NC fan control

[tbaggins]

Is it possible to switch the polarity on an output pin, so I do not need to use an addition relay to control my fan? My mustang uses a NC relay for the fan (if the computer kaputs, the CCRM switches the fan on without a ground from the ECM). I would like to use the fan control for the idle up setting (rpm drops a lot when fan switches on), but switch the polarity to control the NC relay. I did a search, and the last relevant question in the general form I saw was from 2015. Curious if anything has changed?

[billr]

I don't think so. They are all "hard-wired" to be what they are (most being switch-to-ground).

[tbaggins]

It is still a switch to ground relay control, the fan is off when grounded and on when not grounded.

Programmable on/off output in advanced settings allows you to set the power on status and active value, so I know it is possible to do what I am asking, just not with the fan control dialog right now as far as I can tell. I was wondering if there is a value in an .ini file somewhere that I can just switch how the pin works.

[ashford]

i have done the same thing. easiest way around this is to use an iac "b" output as it is inverted from the "a"

[tbaggins]

I was reading that yesterday when setting this up, I was unclear how to use the IAC 1A/B for the fan control, so I used VVT instead.
What do you do with opposite line with that setup? Say I use the B line, does 1A need something connected to it?

Great solution, thanks, it was exactly what I need (hopefully).

[nathaninwa]

No it does not, those outputs just switch from ground to 12v+. Just opposite of each other

[tbaggins]

The IAC1B works the same way that VVT does, it switches to ground when you activate the fan. I need to set it up so that the switch to ground turns off to activate the fan. I bought a SPDT relay just in case, but maybe I will just wire something up in the proto area for this. I'm running out easy to access places to put relays.

[ashford]

then try iac1a, memory is fuzzy for me but i think on is 12v for iac. the 2 a and b outputs are inverted from eachother. it is an h bridge driver essenstially a flip/flop circuit

[rukavina]

I think what he needs is help configuring a spare output that is switching ground that is active below value x (temp value) and is open (off) above said threshold. On phone and not 100% sure about spare port pin usage......

[tbaggins]

IAC 1A worked perfectly, thanks! But, it would be nice to be able to invert pins...