Dual relay fan fail

[John Rogers]

Does this mean that you plan to produce two Fan Fail modules?

One for the two fans operated by one Fan Relay and

a new Dual Relay Fan Fail module which allows each of the two cooling fans to be controlled by their own Fan Relay (i.e. 2 Fan Relays).

[Bitsyncmaster]

Does this mean that you plan to produce two Fan Fail modules?

One for the two fans operated by one Fan Relay and

a new Dual Relay Fan Fail module which allows each of the two cooling fans to be controlled by their own Fan Relay (i.e. 2 Fan Relays).

Yes. One for stock wiring that uses the original one fan relay. The other is for those owners that have modified the wiring to use two fan relays. That was done before the vendors developed lower power fans. But the double relay unit has one advantage, it provides a fan fail light if one or both fan relays or fuses fail. The original wiring if the one fan relay fails then the fan fail does not get power and can't turn on the fan fail light.

[Josh]

To clarify the function of this:

This is to restore the function of the fan fail light when the wiring is modified to have one relay per fan, not a single relay for both fans?

There is some comments about this utilizing 2 speed fans, I dont think this is what this does. On the LS swaps for example, the low speed fan turns on at 210F (or if the AC is on) and the high speed fan turns on at 220F.

I also have had both VW 2 speed fans running off one relay for each speed for many years. Im not sure the benefit of splitting the fan relays up for single speed fans. You do need to run a new length of 10Ga wire to each VW fan if you plan on using the highs though. The existing wiring is only suitable for the lows (14Ga)

[Bitsyncmaster]

To clarify the function of this:

My dual fan fail looks at the fan relay on signal and each of the wires going to the fans. If either fan wire is less than 10.0 volts when the relay on signal is active, it give you a flashing fan fail. There are some time delays on the fan fail light built into my unit so it can work with delayed relays (to stagger the fans on and off) and not give you a fan fail light.

No fan currents pass though this unit. It just looks at voltages. So wiring you make to this unit can be 16 AWG or smaller. I use 16 AWG because it crimps nicely to relay pins.