Passenger side fan failed

[vps3922]

I thought I throw this out to the crowed. I looked around a bit in the forum but could not find a thread. I recently noticed that my fan fail light came on frequently. My friend Dave (sdg3205) tested them when the light came on by checking the airflow and said that both were spinning. I therefore wanted to adjust the settings on Bitsyncmasters fan fail module today and noticed that the passenger side fan did not spin. :ehh:

I therefore think that it is either a flaky contact (maybe ground, if separate) or the unit simply failed gradually. I would therefore like to know if there are any troubleshooting tips? I can recall that I cleaned all contacts when replacing the radiator, but I am not sure if there is a separate ground contact. I do not have a lift and nothing to give me more space in the front to work, but I have a friend with a lift and will be able to use his lift next week.

Any pointers are appreciated. I already checked the little fuse on Bitsyncmasters fan fail module and it is looking fine.

[DMC5180]

What adjustments were you doing on Dave's FF unit. The FF unit is where the electrical feeds separate going to the fans. Remove the FF unit and reinstall the jumpers to see if you still have one or both fans running.

[vps3922]

What adjustments were you doing on Dave's FF unit. The FF unit is where the electrical feeds separate going to the fans. Remove the FF unit and reinstall the jumpers to see if you still have one or both fans running.

I wanted to adjust the sensitivity according to his manual. He said in his recall post that sometimes a higher voltage difference is causing a fan fail light to engage. He therefore made the FF programmable (see his installation manual).

[vps3922]

Hmm, I have a jumper but there are no 20A fuses on each side. It is a simple jumper cable for the fan fail module socket. Is this what DMC installed as a workaround? :what_the:
DMCH offers the jumper with the two 20A fuses.

[Bitsyncmaster]

I would pull the fan fail unit and use a jumper to test each fan. You don't need the engine running, just key on, then AC to norm and that should turn on the fan relay. Maybe someone has a photo of the jumpered fan fail which will show you the pins. Power comes in on the center end pin and each fan is on the side pins.

My fan fail unit lets you modify the fan current compare value from 20%, 30% or off. That change only changes the fan fail light operation. Each fan runs though a current measuring device. The fan fail does not switch fans on or off. It will even run the fans without power to the electronics inside the unit.

I did have one of those current compare ICs fail so one fan would not work. That has been the only fan fail unit to fail so far.

[DMC5180]

Hmm, I have a jumper but there are no 20A fuses on each side. It is a simple jumper cable for the fan fail module socket. Is this what DMC installed as a workaround? :what_the:
DMCH offers the jumper with the two 20A fuses.

The original DMC service bulletin was for jumper wires only. http://www.dmcnews.com/bulletins/ST-06-9.82.html Later on the Aftermarket vendors started installing the Fused jumpers to protect each fan circuit.

[vps3922]

Tested a bit further and used the old jumper cable. Both fans work perfectly. It is a broken FF module.