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Unread 11-27-2011, 04:21 AM   #16
KoreaZJ
Registered User
1994 ZJ 
 
Join Date: Aug 2011
Location: GANGNAM STYLE
Posts: 2,666
White with a yellow stripe???

That explains why I couldn't find a "WHITE" wire!

The "WHITE" (WT/YL) wire might be an override signal to swing the blend door to the full hot position. At least your blend door moves. It may be lacking signals from the dash control.

You can verify the wiring to the dash control by measuring at the blend door actuator connector.

With the ignition key off...
Pull connector from blend door actuator connector.
Should have 4 wires in pins 1-4 (pins 5&6 unused)
Connect ohmmeter across wires colored DB/RD and VT/WT. (pins 3&4, or center two pins of 6)
Rotate the temp control between cold/hot.
Ohmmeter should read near zero in one direction, higher in the other direction.

If this circuit is open, the temp control pot is either bad, or a broken wire, open connection in the dash control, etc.

All the parts are close together. Should be able to check for continuity between the blend door and dash controller on wire colored DB/RD, and then on VT/WT.

You can also pull the connector off the dash control, then do the same test to check the pot in the dash control. Same wire colors.

For your smoked pins...

The smoked pin in the corner of the connector should have been wire color DG to the dash control on one side, and BK to ground on the other side.

The smoked pin, second from the end, should have been wire color BK/TN. Provides the motor speed control, either a direct ground to the motor on HI speed, or through the resistor block for non-HI speeds. If the blower motor shorted out with the switch in HI fan speed, that would short +12v to ground, warm up the wires, then blow the 40amp fuse in the PDC. 40amps is heavy duty, might also want to look inside the dash control for damage.

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Unread 11-27-2011, 04:35 AM   #17
Degra101
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2007 JK Wrangler 
 
Join Date: Jan 2011
Location: Vancouver, Washington
Posts: 166
Quote:
Originally Posted by zachjf View Post
Welcome to the GC crappy heat club! Mine blows lukewarm air as well which is just plain awesome in 30degree oregon weather,
I have the opposite ! My GC has been the best car i have ever owned when it comes to turning on the heat. Itll nearly burn your hands coming out at full speed !
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Unread 11-27-2011, 03:33 PM   #18
zachjf
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1998 ZJ 
 
Join Date: Jun 2008
Location: Portland, Oregon
Posts: 1,067
Quote:
Originally Posted by Degra101 View Post
I have the opposite ! My GC has been the best car i have ever owned when it comes to turning on the heat. Itll nearly burn your hands coming out at full speed !
I just picked up a new thermo so hopefully that'll get my coolant temp up where its supposed to be, that doesn't work I'll tear the dash out, either way this POS is gonna heat up like it should!!
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Unread 11-28-2011, 10:59 AM   #19
digitalWJ
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Join Date: Jan 2011
Location: Davison, MI
Posts: 38
Quote:
Originally Posted by KoreaZJ View Post
White with a yellow stripe???

That explains why I couldn't find a "WHITE" wire!

The "WHITE" (WT/YL) wire might be an override signal to swing the blend door to the full hot position. At least your blend door moves. It may be lacking signals from the dash control.

You can verify the wiring to the dash control by measuring at the blend door actuator connector.

With the ignition key off...
Pull connector from blend door actuator connector.
Should have 4 wires in pins 1-4 (pins 5&6 unused)
Connect ohmmeter across wires colored DB/RD and VT/WT. (pins 3&4, or center two pins of 6)
Rotate the temp control between cold/hot.
Ohmmeter should read near zero in one direction, higher in the other direction.

If this circuit is open, the temp control pot is either bad, or a broken wire, open connection in the dash control, etc.

All the parts are close together. Should be able to check for continuity between the blend door and dash controller on wire colored DB/RD, and then on VT/WT.

You can also pull the connector off the dash control, then do the same test to check the pot in the dash control. Same wire colors.

For your smoked pins...

The smoked pin in the corner of the connector should have been wire color DG to the dash control on one side, and BK to ground on the other side.

