Jeep Enthusiast Forums banner
1 - 20 of 75 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
Hello, I first of all apologize if somewhere this question has been posted but I couldn't not find one specific to what I am about to ask. if its out there send me a link please.

Currently my 1999 jeep grand Cherokee limited has a weak blowing air conditioner/heater. I recently replaced the blower motor resistor as it was warped and not working properly. After doing so it seems the air system blows very weak out of the vents. Barely enough output to cool/heat the inside after an hour. I also cut and accessed the blend doors and the driver side blend door is broke but seals in the downward position for AC, passenger side works fine, but even when driver side is wedged down tight the AC still was blowing weak. I also removed the blower motor and turned it on outside the housing and it appears to be blowing pretty strong.

So considering all the above does anyone have any experience with this problem or have any suggestions to help? Thanks!
 

·
Registered
Joined
·
3 Posts
Discussion Starter · #3 ·
Ahhhh, I was wondering! I found somewhere to reverse the wires and I did but they were the wires to the resistor causing the fan to blow full at all times even with the key off lol. I didnt think to reverse the fan ones. It was making it blow much stronger though although I couldn't stop it. Thanks, that will do the trick. Why is it reversed anyway? Thanks again.
 

·
Registered
Joined
·
6 Posts
Switch heater fan wires

I read this and weep! I have chased this issue for over a year off-and-on. Blend doors. mode doors, resistor,etc. etc. Fixing the resistor really screwed it up. Reversed the wires on the fan and now FULL blow with control! :cheers2:

I can still say that the passenger side vents next to the air bag don't blow hard...or almost at all .
 

·
Registered
Joined
·
6 Posts
You can't see it without pulling it. There is one screw next to the outerwall that has lots of wires in the way. It is MUCH easier to just pull the plug out of the bottom of the motor, cut and reverse. Make sure you have done/checked the blend doors, and if you drop your glove compartment door you can physically see the outside/recirc door move in the grill.

Remember everything else worked...it just didn't blow hard... I had lots of codes that I thought were new....but weren't. That faked me out also. When I got rid of the codes "per the book" then there was nothing to do except find something physical...or this fix.

I WAS going to make myself prove it and take the fan out...I'm having a beer now instead! :cheers2:

(You have probably done this by now....I'll bet!)
 

·
Registered
Joined
·
229 Posts
....It is MUCH easier to just pull the plug out of the bottom of the motor, cut and reverse....
You don't have to cut anything to switch them. Just swap the wires in the connector.
If you have a precision screwdriver set, just take one of the small flat-heads and on the bottom of the connector you'll see a piece of blue plastic. Pry the blue piece out from the side. It comes right out.
Then in the same place where the blue piece was, jam the screwdriver in between the metal of the wire and the plastic of the connector in the middle.
Tug and the wire will come right out. Same for other wire. Then swap the two and push back in till you can feel them click into place. Push the little piece of blue plastic back in the middle and that's it. Plug back in and done.
 

·
Registered
Joined
·
2 Posts
Oh my gosh, I'm really hoping this is my problem. I have a 2002 GC Overland and I'm wondering if it's the same resistor as the 1999 model? I'm not sure which wires you are talking about since there were no pictures. My fan started failing sporadically then stopped working eventually, no hot or cold on any speed, so my mechanic just replaced the blower motor resistor and showed me the old as it was obviously melted. However, now I hear the blower running extra hard (seems louder than before) but I'm getting barely any air out of vents. Also, it is dual climate with auto temp control as well, not sure if that makes a difference?

I've seen the posts on blend doors, recirc door and all that...but I just don't feel it's that. I can see the recirc flap moving in and out, and I have both cold and hot air, so I don't think it's blend doors...it's just not even 1/3 as powerful as it was before. He said it's probably blend doors and that they need to take dash apart and replace probably, but he couldn't tell before taking dash off...which costs about $600 in labor alone, and I already had them replaced about 5 years ago for $1k. I'm just not convinced it's that because of the hot/cold/recirc thing....and the symptoms sound exactly like this. I've been hunting on this site for days and this is the first thing that sounds like a match.

