Replacement HVAC wiring harness?

Same problem blower motor not coming on at all. I replaced the fan speed switch, hard wired it because the pigtail was melted, replaced resistor and blower motor relay. Checked fuse number 8 under the dash, not blown. Pulled the blower motor tested it by using alligator clips and the battery, it kicked on. My next step is to check the wiring harness to see if I’m getting power to the blower motor but I figured it would save time just to replace it or them. I’m not sure how many wiring harnesses tie in together but I figured save time testing them and just replace it. I am not sure where to start on replacing it though. AND before I do that I just want to make sure I’m not missing something obvious.
 
I’m having the same problem. Replaced the blower motor blower motor resistor and the ac control panel. Worked then stopped. Did the thing everyone said on here with the spade connectors worked then went back to start it up and head to the store doesn’t work again. I noticed corrosion in the wiring how do I change that out.
 
thecraftieokie said:
I’m having the same problem. Replaced the blower motor blower motor resistor and the ac control panel. Worked then stopped. Did the thing everyone said on here with the spade connectors worked then went back to start it up and head to the store doesn’t work again. I noticed corrosion in the wiring how do I change that out.
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Same issue as me, I think my issue is in the wiring harness. Not sure if this is true or not but I’ve been told you basically have to remove the dash to get the wiring harness. I have thought about adding a switch from the battery to the harness and selecting one speed, probably speed #3 then running it to the blower motor. Just know if done like this don’t forget to switch off the blower motor after shutting down the jeep. Sorry I could be of much help but I’ve basically done the same steps you have with no luck.
 
Jod0001 said:
Same issue as me, I think my issue is in the wiring harness. Not sure if this is true or not but I’ve been told you basically have to remove the dash to get the wiring harness. I have thought about adding a switch from the battery to the harness and selecting one speed, probably speed #3 then running it to the blower motor. Just know if done like this don’t forget to switch off the blower motor after shutting down the jeep. Sorry I could be of much help but I’ve basically done the same steps you have with no luck.
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Not sure exactly which harness you are referring to but there is one behind the glove box. You don't need to remove the dash to get to it. I completely replaced all of the hvac wiring without removing the dash

Remember that the voltage thru the switch and resistor is the ground side of the circuit (12v-). The 12v+ side is direct from the engine fuse box to a relay then direct to the blower motor. The relay energizes and you will have 12v+ at the blower when the key is switched on, regardless if you have the HVAC on or not.

Not sure exactly which harness you are referring to but there is one behind the glove box.
 
I am referring to the harness that plugs into the fan speed switch on the climate control panel. If I had to guess there is a short in it somewhere. Blower motor works, replaced the relay, resistor, fan speed switch and verified the fuse was not blown. The only thing I have not replaced is the entire panel itself. I think the issue is the harness because the pigtail at the fan speed switch melted. I cut it off and wired it independently to each prong of the new switch as done in previous post in this forum. This would be great if replacing the harness was relatively easy to get to.
 
CreepinDeth said:
Nice job insulating the connections
Open bare metal connections will corrode quickly
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I am glad I paid attention to this thread, just replaced the 3 prong pig tail with the independent connectors and now the blower motor turns on. I have been chasing this issue for 6 months, it stop blowing about a year ago. Could not drive it to work in the winter because the windshield could not defrost and I was not about to scrape the ice. Now I just wonder how long it takes to melt those connectors but I have comp and collision so if it burns to the ground I’ll get a few “dollarbucks” for her.

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Jod0001 said:
I am glad I paid attention to this thread, just replaced the 3 prong pig tail with the independent connectors and now the blower motor turns on. I have been chasing this issue for 6 months, it stop blowing about a year ago. Could not drive it to work in the winter because the windshield could not defrost and I was not about to scrape the ice. Now I just wonder how long it takes to melt those connectors but I have comp and collision so if it burns to the ground I’ll get a few “dollarbucks” for her.
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the fix has been good for two years
 
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