Hottest day of the year so far and my blower quits

B1Toad

B1Toad

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Went to a restaurant for lunch, everything was working great. came out and started the Jeep, no blower on any speed. Tried turning the key slightly back, tried re-starting engine, nothing. Will be starting troubleshooting probably in the AM, it's 104F out there right now and I can't get it into the garage, no room. Been searching old threads and printed out my wiring diagram. Looks like the relay trigger gets switched on at the dash thru fuse 8 and energizes the coil which feeds the blower motor from the 40 amp fuse in the PDC and the speeds are controlled by the ground signal routed thru the various resistor taps.

If it turns out I need the dash controls are the aftermarket ones any good or Mopar only?

edit: Correction, it's not 104F, it's 106F.
 
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Hell I'd just pull the battery to get to the plug on the back, run a jumper to the battery and wait for winter.

-Mac
 
Progress report: (couldn't wait for morning)
1. both fuses are good
2. compressor doesn't engage either
3. conclusion, since compressor and blower both use ground signal to activate I will be looking for a bad ground connection.
 
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I see that ground 202 supplies all 3 switches on the HVAC dash control starting with the mode selection switch and jumps to the other 2. From reading some past threads I am expecting the problem to be right there at the mode selection switch terminal and if it is melted I'll be looking to replace the unit. From what I can deduce by looking at the diagram, that ground from 202 in the left kick panel and running first to the mode switch is the only thing in common with both the blower and the compressor.

I see the Mopar control unit is NLA so looking for recommendations on a decent replacement. Crown, Omix, Amazon?
 
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In the scenario posted above; replacing the climate control panel may be required, but the more important item would be replacing the melted wiring harness and connector.
Since purchasing my '01 TJ I have created a spare parts cabinet since OEM parts are getting more difficult to locate.
I have used several sources to locate parts such as EBay, Forum Parts for Sale, Geek Parts, Amazon, online Dealership sales are to name a few.
There are members on the forum in the Jeep Wrangler TJ Classifieds that are parting out TJs.
 
So it's exactly what I expected, the common ground wire where it attaches to the mode selection switch is melted. Looking at all the replacement units that are available I don't see any that come with a new electrical harness on the Jeep side, does anyone know where to get one?

edit: looked at some older threads and it looks like NLA, individual spade terminals might be the only way to go.

melted1.jpg
melted2.jpg
 
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So it's fixed for now... but I don't have a lot of faith in the design. Only the one terminal was damaged on mine so I sliced that part of the plug off and put a spade terminal on the black wire with some shrink wrap. They don't make .187 spades for #12 wire so I had to open up a #14 with a pick. The #14 spade terminal is not strong and I forsee the heat/cool cycles eventually opening up the this metal on the spade where it is crimped. The problem is all the current passes thru the tiny connector terminals on the mode switch, then it goes on to the blower switch which is much more robust and has large terminals.

After replacing my control unit I saw that it was not the original, so this has happened before and will likely happen again.

See my next post for a solution

switch terminal.jpg
 
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Yup. You beat me to relay...I'd tap #86 your switched ignition right off the cigarette lighter/power port since it's right there.

-Mac
 
macleanflood said:
Yup. You beat me to relay...I'd tap #86 your switched ignition right off the cigarette lighter/power port since it's right there.

-Mac
Click to expand...

Great idea, I was thinking about where to tap but it's 106F out there right now so I wasn't going to explore the possibilities till the morning.
 
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I have a '99 Sahara where the AC blower only works on MAX. Based on this other threads, I replaced the blower resistor pack as the likely culprit but no luck. The problem persists.

Would my next step be replacing the Climate Control Unit with the part below, or is there something else I should troubleshoot first?
https://www.ebay.com/itm/2747830156...pid=5337789113&customid=&toolid=10001&mkevt=1

I'm a newb. This will be my first time opening up the dashboard for the climate control and the instrument cluster (I need to replace a couple bulbs). Can someone point me towards a thread showing how to open it up? I suspect I start pulling the fascia and it releases, but I don't want to break tabs off if there is a right way and a wrong way to get it free.
 
You can throw a control unit at it if you want, but you really should troubleshoot what you have first. If the blower works on high then we already know the blower relay is working and sending power to the blower motor. That power does not go thru the switch, it goes directly from the relay to the motor and the modes and fan speeds are controlled by the negative side of the circuit.

So if you look up the wiring diagram in the service manual for your 1999 over in the TJ Resources section you will see that the speed switch has 4 terminals, 3 of them send the negative thru the resistor block but the high speed terminal bypasses all of that and sends the negative directly to the blower motor.

So you either have a dash switch that is not sending that negative to the various resistor taps (which seems unlikely that all 3 positions would fail given the design), or the black/tan wire from the end of the resistor block to the blower is open, likely at splice 208.

Taking the dash apart is easy and also explained in the manual. A plastic trim tool/pry bar can help remove the console trim without damaging it once you remove the screws.

The diagram below is for my 2000 but I believe your 1999 is identical.

blower circuit 2000.jpg
 
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And I agree it might be a good idea to ask @Chris to start a new thread where you came in to avoid confusion and to prevent your post from getting lost in this thread, it can get confusing with 2 different things going on and many participants won't read every post in a thread.
 
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B1Toad said:
And I agree it might be a good idea to ask @Chris to start a new thread where you came in to avoid confusion and to prevent your post from getting lost in this thread, it can get confusing with 2 different things going on and many participants won't read every post in a thread.
Click to expand...

Yes, I agree. Let me know at which post you want me to split the thread and I will.
 
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