Is reversing the wires also applicable to the 2002 grand cherokee? Just find the ones going to the blower and switch those? Which are they? I don't have the one he took out and haven't seen the fins on the one in there...so I can't say as to size difference. I also was debating cutting a hole in back of the glove box to verify the blend door operation, but this seems that it can avoid that altogether since all the blend and recirc seem to work fine to me. But maybe I need to? I also read about that blend door kit that you use a dremel to cut and replace without taking out the dash, but I hope I don't have to go there.

Does any of this sound familiar?

I'm new on the site and don't do nearly as much work myself as everyone on here, but get a lot out of the site for troubleshooting. So thank you for any help you can give!!
 

·
Registered
Joined
·
831 Posts
mb2paw... if that's not it,
double check your recirc door. Check your AZC codes and post them up. Check for evap freezup and drain blockage. there's another post on here that sounds similar and it's possible with warm humid weather you are icing up. Remember the AZC will engage the AC at any time it feels it necessary, and may not illuminate the AC light when doing so in auto mode.
 

·
Registered
Joined
·
170 Posts
MB2PAW: If you have low air flow from all vents I had that same issue after I replaced my fan blower resistor with the upgraded kit. As it comes from the factory, the 2 wire plug (green/black wires) are reversed! and cause the fan to spin in the wrong direction! All you need to do is swap the black and green wire orientation on the plug. I did it on the end that plugs into the fan. If you unplug that 2wire from the fan you will see some black tabs that need to be pressed in, then you can pull out the wires. Just swap their orientation and you'll be good to go.

I also seem to have air leakage in the vent ducts. Apparently there is supposed to be foam seal at some connection points but mine has fallen apart somewhat. Apparently it's a huge job of removing the dash to get at the vent duct work.
 

·
Registered
Joined
·
170 Posts
Guys no need to do a slice job on the wires. Just inspect the black 2 wire plug that goes into the fan. There are small tabs that you need to press on and the wires will come out. That's much easier than a slice and splice job.
 

·
Registered
Joined
·
2 Posts
OMG, you guys are amazing!!! You just saved me $800ish dollars! You were exactly right with the green and black wires miami5th, I just used the technique you guys mentioned and was able to just pull the wire connectors out and switch them, no need to cut and splice. I have FULL power air and I'm so happy right now. A little upset at my mechanic that he was ready to take my dash apart just to troubleshoot this, so I think it's time to part ways.

As for the AZC codes, they were alternating 52 and 54, which is blend doors....but I'm wondering if that's just never been cleared out from when they actually were broke 5 years ago? Is there an easy way to clear those?

Again, thank you to the OP and everyone who replied, SO helpful!!!
 

·
Registered
Joined
·
170 Posts
Anytime mb2paw! I'm just paying pack some of the helpful info that I've received from other forum members. I also have a 52 and 54 fault code but my blend doors work just fine, I visually inspected them and saw them travel up and down and I have full control of hot/cold temp settings. I think it might be an old fault and it should clear the next time it does the calibration test or if you unhook the battery for like 10min.
 

·
Registered
Joined
·
107 Posts
Ahhhh, I was wondering! I found somewhere to reverse the wires and I did but they were the wires to the resistor causing the fan to blow full at all times even with the key off lol. I didnt think to reverse the fan ones. It was making it blow much stronger though although I couldn't stop it. Thanks, that will do the trick. Why is it reversed anyway? Thanks again.
can anyone take a pics of the wires you guys are talking about thank ?
 

·
Registered
Joined
·
107 Posts
I read this and weep! I have chased this issue for over a year off-and-on. Blend doors. mode doors, resistor,etc. etc. Fixing the resistor really screwed it up. Reversed the wires on the fan and now FULL blow with control! :cheers2:

I can still say that the passenger side vents next to the air bag don't blow hard...or almost at all .
can anyone take a pics of the wires you guys are talking about reverse the wires on the blower? thank
 
1 - 20 of 75 Posts
Top