Electric fans on LML ecm.

[Jakezed22]

For starters this is a swap and yes the electric fans keep it cool.

I've been studying lml wiring diagrams and am trying to wrap my head around being able to control my factory electric fans from the lml ecm.

From what I can tell the lml ecm controls the fans digitally?

All I need for my car is a 12v on/off to control the fan relay.

Anyone got any ideas to control the relay with the lml ecm?

 

[MAXX IT OUT]

Are you wanting the fans to run all the time when the igntion is on or just when your up to temp?

 

[Jakezed22]

Are you wanting the fans to run all the time when the igntion is on or just when your up to temp?

Want the ecm to be able to turn them on/off with temp.

I see the lml has an electric clutch?, I was hoping to adapt that to run my fan relay.

I'm not sure how the factory lml electric clutch is setup, I see the ecm wants a fan speed signal and also a PWM output?

 

[MAXX IT OUT]

Want the ecm to be able to turn them on/off with temp.

I see the lml has an electric clutch?, I was hoping to adapt that to run my fan relay.

I'm not sure how the factory lml electric clutch is setup, I see the ecm wants a fan speed signal and also a PWM output?

Far as I am aware, its uses PDM signal to engage the clutch. If EFI live has the ability to change the fan settings you should beable to make it trigger a relay or if you have the right fans to actually speed them up or slow them down. Its has been done on the GM Gas ECU, I just don't have a LML tune to see if they have mapped the LML ECU that far.

 

[Jakezed22]

I'll take a look after work. I went through alot of the lml in efi live and don't remember seeing anything for the fans, but I easily could've missed that.

As far as having variable fans, it would be cool but I've got a set of good stock fans so would like to make them work if possible.

 

[gmduramax]

With my experience with electric fans you’ll want the fans to run all the time to pull air through the intercooler, not sure if yours have a high and low setting. But I wouldn’t have them off ever.

 

[Jakezed22]

With my experience with electric fans you’ll want the fans to run all the time to pull air through the intercooler, not sure if yours have a high and low setting. But I wouldn’t have them off ever.

You've got me thinking now, I kinda think the camaro does have a hi and low fan, fan 1 vs fan 1 plus fan 2. That would probably be a good idea to keep low running all the time. Never thought of the intercooler. Thank you.

 

[THEFERMANATOR]

With my experience with electric fans you’ll want the fans to run all the time to pull air through the intercooler, not sure if yours have a high and low setting. But I wouldn’t have them off ever.

Having them run all the time would defeat the purpose of going with electrics over an engine driven imo. You're probably going to be better off going with an aftermarket PWM fan controller, setting it up to work on engine temp, but also add a switch to the intake to turn the fans on if intake air temps get to high so the intercooler can bring them back down.

 

[Jakezed22]

Having them run all the time would defeat the purpose of going with electrics over an engine driven imo. You're probably going to be better off going with an aftermarket PWM fan controller, setting it up to work on engine temp, but also add a switch to the intake to turn the fans on if intake air temps get to high so the intercooler can bring them back down.

Good point, having a switch on the intake would be the best route for intake Temps.

I might have some time this weekend to set the engine harness up on the bench and do some testing. I'll report back if I find anything interesting.

 

[2004LB7]

For just an on off circuit from the ecm, you could run the PWM wire to a capacitor and then have it trigger a mosfet to a relay. Resistors would be used to bleed of the voltage to calibrate when the mosfet kicks in. Shouldn't be too hard to figure out. Not sure what signal the ecm wants to see for fan speed or if it would throw any codes

I would imagine that running unloaded cruising down the highway the air running over the intercooler and radiator would be enough to keep it cool. Then have it set to kick on when the ecm wants it to as the temps rise.

I ran around for a little over a year in my lb7 without any fan at all. Only got hot when moving too slow for too long or during the hottest days of summer at 100+ degrees. Granted I didn't haul much but some lighter loads

Edit: a solid state relay with a capacitor across the trigger terminals and a diode to keep the current from back feeding back into the ecm would probably be the easiest way to get an on/off trigger from that PWM wire. A resistor in parallel with the capacitor will change when it will turn on

 

[Jakezed22]

With the lb7 in my car the fans never even kicked on once. But I never had it in stop and go traffic. Was always highway cruising and running around town a little bit.

I've got the harness off the car now, so I think I'll set it up on the bench and see what it will do.

 

[JoshH]

Can you use a C6 Corvette fan speed control module as an interface between the LML ECM and Camaro fans?

 

[Jakezed22]

Can you use a C6 Corvette fan speed control module as an interface between the LML ECM and Camaro fans?

I'm not sure I've never looked at a c6 fan speed control. I'll check it out. Thanks.