$6E bin my fans turn on before the set temp in the prom. Seems like it's more on a timer than a temp switch. I can't find anything about it in the definition file.

If I turn the key on... and wait, the fans will come on after like 2-3 min. It only started this a few days ago. I wired both relays in parralell so that the computer would contorl both fans. Worked fine for a week.

I've got the FANNO flag checked in the prom also.

ideas?

 

If you have the ecm now turning on both relays, you doubled the amount of current the ecm has to deal with, and that can take out the fan switching in the ecm.

When things get heat sensitive, it can be an indicator that, an output driver is failing.

While ecms have an inherit overkill in the design, a 100% increase in load isn't always tolerated.

Also when relays open and close they generate an A/C spike and that can overload the design.


FWIW, with fans sometimes you can miswire them, so that as they spin, they generate some voltage and turn themselves on.

 

I guess I figured that it didn't take much to click the relay on. I will unplug one of the relays tomorrow and see if that made any different or if I maybe fried part of the ECM.

The fans are wired same as factory, except I just put the coolant temp switch operated fan relay in parallel with the ECM controlled fan. The load power and ground wires are factory to the relay I just looped the relay open/close wires.


Never would have thought of that Grumpy. Good call.

Just thought I was cheating and that it would be too easy. Guess I'll have to go buy that Hypertech switch now.

 

Or, just wire the second relay so that the first relay's output to the fan turns on the second relay.

 

Okay I didn't get a chance to re wire them and had to go on a 70 mile trip. Got there. Hit the 500mile mark on the new engine. Started it to warm up the oil for changing.

Turned it off. Changed it. Went to start it again and it would flare up and immediatly die. Gettin spark gettin fuel pressure. Couldn't even keep it running with the pedal. Just flare and die.

Unplug maf... runs with SES light on fine. Try friend's spare maf. I can get it to somewhat hold a 4000rpm with the pedal but it wont idle and runs ruff. Not even close to drivable.

Is it possible that I fried the ECM or is it just time to go SD and get the Commander?

 

165s fo that........

just remember when a Commander dies, your stranded until you get it repaired, and that may not be as cheap as getting one from a junkyard.