Megasquirt fan control

Ms2 3.57

Have pin 31 to ground side of relay for the fans.

Ive tried eeading and doing setting up in the ecu to control the fan, but just can't get it to make any sense.

Can someone spoon feed me? Using tunerstudio.

Boost/Advanced -> Programmable on/off outputs:

Turns on at 83 deg C, turns off at (83-3)=80 deg C.

Awesome!!

Ill look at tunerstudio while hooked up to the duster in the morning. Heres hoping i can make it work.

So i tried it this morning. No operation of the fan. Fan works fine when the ground pin of the relay that is hooked to the ecu is grounded. So that end is good.

I tried the fidle setting, and all 3 p settings. Set them all to straight 0 across the board so i could test.

What am i missing now? It must be something stupid or simple.

Are you sure it's not pin 30?

Youre right. Should have said pin 30.

That will use the FIDLE channel.

Does it toggle off and on in output test mode?

Umm.....

Spoon feed me? Test mode is not something I havr found yet.

Output Test Mode documentation

Oh, yeah, I should have mentioned that you'll have to select the correct pin in that dialog that you have the fan connected to. I have mine connected through a separate circuit that is wired to JS11, since I already had the FIDLE pin in use.

Ok, so i found the issue. The wire from the megasquirt had come disconnected from the relay. Now, during the test function the electric fan can be operated by the megasquirt.

But....

When i shut the key off, the fans turn on and stay on. Why????? Is there a setting im missing? Its almost like rhe megasquirt is defaulting to ground when powered off.

Ideas?

In reply to Dusterbd13:

I dunno about the megasquirt behavior, but if needed, just move the relay coil hot wire to something ignition switched. Then it doesn't matter if the megasquirt grounds the pin on shutdown, you'll still have the desired effect of ignition off = fan off.

was it up to temp and running to cool itself Down?

It shouldn't run if the MS has no power. Moving the high side of the relay coil to something switched should work fine to fix it.

Haven't even started it yet today. So its not temerature related.

If i unplug the harness from the ecu, the fans dont run. So its in the ecu.

I CAN awitch the trigger side from constant to switched. But, id rather know why this is happening and correct it instead of doing that. Seems odd.

Could it be a setting is screwed up? Or hardware issue?

After a bit of searching, turns out that the fidle output DOES default to ground when key off. Crap. Now to find a handy place to pick up switched without tearing half the damn car apart.

I made the same mistake. Yeah, the coil needs to have a switched positive.

I wish I had known when i was wiring from taillights to headlights. I would have ran one while it was easy.