Macanic

Looking to see if there are any real mechanics on here that can help a frustrated mechanic resolve an AC issue. Question is does the ECM or BCM set the ground for the AC relay in the PDM to engage so the compressor to engage. No smart remarks please, just asking for a lead other than to take it to the dealership. Compressor works fine doing the static car test, Keyon, mash interior light button 10 times. Can jump wire from PDM to compressor and it engages and cools fine, ac control module replaced, new ribbon wire, all new sensors, ac control replaced, Any advice would be appreciated. I really think it is a ground issue with the relay, all this happened after a simple OEM radio swap, slid one out another OEM back in. No AC after that.

bre240z

You sure that climate control flat wire is plugged all the way in? Its gotta be something in that area where you pulled the radio out. Just get in there again and double, triple check. Not being a smart *** here but maybe plug in the old radio and see if the Ac works. Good luck

Macanic

Second one in place now, just changed it to say I did. The AC relay is not serviceable in these cars(Thanks Nissan), even swapped out IPDM just to rule out. Relay fuse in IPDM is hot, it is just like the relay is not going to ground to energize the compressor wire. I guess my question would be, what initiates the grounding of the relay, ECM or BCM.

Tomek350Z

iTrader: (14)

Looks like he ECM grounds the control side of the coil

Tomek350Z

iTrader: (14)

Tomek350Z

iTrader: (14)

keep in mind this is service info for a 07

Macanic

Thanks for that, wading through the wiring diagram is like wading through a mine filed. Got ECM uncovered now, try to trace ground wire.

bre240z

I dont know how to share another thread on here so i just copied the link. See post #31

https://my350z.com/forum/maintenance...problem-2.html

Tomek350Z

iTrader: (14)

no problem, actually looking at the wiring diagram, it looks like IPDM is actually responsible for grounding the relay coil. The PCM just sends the message over CAN Bus. Do you have any other DTC's? I would recheck the wires near the radio to see if you bumped up against something or pinched a wire against a bracket. Double check the E108/M15 inline connector to make sure the CAN bus message is making it to and from the ECM

Macanic

Can you identify the brown plug on the harness. Radio, ac control harness.

icer5160

iTrader: (4)

Hello Macanic,
I believe the brown plug is for the radio steering wheel controls. The base model 350Zs did not have steering wheel audio/cruise control switches, but the dash harness still includes the wiring at both the radio and steering wheel. I know because I've done a plug and play upgrade to include steering wheel audio controls on my base 350Z (without ever touching the OEM non-bose head unit). The large white plug next to the brown plug is also for the radio (again if memory serves). The remaining small white plugs should be for the AC control unit that mounts below the radio.
Cheers!
-Icer

bre240z

any updates?

Macanic

Not yet, trying to decide whether to take it to dealer and let them scan it or keep plugging away at it.

icer5160

iTrader: (4)

It could just be the resolution of the pic or reflection/glare, but the pin on the yellow wire on one of the smaller white plugs appears to be smashed or slightly pulled out of the harness plug. The pin looks to be exposed. See photo I edited.
-Icer

bre240z

it does look like its not all the way in

Macanic

I found the problem with the help of a great mechanic a Nissan Of Mobile, 3 broke wires of my own making in the big harness under the battery. Word of caution, if you drill through through the fender wall, right side, under the battery, do it very carefully. I have AC. Thanks Shane.

bre240z

good to hear. Just curious why were you driling in that area?

AngelaDuff

Ok, glad to hear you found your solution.