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Hey guys!
The last 3 weeks I've been trying to get my ac working again after a year to no prevail. Thought it was the compressor, replaced that, wasn't it. Thought it was the pressure switch, replaced that, wasn't it. Maybe a leak? Nope, no leaks anywhere. Pressure is good, had it vacuumed and recharged TWICE, should be good to go!.......nope. And fuse/relay is good.
Finally I tested the power going to the compressor, and NO POWER. This had me stumped because the fuse is good (even tried other fuses).
Traced the wiring back to the IPDM behind the battery and it goes into a big plug with a bunch of other wires. I then unplugged it and tested the pin that the wire makes contact with. Holy shat, no power! The other pins read power going to them, but the compressor pin has NONE.
Within the last hour I took out the IPDM and brought it inside and took it apart thinking there's a bad solder but all the solders seem to be making contact everywhere.
Power to the A/C compressor clutch comes through a relay built into the IPDM. Unfortunately the Service Manual only shows the relay arrangement on the front of the IPDM, not on the inside. However, using the Service Manual you should be able to trace from the pin that connects to the compressor back to the relay. Chances are the relay is bad.
For the older Zs, it may. But after extensive research, diagrams, and tearing panels of to get to fuse boxes, I've concluded this:
For the 07-08 Zs there is no relay for the compressor. The only a/c- related relay is for the blower motor located in the kick panel fuse box next to the pedals. There is a FUSE in the IPDM for a/c, but the fuse is good. And the wire that comes from the compressor (running with wiring harness) leads straight to the IPDM into a plug merged with wires from different sources. In the diagram I'm providing, E8 is the plug and within that, 33 is where the compressor wire runs into. Each wire within the plug makes contact with a separate pin that is soldered to the IPDM's "board". But for some reason the pin (that is soldered to the IPDM) isn't even getting power. I'm just stumped....
Calvin,
The A/C relay is not on the front of the IPDM, which is what your attachment depicts. It's on the inside. You will have to take the IPDM apart to find it. Attached is a schematic from the 2007 Service Manual showing the relay.
Well here's a better question. Should I replace and resolder the new relay (if I can find one), or should I just get another IPDM used for a good price? To hell with buying a new one! Those things are more expensive than a new compressor!
As far as relays go, I haven't taken an IPDM apart so I don't know what the inside relays look like, but I do have part numbers for the relays on the outside. The smaller relays (ECM, headlamp, etc.) are part number 284B7-CW29E. The cooling fan relays are part number 25230-7996A. If the A/C relay matches one of these you could try replacing it.
Well the only problem with that is the interior relay isn't a simple plug in. It's a flat square black relay the size of your fingernail that is soldered onto the circuit board. I highly doubt they have a replacement relay for that.
I'm thinking best way to go is either find a junk yard 350z and get its IPDM to completely replace mine, or just buy one on ebay. Z1 has an "upgraded" one but it's price is far out of my range.
Lol either way I guess I'm replacing the whole unit!
Hell I'll just take out the unit sometime this week again and look at the circuit board referring to the diagram you provided. By the way thanks a TON for that. I'll come back to this post and post up some pics from The Adventure of the IPDM too in case y'all ever need references.
Adventures of the IPDM time!
So I got off work and immidiately said hell with it, it's getting stupid hot (Georgia weather). I took out the IPDM yet again and as promised, here's the details:
Location:
Easy to take out, just disconnect your negative battery terminal then fiddle with disconnecting the cables going to the IPDM.
THEN TAKE A PICTURE OF ITS LAYOUT WITH RELAYS/FUSES IN BEFORE TAKING THEM OUT!
There are 8 clips around it. Just use a small flathead screwdriver but be careful not to break them! You'll need the flathead throughout this whole thing.
Once you open it, you'll see the back of the circuit board. Be sure not to damage it in any way or get it dirty.
This is what the front looks like now. There are 6 spots for interior relays, but for some reason there are only 5 total relays. Relay 5 doesn't exist. Note that this IPDM has never been tampered with....well until now lol. You'll need to remove the cuffing sleeves (made that up) from the pins that the exterior relays make contact with. Don't worry about mixing them up, they're all the same. Just remember where they go!
