Hi all first post here, I have a 1500 ram van, the ac stopped working on it, the mechanic said its the Air conditioner module? and a new one would cost 700.00??? First off, where is this AC module located? he said he bypassed the module and it works fine, but it has to go threw the module. any Ideas?

 

JAY87T,

The first question is, what year and engine does the B1500 have? The B1500 is a second generation of the Dodge Ram van and there are two types of HVAC systems used. One was 1971-1997 and the other type 1998-2003.

First, I would find out what the codes are for the vehicle dealing with the AC system.

In some cases the cycling-clutch-switch for the compressor could be the problem. On the older type there is a damper pressure cycling switch. In any case, the part is easy for a person with home garage tools to replace and cost less than $50. But I have no idea if that is the case for your van. It's only a guess.

As for the $700 for the entire AC module, that's silly. Even an AC compressor doesn't cost more than $400 max. The AC module is located on the passenger side of the van when you open the front hood. It's that BiG black HVAC box.

I can't see why it needs to be replaced other than if a squirrel got in there and died. That indeed would be an issues to change out the entire unit. If the Evap core is leaking, then taking the HVAC box apart and replacing the core isn't a hard job, but a lengthly one at best. I would find a good garage to do that job.

Take the van to another garage for a second opinion. Don't tell them anything about the other garage and just state that the AC isn't working. See what they come up with.

I've looked through my Hayes Repair Manual for the Dodge Ram Van, book number 30065. It says that if the AC system isn't working and that this system is control by vacuum lines from the dash panel in the vehicle, check the fuses first.

Hope this helps some. Maybe Chump or the others can chime in here too.

 

Hi Stev, thanks for the reply, its a 1500 with the V6. Its hard to remember what he said again on the phone, but he said if he grounds the relay the ac will kick on, but the ECM or something module was no good and I needed a new one and plus it would have to be programed??? is he talking about the the Main ECM on the van? that controls the AC? im sure something tells the Idel to jump up abit when the AC is on. in all cases, if it goes on when you jump the relay, cant one just hook up a switch and turn it on like that?


Just a update, I did jumper the relay and the AC turns on and is cold, I tried a differant relay, makes no differance.
I think the ECU is not giving a ground to the relay to kick it on, thats what he was talking about, and he said a ECU costs 700.00 and he cant find a used one....

 

Where is the thing you jumpered? I'm thinking the mechanic and you are talking about the low-pressure cut-off switch. This is on the passenger side just next to the Accumulator/Drier and evaporator on the low-pressure side, on a 1999 model what year did you say again? I think it sits on top of the Accumulator/Drier on later models.

If that switch is out, the replacement would depend on the year model. The later models require only the switch, but in my case I would need the entire line to which it is attached.

You say when it's jumpered it works, but does it cool well? It may be low on refrigerant and the switch is working properly.

Cheers,
Lee

 

I jumpered the a/c Relay in the fuse box under the hood I guess a signal comes fromt he Main ECU and tells the AC to kick on, He said the ECU is not putting out a ground signal to the Relay, I checked both pressure switches with my ohm meter, they apper to be fine. Im thinking I will just wire a switch to bypass the ECU signal and turn it on manualy.

 

JAY87T,

Replacing the ECM is very costly and isn't always the solution since it's the main computer brains of the vehicle. Even a used one would have problems since these ECMs/PCMs over time go bad. To re-program the ecm/pcm, it must be cleared of error codes, match your engine type, exhaust type, a/c controls (rear too if required), automatic vs. manual tranny, and sized properly for the tires since both 17 inch and 15 inch are offered. It's harder to match an ECM/PCM for a B2500 since so many options exist.

Here in this fourm of Ram Vans is a link for ECMs/PCMs rebuilds. The cost is lower, but you need to send in your old ecm/pcm as a core charge. https://dodgeforum.com/m_417287/tm.htm If you have to replace it, call them to verify a good match to your vehicle's configuration.

The vehicle idle is controlled by the IAC on the newer Ram Vans. You mentioned that you have a 2001 in the subject heading of this thread. The IAC could be a cause why the AC isn't running right under load. My Hayes Repair Manual mentiones a surging and rough idle when the IAC gets too dirty or needs to be replaced. See my thread here on that. https://dodgeforum.com/m_525409/tm.htm

Smartobject, Lee, has some good input here too.

Hey, if your ECM/PCM is having a bad ground, trace you battery and other ground wires for corrosion too. You may have start doing that too already, even with the switch.

 

Hey all,
Have '01 1500 with 5.9 with AC problem. System shows correct charge and will operate upon cold start, but kicks out while driving. Also, will not engage after turning switch off and back on. Jumping switch also does not work even though it shows propper volts. Although, I can get clutch to operate by tapping it with a piece of wood. Not sure if its vaccum or clutch or lack of patience. Any ideas are welcome. Thanx

 

You may want to start a new thread as this one is six years old and does not really correspond to your issue.

Sounds like the a/c clutch is failing. In theory you can replace it but given the special puller required it'll be simpler to replace the compressor.