Ok, perhaps my wiring got crossed somewhere.

This has been working fine for 6 or so months. I had FAN-1 turn on at ~195 F and FAN-2 turn on ~205 F.

Does anyone know why the FAN-1 on a '7730 would suddenly get 12+ (positive) volts instead of a ground signal?

I tried pulling the ROM out to got o LIMP home, and FAN-2 comes on with a negative, but FAN-1 gets 12+ ?!?!?

I will re-check my pins tonight. I was wondering why it got so hot (210) so quickly.

Thanks!

 

I know the vettes have the fan's reversed, their fans require 12V out of the ecm to turn on. To run an ARAP (corvette) bin on an f-body you have to check the FANNO flag, otherwise the fans are on constantly until you need them the most.

I'm not familar with the the 730 at all, but I'd assume their's a similar flag. Looks like maybe the N/O flag on the N/O fan request page in 8D_v03.ecu, make sure thats checked...

EDIT: Looks like it shouldn't be checked

 

huh?

I guess, I better double check my bin. But, why would it be this way in LIMP-HOME? E.G. the chip was removed?

 

Hmm, wiring??? Anyone?

Or bad ECM?

 

What? The fan is connected to a relay, when the relay is grounded the fan kicks on.. no?

-- Joe

 

This was from over a year ago. I found the problem was a bad relay. I am not sure how I found a positive 12 volts. Unless the computer puts it out to keep the fans off. I haven't checked.

I actually get a ground to turn on Fan-1 or Fan-2 on my '7730.