No power to blower motor? What's the issue? - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Like Tree1Likes
  • 1 Post By RUBI 4 MY MRS
Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 07-31-2015, 08:28 AM
Thread Starter
  #1
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
No power to blower motor? What's the issue?

Hey, so I recently bought a 1999 TJ Sahara, and I've been having trouble with the blower motor. The guy I bought it from said I needed a new one, so at first I thought that was all, but I pulled out the motor, it spins freely, wiring it to the battery on its own it works, so it's not the motor. So I checked the resistor. It's fine. Looks a tad rusty, but it's fine. Next I checked the fuses and the A/C relay. All are fine. Looked at the switches behind the dash. Two of them, the speed selector and the one off to the side of the vacuum hose switch thingy that controls which vents are used, each had a lead melted. I broke the melted lead out of the speed selector, cut off the burnt wire, and jerry-rigged a new blade connector in place of the old connector, so it should work. Nothing. I used a test light and figured out that there is power going to the fuse and through it, but nothing going to the resistor or the switches. Does anyone have a clue what's wrong with it? Do I have to rewire the whole HVAC system or something? Other than a broken wire somewhere I can't see, I don't know what it might be.

Agamemnon is offline   Quote
Old 07-31-2015, 12:11 PM   #2
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
If you didn’t fix the other melted wire that is probably your problem. More than likely that is the other end of the same wire you fixed at the speed switch. That would be a dark green wire.

You have no power at the resistor or switches because that is the ground side of the circuit. The only 12v power for the fan is to the motor itself.

Here is a complete diagnosis procedure for the circuit.

https://www.wranglerforum.com/f210/tj...l#post15939209
a4j likes this.

__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 07-31-2015, 12:17 PM   #3
Jeeper
 
Dextreme's Avatar
 
Join Date: Oct 2011
Location: Oregon City, OR
Posts: 8,397
Replace the whole switch where you found the melted connector. Its a common problem.

http://www.amazon.com/Jeep-Wrangler-...ywords=TJ+HVAC
__________________
'99 Chili Pepper TJ - I4 PowerTech motor
33x12.5 DuraTracs
Zone 4.25"
F8.8/Artec Rear
Dextreme is offline   Quote
Sponsored Links
Advertisement
 
Old 07-31-2015, 05:13 PM
Thread Starter
  #4
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
So the melted wire on this connector is the problem? I hope so, because I just tore it apart and I'm going to go ahead and rig something for this too.
Attached Thumbnails
Click image for larger version

Name:	image.jpg
Views:	468
Size:	165.6 KB
ID:	2381889  
Agamemnon is offline   Quote
Old 07-31-2015, 06:03 PM   #5
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
Yes, the wire to the middle terminal there goes to the speed switch & I’m betting that is the one on the speed switch that was melted. The switch may be bad but usually not. Be sure to insulate the terminals well if you replace that connector with 3 individual wires as many have done. They are very close together. I have seen 1 that used electrical tape & the heat melted it so not a bad idea to get some shrink tubing & use it on each terminal.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 07-31-2015, 06:05 PM
Thread Starter
  #6
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
Oops, wrong picture. Not important now anyhow.

So I followed those directions in that other thread, and I still have no clue what's wrong. I stripped/cut the melted crap off the dark green wire, jumped it to the ground wire, and nada. Tested the ground with a light, good ground. Tested each speed lead. Grounded. Tested each resistor connector lead. Grounded. The only thing I have yet to test is the blower motor wires themselves, though they look fine. That or the resistor, but if high bypasses the resistor, shouldn't I have that even with a bad resistor?

EDIT: I did exactly that with the shrink wrap, though it came undone on accident. Didn't solve my problem.

On that connector though, what on earth is the other (light) green wire for? That one isn't melted, but should it be connected to something for my tests?
Agamemnon is offline   Quote
Old 07-31-2015, 06:17 PM   #7
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
Make double sure you have a good ground when checking everything. If so & nothing works then yes, check the connections at the motor. You did check for power to the motor, right?

