IRCM Shot, Can I just wire in a new relay?

[tmielnichuk]

Hi Everyone,

I have been having problems with my 89 MTX SHO overheating recently. I have replaced BOTH temp sensors and thermostat. I tested the IRCM as per instructions I found here on the forum, and I am led to believe it is the problem. here is what I found:

Direct connect the fan to battery... AOK

I get power at pins 1 and 2 on the IRCM

I grounded pin 14 but the relay DID NOT energize and activate the fan.

I am assuming that since the grounding of pin 14 failed to activate the fan then the relay inside is "dead".

My question is this...

Can I simply wire in a new relay (cheap) or do I have to replace the entire IRCM (expensive)

I am fairly handy with a soldering iron and feel comfortable around electrical stuff, but have no idea what kind of relay to purchase and how to wire it up correctly (read safely)!

Can anyone tell me exactly what kind of relay to buy, and exactly how to wire it up? I hope that I am not asking too much but I really can't afford to replace the whole damn IRCM.

Thanks guys!

[email protected]

 

[Off Road SHO]

Tyler,

I did just that, wired in a separate relay ( 30 amp Seimens). And keep in mind that the computer (PCM) activates the relay in the stock relay box by sending it a Ground, not 12 volts. So, you should wire it up with not only the heavy feed wire for the fan supply but also the feed for the relay. You would then connect the other side of the relay to the wire that comes from the PCM that will be sending the ground.

Did I do a good job of confusing you? HTH

Tom

 

[projectSHO89]

You can use a 275-226 from RadioShack for about $7.00

It is not necessary to remove any of the wires from the existing module, the replacement can be piggy-backed onto the wiring harness using splice connector 64-3052, also from the Shack. You will need to make your own plug for the relay unless you can locate a stock connector with a harness.

I'll run by AutoZone tomorrow and see what they have on the shelf.

Steve