Next you'll need to remove this T shaped metal piece. Not sure why it's there but I'd rather not question something this complicated.
After that you can simply pull the 2 white layers away front each other. It's a little tricky but it'll come off.
Then you'll have this!
Also here's the rest of the circuit board. It's just solder connected to the bigger one I'm guessing because the Z didn't have enough room in its little compartment to make one big board.
Next is another 15 total clips to pry open but you don't necessarily have to hit every single one. As you pry open, you'll see some glue they used to.... keep it together? Don't worry about it though.
Now these shiny plates come right out. Don't worry about mixing them up. They all fit in specifically like a puzzle.
Now unfortunately from here you can't remove anything else without breaking all your solders. Every pin goes through this black cover and is directly soldered to the circuit board.
But at least it shows you the relays on the back!
Now I have a question for someone who has caught my attention on their knowledge of the Z cars. @dkmura
if I may, would you know if the relays inside the 08 350Z IPDM are plug in, or if they're soldered? I inspected it before putting it back together and I just couldn't tell. I started to think it may be replaceable (plugged)...
Hey there- sorry to say that my knowledge of Z33 engineering STOPS when it comes to delving into the IPDM. While there may be times when I've traced down problems, it's never resulted in me closely inspecting or modding any of the relays. I wish I could provide a clear answer, but a man's got to know his limits...
Ok that's fine. I just ordered 5 relays since they're all the same inside. Mainly because I'm not sure which one is for the compressor. I'm not good with tracing circuit boards but I can point out a relay lol
Well, for anyone who cares about this thread anymore, I got the 5 relays all brand new! I just need to replace the relay for the ac compressor but I have no clue which of the 5 relays it is, so I'm just replacing all relays.
However, because my compressor bolt got stripped, got loose, and made the belt GTFO, I need a new bracket for it before I can test the compressor. Will update when finished!
Update:
I replaced 4 out of the 5 relays. They are all soldered through the circuit board so I had to go out and get a soldering iron today. Reason i didn't replace the last one was because it was getting late and I just got tired. The hardest part was getting the old relays off! Especially since i couldn't get my hands on some unsoldering copper. Ended up just breaking the old ones off.
Now note i said i didn't replace one of them. Well just my luck, the fackin compressor still doesn't work.......
If you wanna go back on this thread, it's the one relay that is by itself. More than likely that's the culprit. Will update again when I get around to it (probably soon).
Good news and bad news!
Good news: I still have a p3nis.
Bad news: replacing the relays absolutely did not work. In stumped at this point. Does anyone have an idea?
I'm considering just getting a used ipdm and throwing it in there
Update on the issue:
I got an IPDM off of @SilverGLE and swapped mine out today. Guess what??? STILL NO AC
I haven't tested power coming out of the pin, for the wiring coming from the compressor clutch, yet due to the sudden holy thunder storm from hell. So after work tomorrow, I'm gonna see if the compressor clutch pin on this IPDM is getting power. If it does, then I'll have to have the lines vacuumed and recharged. Hoping for the best here!!!!
Update on the issue:
I got an IPDM off of @SilverGLE and swapped mine out today. Guess what??? STILL NO AC
I haven't tested power coming out of the pin, for the wiring coming from the compressor clutch, yet due to the sudden holy thunder storm from hell. So after work tomorrow, I'm gonna see if the compressor clutch pin on this IPDM is getting power. If it does, then I'll have to have the lines vacuumed and recharged. Hoping for the best here!!!!
Holy crap, what a PITA!
Bravo on disassembling your IPDM and checking the relays, too. I hope you can find the root of the problem! It's too damn hot in GA to be without AC this time of year!
Bravo on disassembling your IPDM and checking the relays, too. I hope you can find the root of the problem! It's too damn hot in GA to be without AC this time of year!
You're telling me! Getting off work at 3 kills a 30 minute ride home
05-02-2020, 01:24 PM
A/C problem!