Yes the resistor is bypassed for high so grounding the brown/tan wire should ground the motor directly.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 07-31-2015, 06:25 PM   #8
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
The smaller light green wire is for the a/c compressor. It is also grounded through the bottom black wire when you are on a/c or defrost positions on the mode switch. Not needed for testing the fan just be sure it is on top & the black wire is on the bottom when you wire them up to the switch.

Make sure you are using small enough shrink tubing & getting it hot enough to shrink tightly to the terminals.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 07-31-2015, 06:28 PM   #9
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
I will add that usually the best ground to use when testing is that black wire from that same 3 wire connector. I think in that link I have you verify that it is grounded.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 07-31-2015, 06:39 PM
Thread Starter
  #10
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
I didn't test for power at the motor until now. What I'm seeing with the light is that one of the two connectors is a good ground and the other is nothing (it should be hot). This is with the key on. The fuse is good for sure, so what would cause no power between the fuse and the blower motor itself?

EDIT: I had that black wire jumped to the dark green one with two burnt ends for testing, so I ran a wire to the ground on the battery to make sure it was good for testing.
Agamemnon is offline   Quote
Old 07-31-2015, 06:50 PM   #11
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
OK, for ’99 the main power to the motor is from fuse 11(40a) in the PDC. That goes to the relay up near the resistor. Then when the key is on power to the relay coil is from fuse 8(10a) in the fuse block behind the glove box. The other side of the relay coil is grounded. Be sure to check f-11 with a meter because they have a habit of blowing where you can’t see the burnt spot. If good & you are getting power to the relay socket at terminal 30 you can jump across to 87 & the fan should run. Then if either slot 86 or 85 is getting power when the key is on (the other should be grounded) then the relay is bad.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 08-05-2015, 11:43 PM
Thread Starter
  #12
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
Hey, thank you so much for your help, I finally fixed it all. I made a new connector for the mode switch wiring out of female connectors I got at Autozone, and then used a wiring diagram to try to look for every possible issue. It turns out that I was looking at the wrong relay the whole time, the right one is behind the glove box like you said. Replaced it and voila!

However, now only the AC and defrost modes work - the two non-AC fan modes don't do anything at all. I'm guessing that's a vacuum leak somewhere? Also, the heat doesn't get hot and the AC doesn't get cold. Any ideas to troubleshoot those? Another switch? Maybe that variable resistance switch that controls the temp?
Agamemnon is offline   Quote
Old 08-06-2015, 12:21 AM   #13
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
You must have the wires on the mode switch in the wrong places. The small light green wire goes on top & the bigger dark green in the middle. The black is on the bottom. If you reverse the top 2 the compressor in on in all positions except off (but you probably wouldn’t notice that) & the blower only works in the position where the compressor is on which is a/c & defrost.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 08-06-2015, 11:20 AM
Thread Starter
  #14
Jeeper
 
Agamemnon's Avatar
 
Join Date: Jul 2015
Posts: 183
Oh, yeah, I put the black one on top and the light green on bottom. That makes sense now, thank you.
Agamemnon is offline   Quote
Old 06-18-2017, 08:51 PM   #15
Newb
 
Join Date: Jun 2017
Posts: 1
fan blower motor .. found melted wire

Okay .. I have the dreaded blower motor fail.
Blower runs fine for awhile and then shuts off on any speed and at any mode selection. I turn it all off and it will start back up just fine and run again and then shut down .. its like it is overheating and needs a cool down period.
Over the past 6mos of intermittent blower function, I have done blower motor, speed switch, relay, and resistor.
I live in Texas and it has been 100 here.
The blower gave completely out today.
I tore back into EVERYTHING beginning at motor side and going back .. no signal to motor and direct 12V test to motor and it works.
Fast forward to me pulling the HVAC control panel out, I decided to do it with ignition power on and fan control switch on in case of any loose connection.
As I am removing it, the fan is kicking on and off .. I find the dark green center wire is melted on the mode selector switch and having intermittent connection and has just gotten worse with time.
So I read where you guys are repairing this but my question is .. why is it melting down?
I do not want to repair this just to have a melt down again or burn something else up.
Thank you so much for any time and knowledge shared here with me.
Patrick
PTInvestments is offline   Quote
Old 08-16-2017, 03:59 PM   #16
Newb
 
