A common issue with costly implications on 2015 RAM 1500 EcoDiesel trucks is that the A/C does not work and is completely dead, which means I have no heat or cold air. The controls don’t work at all, which may look like a blown fuse at first, but that is not usually the case with these trucks.
From what I’ve read on the RAM truck forums, this issue appears to be a common problem. According to the Dodge / RAM dealership in my area, to fix this, I need to replace a part of the $1400 A/C module (I am in Canada, and our dollar is going the way of the peso). In addition, the dealer diagnostic costs $250 plus labor per hour. Add to that shop supplies and taxes, and you are out the better part of $2500—all over a resistor that costs less than a penny, so keep reading.
After getting the YOUCANIC scanner, I noticed the HVAC system wasn’t showing up in the scan results. After consulting with YOUCANIC technical support, I got a few pointers and started a systematic diagnosis of the system.
From a YOUCANIC UCAN-II-B that was not communicating with the HVAC / air conditioner module, I deduced that a module was offline by noting that only that module was not communicating with other modules or the scanner.
The pinout diagram above is for the climate control module connector in RAM trucks 2013-2018. This connector attaches to the Climate Control module and is located on the passenger side, A-pillar behind the lower glove box door.
- Ground is pin 14
- Power is pin 1
- Switch is pin 2
- Can + is pin 23
- Can – is pin 24
With the negative test lead in the ground, a probe of pins 1 and 2 should show battery power (~12V), while pins 23 and 24 probes should show ~2.4V. You can rule out bad ground if battery power registers at pins 1 and 2. If ~2.4V at pins 23 and 24, you can rule out an issue with the can bus. This leaves the module itself as the cause, which…
