Replacement HVAC wiring harness?

burdetter16

burdetter16

TJ Enthusiast
Joined
Mar 25, 2020
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110
Location
Tyler, TX
My A/C went out recently so I pulled the control module out today and found this melted wiring harness. I’ve looked every where and cannot seem to find a replacement one.

FDA54015-19B0-4599-AE8E-4480322E11C1.jpeg

This one looks similar but it says it doesn’t fit a tj: https://www.amazon.com/dp/B0049TTR6G/ref=cm_sw_r_cp_api_glc_fabc_Cwx0Fb3FENXZ6

Does anyone know where I can get this part? It’s from the far right side of the module behind the selector switch

8142B78A-D464-43ED-BC56-AADA2C85F822.jpeg
 
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burdetter16 said:
My A/C went out recently so I pulled the control module out today and found this melted wiring harness. I’ve looked every where and cannot seem to find a replacement one.

View attachment 209161

This one looks similar but it says it doesn’t fit a tj: https://www.amazon.com/dp/B0049TTR6G/?tag=wranglerorg-20

Does anyone know where I can get this part? It’s from the far right side of the module behind the selector switch

View attachment 209160
Click to expand...
This is the name of the connector you need.
712273FE-F8EA-46FF-9DBD-0A758ABF60FC.jpeg
 
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Skip the connector and crimp on some female spade terminals.pic isn't perfect but I have replaced the vast majority of my hvac wiring. If I remember correctly, those particular terminals require a .187" female spade. $4 for a box of 7 from the auto parts store

IMG_20200502_162038.jpg
 
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Jamison C said:
This is the name of the connector you need.
View attachment 209166
Click to expand...
Thank you
TrueTexas said:
Skip the connector and crimp on some female spade terminals.pic isn't perfect but I have replaced the vast majority of my hvac wiring. If I remember correctly, those particular terminals require a .187" female spade. $4 for a box of 7 from the auto parts store

View attachment 209170
Click to expand...
That’s a great idea! I was thinking I’d probably have to do something like that good to know it works!
 
burdetter16 said:
Thank you

That’s a great idea! I was thinking I’d probably have to do something like that good to know it works!
Click to expand...

The female spades work great. Just get the right size. I used a 16-14 gauge (Blue insulated) with a .187 female spade. Autozone and Advance Auto both stock them. Also, use a good quality crimper and just make sure you get them back on the right terminal.

I covered the middle one with heat shrink so there was no chance they could short to each other but once they are connected, there is almost no chance of that happening.

I really didn't like the design of the replacement connector. I think the female spades are a better choice. Plus, it is much cheaper.
 
@reigthe wiring is severely undersized and the high current is routed through the switch. Once the wires age, resistance increases and the unfortunate byproduct is heat - a lot of heat. The current draw of the fan requires a larger fuse, so the weak link fails.

Think of an incandescent light bulb. The filament is burning (albeit in a vacuum) but the breaker doesn't trip every time you turn the light on. That's pretty much what is happening here.

Note that the switch and speed control resistor are on the negative side of the circuit. The positive side is very simple, fuse to ignition switched relay to fan motor.
 
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@Reign Mack I started with the premise that the higher than normal current I was seeing was a problem with the blower motor. Replacing the blower motor w a new OEM one did not measurably reduce the current. I then built the low current circuit and relay array and also replaced the high current relay on the 12v+ side. Still had issues with the high current and excessive heat. Fortunately, it was limited to the high current side of the circuit so the control panel was safe. After a bunch of troubleshooting, I found the final wires leading to the blower motor itself to be severely corroded. I finally replaced the wires that went to the blower motor and now it works perfectly.
 
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@TrueTexas thanks for the info, my fix was a bit vanilla compared to that, I didn't know what the issue was at first so went through the motions of changing everything starting with the cheapest item, blower control -> heater resister -> motor -> control panel. That's when I realised the plug was melted and plastic welded to the old control panel.
 
I did not reuse the blower motor connector. I used new fully insulated spade terminals and put some dielectric grease around them to keep them sealed. I think I posted a picture somewhere on the forum
 
New to forum. I’ve had same issue and repaired using female spade connectors about three years ago. Recently I lost lower speeds on blower except for high. Replaced resistor, didn’t work, then replaced speed control still not working. Any thoughts?
 
Fishin said:
New to forum. I’ve had same issue and repaired using female spade connectors about three years ago. Recently I lost lower speeds on blower except for high. Replaced resistor, didn’t work, then replaced speed control still not working. Any thoughts?
Click to expand...

Fist guess would be the switch itself. Pull it, see if you can get voltage from all the settings.
 
hear said:
Fist guess would be the switch itself. Pull it, see if you can get voltage from all the settings.
Click to expand...

Discovered the culprit.
Fishin said:
New to forum. I’ve had same issue and repaired using female spade connectors about three years ago. Recently I lost lower speeds on blower except for high. Replaced resistor, didn’t work, then replaced speed control still not working. Any thoughts?
Click to expand...

hear said:
Fist guess would be the switch itself. Pull it, see if you can get voltage from all the settings.
Click to expand...

Discovered the culprit the plug to the speed control resister had loose connection. I was backtracking, left the ignition on with hvac switch in on position with fan speed set to lowest fan speed, as soon as I touched the plug it made a good connection and worked on all fan speeds. Now to try and find a replacement.
 
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