Engine won't start w/ DC contoller hooked up
 

I installed my Mark VIII fan and DC controls controller today and my truck wouldn't start. I removed the ground on the controller and the truck starts fine but now the check engine light is on. Does anyone know what I shoud do to fix this?

See if you can read the code at Autozone/Advanced Auto, and post it here.

I have an Innova scanner and it is showing "ERR". I don't want to drive it until I switch back to the mechanical fan or fix this problem. I have the AC wire hooked up to the Grey w/ white stripe wire and the ignition on wire hooked to the battery, which it says you can do if you want the fan to run after you shut off the engine.

something of this nature is impossible to diagnose over the internet

can you at least post pics and more info?

Wait, you have the ignition wire from the controller (yellow one I think) hooked up to the battery?

Yes, the yellow wire is hooked up to the battery. It says you can do this if you want the fan to run after shutting off the truck. I only did it this way for now to test the system. I called the number for DC controls and the phone just kept ringing. Red output and ground are going to the pos. and neg. of the fan, pos. side of battery is going to red input on controller and yellow wire. The blue AC wire is hooked up to the Grey W/ White stripe wire and when I hook up the black ground to the neg. side of the battery the truck won't start, runs bad, or shuts of after a second. After unhooking the ground, it will start but the check engine light is on. I am going to put the mechanical fan back on today if I can't figure it out and quit before I ruin something.

Disconnected the battery and reomved the efan and controller yesterday. With the mechanical fan back in everything is fine and the check engine light has not come back on.

weird, it sounds like you've got it all correct. maybe take some pics and post them up?

where was your grey/white ac wire located? i still have to hook that up.

Brian emailed me back and I'm going to test the efan without it hooked up the truck. He said to put the thermister in hot water and just install the pos. and neg. of the controller to the battery, yellow and blue wires are not necessary.

Tested it with Brian's instructions and it works so I put it in my truck. It's about 30*F here now so I guess it wasn't hot enough to come on. The water temp. guage stayed in the middle for 30 min. before I got bored.

z2896: Please answer this question for us?

if you look down at the compressor there will be a loom of wires going straight up from it and thats it

op it sounds like you have a ground problem, the ground from the controll goes to the chassis not the fan, also chassis ground the fan