Three relays or two for fan wiring (e40)

[bubba68ss]

Can I run e40 PCM controlled dual fans with just two relays (one relay for one fan, one for second fan) or do I have to wire them up for three relay setup like the original car? I usually do single relays for 0411 projects but someone told me e40 doesn't have option in tune to run them like that. Doesn't make sense to me... Seems they would work as I have always done with other pcms.

[joecar]

3 relays;

they control fans as follows: off, low speed (series), high speed (parallel);

it may be possible to reconfigure this, but requires some thought after looking at the wiring diagram;


post the wiring diagram that you have...

[bubba68ss]

Using two relays would essentially give me two high speed fans where one comes on them the other kicks on, right? Won't the two fan wires from PCM so this?

[bubba68ss]

19035

This is the wiring

[joecar]

Using two relays would essentially give me two high speed fans where one comes on them the other kicks on, right? Won't the two fan wires from PCM so this?Yes, correct, this will give you one fan, and then 2 fans, both at high speed.