaying before it would start unless I put it on high mode.

FWIW - I think you might do well to go at the box again. Inspect wiring for evidence of heating - especially 12-gauge red wire - where it enters the back-side of the 3-wire connector, unplug the 3-wire connector and inspect the connector face for evidence of melting plastics. If it's what I'm thinking then it may look like what is shown in these images.

I understand that you replaced the module/resistor a year ago but that may not have been enough. It may be too late for the replaced module as-well. The wires, connector and contacts also get compromised by excessive current draw and will need replacement. If you did find any evidence of the melting I showed you then you will need the replacement kit(s), two are shown in this image (you can see the P/Ns on the packaging and on the receipt). NOTE that your fan and ducts may have debris inside that make the fan work harder to move air, thus drawing more current, which causes heating of the wires & controller module (aka resistor). Remove three T25 Torx screws and the connector to drop the fan unit for a cleanout. Also be-advised that if you do get the kit, the 2-wire fan harness comes mis-wired (right out of the box). You will need to swap pins 1 & 2 at the fan end else your fan will rotate backwards (which sucks after dropping $120.00).

You know, I feel foolish for not asking the first most basic questions. Without knowing, I may be giving you bad info. Please update your profile and/or describe your Jeep model and year along with the type of climate control system. Does your model have the Manual Air Conditioning System controls or the Automatic Zone Control System? My Jeep is a 2000 with the AZC System...these kit P/Ns are specific to that.

Thanks for all that, that's the great thing about this forum great info. It has actually worked out to be the full resistor box again it has failed and is sorted inside. I've contacted the seller to try and get a refund on the item. It actually flattened the battery were it had sorted out. What a pain huh.

Paul, really, I didn't want to be right about this. But if you replaced the box without repairing the wiring AND cleaning out the fan/ducts then you'd be wrong to ask for a refund on the box a year later. In a lot of cases you can get away with plug-and-play but many electrical items usually come with a "no refund" policy for "cause and effect" reasons, such as misdiagnoses and incomplete peripheral repairs.

I'll see what is said. Fan was cleared out but not wiring changed. The us a two year warranty. I'll have to keep my fingers crossed. Thanks again for all that info. I'll look into new loom at same time I think. Are all supplied looms wrongly wired ?

USUALLY a cooked fan module plug is the result of the fan drawing too many amps because of worn bearings or bad brushes. I my opinion, you should replace the fan motor as well.

And that's all I'm going to add to this matter.

I have a manual control, and previous own supplied th wooden looking benzels for everything inside, one of wich comes with the auto control for the climate , (05 wk rocky moutain) what else needs to change to use the azc vs manual?