Join Date: Aug 2017
Posts: 1
My issue ended up being the relay that is located behind the glove compartment. Simple to change and the cheapest part. Around $10. Hope this helps.
TJWrangler1999 is offline   Quote
Old 08-16-2017, 06:47 PM   #17
a4j
Jeeper
 
Join Date: May 2016
Posts: 149
Quote:
Originally Posted by PTInvestments View Post
......So I read where you guys are repairing this but my question is .. why is it melting down?
I do not want to repair this just to have a melt down again or burn something else up.
Thank you so much for any time and knowledge shared here with me.
Patrick
The fan motor draws a lot of current so it has a habit of damaging the resistor pack, wiring, and often the fan speed switch too. And fan motors can start going bad too where it starts drawing more current which will accelerate damage to those components. [Source: Jerry Bransford in this thread.]
a4j is offline   Quote
Old 12-23-2019, 11:57 PM   #18
Newb
 
Join Date: Nov 2011
Posts: 2
Quote:
Originally Posted by RUBI 4 MY MRS View Post
OK, for ’99 the main power to the motor is from fuse 11(40a) in the PDC. That goes to the relay up near the resistor. Then when the key is on power to the relay coil is from fuse 8(10a) in the fuse block behind the glove box. The other side of the relay coil is grounded. Be sure to check f-11 with a meter because they have a habit of blowing where you can’t see the burnt spot. If good & you are getting power to the relay socket at terminal 30 you can jump across to 87 & the fan should run. Then if either slot 86 or 85 is getting power when the key is on (the other should be grounded) then the relay is bad.
99 wrangler TJ 4.0L

I have power at 87... I have no power at 85 or 86 (both grounded)... Blower works when i supply power to 30 with power probe... I need to know what supplies signal to 85 or 86 that lets the power thru to the blower. Recently replaced heater core and everything worked before...

Maybe pinched wire in the steering column during reassembly?
Fuse 11 + 8 Good... Relay swapped and same problem...

I appreciate any help with this.
Justin259 is offline   Quote
Old 12-24-2019, 12:10 PM   #19
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
One of either 85 or 86 (usually 86 but not always) needs 12v power from fuse 8 when the key is on. If the fuse is good, always best to check with a meter to be sure, but no power to the relay you have a break in the wire between the fuse & relay.

For your ’99 it is a red/dark green wire & it goes to a couple other places in the HVAC circuit as it piggybacks to the relay. One is the blend door motor so see if it works or has power there. That might help isolate where the break is.
__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Old 12-24-2019, 02:48 PM   #20
Newb
 
Join Date: Nov 2011
Posts: 2
I bet you get this a lot... You were right. Installed new wire from back of Fuse 8 in the panel directly to 85 pin of the Blower Relay and I've regained blower control and as an added bonus my Blend Door Actuator is working again. Thank you for your help Rubi 4 My Mrs.
Justin259 is offline   Quote
Old 12-24-2019, 03:14 PM   #21
Jeeper
 
RUBI 4 MY MRS's Avatar
 
Join Date: Feb 2011
Location: Trails of Nevada
Posts: 3,391
Good work.

__________________


'05 Rubi TJ Unlimited
'93 Toyota 4Runner
RUBI 4 MY MRS is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off






All times are GMT -5. The time now is 05:07 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, Gladiator, Mopar and Grand Cherokee are copyrighted and trademarked to FCA US LLC.
Wranglerforum.com is not in any way associated with FCA US LLC.