SpeedyWeber

I have converted over to an electric fan from a Taurus. It's controlled by a FAL adjustable temp control box with temp probe. I have also converted to a 130amp alternator.

When I had the fan wired up on high speed it would stall the car if I was sitting at idle at night with the headlights on. During the day with the lights off the car would not stall but there would be a noticeable surge at idle when it comes on.

I have a 75 amp relay wired in as well but I'm not even sure if it is necessary with the FAL controller.

I rewired the setup to the low speed wire for less of a "hit" when the fan comes on but of course on low speed when it is hot outside the car takes much longer to cool down and if I'm romping on the car light to light it'll get pretty hot until I cruise at a higher speed.

I also have a 2 core aluminum radiator and 180 t-stat with high flow pump.

I am about to switch over to a larger fan from a lincoln and I am removing all the fan controls and installing a DCC variable speed controller. I also have a smaller diameter alternator pulley that will go on.

So what would cause such a blow to the charging/electrical system that my car would stall? If the fan comes on when driving nothing is noticable, it's only at a stop at idle. Wrong gauge wires? Maybe the relay? I understand there is a surge in milliseconds when the fan comes on and factory equipped electric fan vehicles "bump" the idle up when the fan comes on, especially with AC, but I wouldn't think I would see my car stall from it. My car idles at 900 RPM in neutral and drops to 700 RPM when I depress the clutch. Do I need to bump it a bit higher? I do have a AFM N-41 cam with AFR's, so maybe it's vacuum related?

SpeedyWeber

No one has any ideas?

TwotoneVert

Is everything else electrical working ok? I would check to see if your grounds are clean and making good contact. I dont have an electric fan, but had to add an additional ground from the block to the battery. That could explain the surges you are seeing, and its a 3 dollar fix.

HACKGT350

i have the same fan with the stock alt. never ever had a problem like that. i have mine wired to a switch so i control when it comes on and off but i still never had my car have a problem stalling when i turn high on

SpeedyWeber

I'll try adding another ground to the battery,. That's a good place to start.

2 kwik

bump idle speed 100 rpms

silver91gt

I had this problem a couple years back, when I put my first taurus fan on, the stock alternator wasnt putting out enough amps to keep the fan going fast enough, the motor got hot and so did the TFI module, switched to a 3g alternator, with a different fan, and it fan fine.

SpeedyWeber

So I reconnected my negative battery wire to the motor mount. It was connected to the A/C bracket for some unknown reason. I also connected the variable speed controller to the high speed setting for the fan. So far it seems to be better but the temperature here has dropped to 70's so the real test won't be until it gets warm again and I run the A/C.

r.barn

If you have u/d pullies take those POS off.
Will help TONS

SpeedyWeber

I have lightened pulleys, they areNOT underdriven.