The smoked pin, second from the end, should have been wire color BK/TN. Provides the motor speed control, either a direct ground to the motor on HI speed, or through the resistor block for non-HI speeds. If the blower motor shorted out with the switch in HI fan speed, that would short +12v to ground, warm up the wires, then blow the 40amp fuse in the PDC. 40amps is heavy duty, might also want to look inside the dash control for damage.
Thanks for the insight, this is leading me to think that maybe I may have messed up the controls when the wires touched during the wiring. The shop explained that they did test the voltage with their meter and they explained that the voltage was dropping when they would play with the heat controls. But maybe they were just checking the blower speed. I wonder if I go to a junk yard and pickup a new HVAC controller if it will fix the issue.

I'll have to keep playing around with it to figure this out.

The wiring is all done correctly where the wires in the melted connection are wired into the corresponding wire it was supposed to go into.

This information definitely helps though! Funny that they have a white/yellow wire that is sort of a backup for heat?

I wonder if it will matter if I get a digital HVAC unit or a manual unit to plug in.
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Unread 12-01-2011, 05:34 AM   #20
peter_zabriskie
Registered User
1997 ZJ 
 
Join Date: Jul 2008
Location: Santa, New Mexico
Posts: 39
Quote:
Originally Posted by KoreaZJ View Post
White with a yellow stripe???

That explains why I couldn't find a "WHITE" wire!

The "WHITE" (WT/YL) wire might be an override signal to swing the blend door to the full hot position. At least your blend door moves. It may be lacking signals from the dash control.

You can verify the wiring to the dash control by measuring at the blend door actuator connector.

With the ignition key off...
Pull connector from blend door actuator connector.
Should have 4 wires in pins 1-4 (pins 5&6 unused)
Connect ohmmeter across wires colored DB/RD and VT/WT. (pins 3&4, or center two pins of 6)
Rotate the temp control between cold/hot.
Ohmmeter should read near zero in one direction, higher in the other direction.

If this circuit is open, the temp control pot is either bad, or a broken wire, open connection in the dash control, etc.

All the parts are close together. Should be able to check for continuity between the blend door and dash controller on wire colored DB/RD, and then on VT/WT.

You can also pull the connector off the dash control, then do the same test to check the pot in the dash control. Same wire colors.

For your smoked pins...

The smoked pin in the corner of the connector should have been wire color DG to the dash control on one side, and BK to ground on the other side.

The smoked pin, second from the end, should have been wire color BK/TN. Provides the motor speed control, either a direct ground to the motor on HI speed, or through the resistor block for non-HI speeds. If the blower motor shorted out with the switch in HI fan speed, that would short +12v to ground, warm up the wires, then blow the 40amp fuse in the PDC. 40amps is heavy duty, might also want to look inside the dash control for damage.
I have a '97 ZJ and also looking to improve lukewarm air. Thanks for the insight and to the other poster for the schematic.
To the ZJ owner with the melted plug.....I would sure go looking for the cause of the melt-down before reconnecting the wires direct and running it again. You will repeat the melt-down possibly with worse (fire) effects.
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Unread 02-10-2013, 02:48 PM   #21
tonysaprano
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2002 XJ Cherokee 
 
Join Date: Nov 2012
Location: smthfield, va
Posts: 5
I realize it's been awhile since the last post but the info was excellent. My daughter has a 97 JGC (using it to drive to school 2 mi away)
It's in good shape and I restored a few items to bring it back to life.

Anyway, After looking and searching on the net. This post helped zero in the intermittent problem with the fan.
I purchased a small dc amp meter for 24 bucks to see what the fan was pulling. At high speed it was 12amps.
Nothing to write home about and nothing to show how the connector burnt the pins. I suspect that water
from the intake got into the fan and cause the higher amps. Actually, the pass side floor was flooding when it rain
hard and I removed the cowling and coated the rubber ring around the intake with silicone caulking. This stopped it

I cut the connector pin 1 (black and green wire) and used a 20amp inline fuse link from AAP and used a buttsplice.
Hopefully, if the fan every pulls excessive amps again. It will blow the 20 before smoking the whole wiring system.
I want to thank everybody for the great posts that helped me zero in the problem fast and get her jeep back on the road
again.
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