Bad Relay in CCRM

Discussion in '1994 - 1995 Specific Tech' started by Hansolos, Jul 29, 2006.

  1. Has anyone replaced a relay inside the CCRM? I got a 94 GT Conv, the AC won’t work and it looks like it's the HVAC relay. They're just solider on there, and I don’t want to drop a few hundred dollars for a $5 relay.
  2. I don't think its possible to simply replace a single relay in those things, but perhapse its possible to wire in a relay in parallel to piggyback the old one :shrug:
    Are they 4-prong or 5-prong?
  3. I agree with 1TMF all the way - the WOT relay is one of the less critical relays out there, so running a stand-alone relay is an idea.

    Joe (Synned) had a HUGE thread about the WOT some time back, as I recall (in case you want to check it out - you sound pretty determined already that the WOT is at fault though).

    This is what the CCRM looks like inside, in case you're one of them techie types that likes to open things up and solder away.

    Good luck.
  4. Paul, for real? It's a hyperlink and the pic appears in the hyperlinked post (for me).
  5. ah, i see it. thanks--missed the hyperlink.
  6. Bad relay

    On that image it would be the lowest cut open relay. It's just a Bosch 4 post relay, I don't know why it couldn't be unsolidered and replaced. I've been looking for that thread that talked about it, but I don't think I've found the specific one.
  7. Yeah you can replace the relay if you so choose. The board isn't sealed or anything. But honestly, why knows why the 1st relay busted, and what will happen to any of the others. So I would just run an external relay and be done with it. If another fails, you wire another external, etc.
  8. After messing with it a little while I found that all the relays would switch after appling 12v except for what would be the top relay from that image. It shorts, so I unsolidered it and tested that relay and it works fine. It looks like there is a short on the board somewhere. All of the relays tested good, I just had to remove that top relay to test it. Now I have to try and figure out why it's shorting. Does any one now exactly what that top relay is switching? It looks like it is being feed by the relay next to it.
  9. Looking at the wiring diagram, there is a diode that separates the AC clutch signal from what could be a ground terminal. If this diode takes a dump, it creates a circuit loop which bypasses the AC clutch output signal, from what I can tell. This could be the problem. There is one connection that joins to the next 3 relays, it looks like a +12V for the coil side of the relays but I'm not sure.

    Here is the diagram I am looking at (its the bottom relay):


    Might be able to swap that diode (10 cent part at radio shack?) and see if it solves anything.

    Attached Files:

    • CCRM.jpg
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  10. 1TallMF, thanks for the diagram! As I tested the rest of the board the (diodes, resisters ...), the diodes seemed suspicous.
  11. No problem!
    Let us know how it turns out