IRCM disassembly and repair?

johnwartjr

Registered User
I'm experienced doing component level PCB repair and rework.

My 95 SC started leaving the radiator fan running after the ignition was turned off last year. Someone here suggested tapping it with a wooden handle of a hammer. That fixed the problem, and it has returned once or twice since then.

This morning, it did it again, and no amount of tapping is stopping it.

So, I unhooked the battery, so the fan won't drain the battery.

The last time this topic was discussed, someone mentioned a stuck relay in the IRCM, which my understanding is inside the black box attached to the core support, in front of the air cleaner box.

So, it looks like getting the IRCM box out isn't that difficult.

Does anyone have any advice as to what I'll find inside the IRCM once I open it? Suggested parts I can use to replace the relay? Gotchas? Advice? Anything else I should do while I have it opened up?

Thanks!
 
I have repaired mine, had a low speed fan problem and had to replace the transistor that controlled the relay. It is a pretty easy board to read. If you get on ALL DATA and get the wiring diagrams for your car it isnt hard to open and repair the unit. If i remember right mine had rivets holding the cover on that I had to drill out.
 
If you are handy with a soldering iron you can replace the relays on the board. I'm currently replacing the 3 relays on a friend of mine. You'll basically see a pcb with 3 big black relays with 4 pins on each soldered to the board(plated through hole). Be sure to remove the protective coating on the pins before attemping to solder and use the proper solder wick with flux. Should be fairly easy for you as you said you know your way around circuit boards.
 
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I like to cheat and use relay's with a wiring harness so they can be replaced easily if they fail.
Alan
 
Thanks, I have a vacuum desoldering station and desoldering the relays should not be difficult.

Can anyone provide a relay P/N and source so I can get them before I remove the IRCM?

Thanks!
 
OK the IRCM is out and open. Sure was easier than I expected.

Anybody know if it's K2, K3, K4 or K5?

I'm guessing it's not K2.
 
I had to follow the wires I highly suggest just doing all 3 while you are there, build a wire harness and run the relays to the core support.
Alan
 
It must be the center of the bigger cube relays, as it was shorted. I desoldered it and smacked it hard with a hammer on all sides and now it's not shorted - but I'm sure that's just a temporary thing.

I'll hit the parts store tomorrow and see what I can find. I see Autozone has a $5.99 Pilot relay that would work if I build a harness. Finding a PCB mount version will be difficult if not impossible, so I may have to go the harness route.
 
Did the remote mount relay with a wiring harness this afternoon. Pretty painless. Thanks for the pointers.

Had to make a small notch in the cover of the IRCM box to route the wires out. How do most people reattach the lid? I used some zip ties.
 
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