Greg Corcoran
SHO Member
This is a bit long - so I apologize in advance -
I have electronic gremlins in a stock '95 MTX with 81K (Bought it with 76K last year). Low speed fan didn't work when I bought it. The dreaded prior owner had diagnosed as a bad CCRM because jumping pins 3 to 1 had the fan run. He procured but didn't install a J code replacement, that came with the car.
When I went to install it I found a D code unit was installed (and checking SHOforum confirmed D code is correct for 95 MTX) , so J was not any use... Tried local NAPA which couldn't get a D code one after 3 attempts that either wouldn't let the car start (no fuel pump action) or wouldn't run the fan or the AC.
I used a locator service through an acquaintance to find an NOS obsolete D code and everything was great for about 2 weeks, then the low speed fan crapped out again. Found the low speed fan winding was really low resistance, like almost a dead short. So I replaced the fan motor with a new stock fan (not easy to find). Since then I've bought a "new, open box" D code off eBay and also had my local old school TV repair shop solder in a new relay in my original one, still got no fan action from either one.
So I don't blow up the engine I hooked up an external 50A relay from NAPA to run the low speed fan after NAPA couldn't find one last summer. Worked OK, should have left well enough alone...
But I wanted a proper CCRM so put in the NOS one and removed the relay. Once the CCRM crapped out I went back to running the A/C to have the high speed fan cool the engine like the prior owner did.
Since neither my newly purchased "open box" or locally repaired CCRM don't work, I put the external relay back on this weekend.
And now something odd - the low speed fan runs whenever the engine is on, or during KOEO test. I put the wires for pins 1 & 3 across the 50A business end and used 3 and 14 to trigger the relay. I also noticed i now have no A/C OR high speed fan when set to A/C on the dash.
What have I got?
Bad luck with CCRMs?
X2J brain losing it's mind?
The signal to run the low speed fan is not to ground pin 14? I understood the EEC grounded pin 14 to call for cooling...
I have electronic gremlins in a stock '95 MTX with 81K (Bought it with 76K last year). Low speed fan didn't work when I bought it. The dreaded prior owner had diagnosed as a bad CCRM because jumping pins 3 to 1 had the fan run. He procured but didn't install a J code replacement, that came with the car.
When I went to install it I found a D code unit was installed (and checking SHOforum confirmed D code is correct for 95 MTX) , so J was not any use... Tried local NAPA which couldn't get a D code one after 3 attempts that either wouldn't let the car start (no fuel pump action) or wouldn't run the fan or the AC.
I used a locator service through an acquaintance to find an NOS obsolete D code and everything was great for about 2 weeks, then the low speed fan crapped out again. Found the low speed fan winding was really low resistance, like almost a dead short. So I replaced the fan motor with a new stock fan (not easy to find). Since then I've bought a "new, open box" D code off eBay and also had my local old school TV repair shop solder in a new relay in my original one, still got no fan action from either one.
So I don't blow up the engine I hooked up an external 50A relay from NAPA to run the low speed fan after NAPA couldn't find one last summer. Worked OK, should have left well enough alone...
But I wanted a proper CCRM so put in the NOS one and removed the relay. Once the CCRM crapped out I went back to running the A/C to have the high speed fan cool the engine like the prior owner did.
Since neither my newly purchased "open box" or locally repaired CCRM don't work, I put the external relay back on this weekend.
And now something odd - the low speed fan runs whenever the engine is on, or during KOEO test. I put the wires for pins 1 & 3 across the 50A business end and used 3 and 14 to trigger the relay. I also noticed i now have no A/C OR high speed fan when set to A/C on the dash.
What have I got?
Bad luck with CCRMs?
X2J brain losing it's mind?
The signal to run the low speed fan is not to ground pin 14? I understood the EEC grounded pin 14 to call for cooling...
