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Discussion Starter #1 (Edited)
OK so I'm in Southern California and it the 1st of August, Its hot.

My 04 Quad cab with 152k and the Hemi has great A\C one day the fan blows hard and the next morning it doesn't blow at all. Now when I got the truck at 100K the only weird thing was a wire was jumped from under the glove box on the passenger side to a switched electrical under the driver side. The wire on the Passenger side under the glove box is pretty large and it's blue with a yellow stripe. Way back when the crimp on connector had burned and the fan stopped working, so I put on a new crimp on,right? When the fan stopped this time its the first place a went. I found a burned up crimp on and I decided to fix it right this time. I ran a big fat # 12 from the fuse box to the firewall on the drivers side and to the glove box on the passenger side. Soldiered and shrink rapped the connectors and I put a nice spade clip on the fuse box side and hooked that end to a relay for the rear window defroster. ( I don't have a defrost in the rear window) The fan comes on but now the damnedest thing is happening.

The air blows cold but the light on the AC button doesn't light.

The Speedometer doesn't work

It thinks its 72 degrees outside all of the time. Its Not!

I have a Break light on the dash like iI have left the Parking break on,( its not)

I have an ABS light on

Also, I might be crazy but it doesn't seem to be running right.

So I take the negative battery cable off for about 3 hours. I hook the cable back on nice and tight and on a clean post and start the truck up.

Guess what I got????

The air blows cold but the light on the AC button doesn't light.

The speedometer doesn't work

It thinks its 72 degrees outside all of the time. Its still not!

I have a Break light on the dash like I have left the Parking break on,( its not)

I have an ABS light on

Also, I might be crazy but it doesn't seem to be running right.

I'm scratching my head,

Any Ideas??

Joe
 

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Worst case scenario is that you fried or damaged your ECM.
 

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Discussion Starter #3
Obviously, frying an ECM would be my biggest concern.

If I understand the way the systems works is, if I was to get my hands on a new or refurbished ECM it would need to be flashed or somehow installed with the Dodge Dealer computer interface. ( I forget the name of their tool at the moment)

One update since my last list of messed up items is that I have no ODBII port and things like the alarm to lock the doors doesn't work in addition to the other items I listed originally. Its drive able, but its not like it should be and for the very first time since I have had the truck I am getting a check engine light. I cant check the code because the code reader port doesn't function, but hey.

I have a theory that I'm going to work on today and that is the hardwired hot from the battery to the A\C fan in the dash is not a good option as the CAN BUS cant talk to the other items in the system and I need to get the power to the A\C fan from the A\C fan fuse on the Main fuse box or Power distribution panel or whatever it's called. The closer I can get the system back to its original design the better off I will be assessing the actual items that are working incorrectly.

I come from a technical background (Telecommunications) and basically understand what the CAN BUS is doing and I get the gist of the 3 computers working together and I have the service manuals to help me along. I would be thrilled if someone has any experiance with this portion of the truck and can give me a couple of clues along the way.

Working towards the finishing line,

Anyone gotten a new or replaced an ECU? What can you tell me about the pain involved in that delightful experience......?


Joe
 

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Have you unhooked the new wire you ran? Have you checked grounds? I have fixed a few cars (non dodge) that were having similar issues as yours and two were a bad ground blower/fan and another was bad ground under the dash and another was a bad block to chassis ground.
 

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Discussion Starter #5
Anyone changed out a PCM?

Anyone replaced a PCM before?

I read that you can clear the PCM if you pull the fuse #23 on my 2004 and get in the truck, close the door, buckle up, and then turn the key like you were gonna start the truck. The truck wont start because no fuse in the PCM but it is supposed to chime twice and then again chime. Mine chimes twice and never chimes again. The PCM does not clear, it try's but it wont complete the action.

Doesn't sound good,

Anyone changed out a PCM?

Joe is getting bummed out.......
 
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