12V to one cooling fan.

[rustycarr]

Fan relay would not kill one fan. If you tested the voltage at the fan connector and get no voltage when the other fan is running then you need to test that you get voltage (with the one fan running) at the fan fail jumpers. All three jumper should have the same voltage.

Correct, I get no voltage at fan connector on driver fan when passenger fan is running. Ill check the voltage at the fan fail jumpers.

[rustycarr]

Maybe check the non-functional fan's ground?

I cleaned the grounds.

[David T]

I cleaned the grounds.

If you don't see +12 volts at the plug to one fan you need to check at the relay block where the Fan Fail Bypass is to make sure you are feeding power into both wires going to both fans. A connector could have backed out, a wire could be burnt, a fuse could be blown (even if it looks good so check it with a meter). If you can confirm you are feeding power into both wires then you have a problem somewhere between there and the plug for the fan that doesn't have power. I have see the Fan Fail Bypass wire burn so examine it thoroughly.

[rustycarr]

If you don't see +12 volts at the plug to one fan you need to check at the relay block where the Fan Fail Bypass is to make sure you are feeding power into both wires going to both fans. A connector could have backed out, a wire could be burnt, a fuse could be blown (even if it looks good so check it with a meter). If you can confirm you are feeding power into both wires then you have a problem somewhere between there and the plug for the fan that doesn't have power. I have see the Fan Fail Bypass wire burn so examine it thoroughly.

will do, ill report back. thanks.

[rustycarr]

Fixed it, one of the connectors had indeed back out and wasn't making connection. both fans working again. Thanks for the help!

[rustycarr]

Well, 1st drive, the driver side fan blew its fuse, all connections are solid, grounds clean.The fan spins freely, doesn't feel wore out, im wondering if in its old age, is drawing too much current for the fuse to handle? ive seen this issue on this forum before. any other thoughts?

[Rich]

Yes, that fan may be drawing too much current.

Another cause of a blown fuse is a short circuit.

Check at least the visible 12V wire you can see near or to the rear of that motor. You may see more of the wire if you pull the panel below the spare wheel. Suspicious spots include wire retention clips on the frame or on any grounded brackets. Check the wire insulation at any clip along the way. Also inspect any previous owner hacks.

And look closely at the duplex power-ground connector on the fan motor pigtail, verifying it is clean, no schmutz or crap creating a short between the twin connectors in there. You say the connections are solid but are they clean, too?

Well, 1st drive, the driver side fan blew its fuse, all connections are solid, grounds clean.The fan spins freely, doesn't feel wore out, im wondering if in its old age, is drawing too much current for the fuse to handle? ive seen this issue on this forum before. any other thoughts?

[Bitsyncmaster]

Well, 1st drive, the driver side fan blew its fuse, all connections are solid, grounds clean.The fan spins freely, doesn't feel wore out, im wondering if in its old age, is drawing too much current for the fuse to handle? ive seen this issue on this forum before. any other thoughts?

I have seen some OEM fans drawing 15 amps or a little more. Not seen anyone state their 20 amp fuse has blown.

A great tool to have is a clamp type DC current meter to check your fan currents. Test it with the engine running. Make sure if you buy one it says it can read DC current. Some of them only work with AC current.

[rustycarr]

My apologies, I misdiagnosed the problem in the midst of Easter holiday. The fan stopped working and I assumed the fuse.
I just checked for voltage at fan and I had 12v. The fan plug wasn't snug . Thanks for all the help,

[David T]

My apologies, I misdiagnosed the problem in the midst of Easter holiday. The fan stopped working and I assumed the fuse.
I just checked for voltage at fan and I had 12v. The fan plug wasn't snug . Thanks for all the help,

The OEM fans draw a LOT of current,especially when they both start. You can actually feel it in the gas pedal. One reason some owners have replaced them with Spalls or some other more efficient fan. Make sure all of your connections are good and tight and clean. Make sure you have the correct size fuses in each spot. The fan circuit is meant to only run intermittently, especially when you run the A/C. If the fans run continuously you will burn up the wiring. That is why the compressor MUST cycle and when the A/C compressor cycles it also shuts the cooling fans down. The Fan Fail Bypass was meant as a temporary fix, DMC never came out with a more robust relay to replace the Fan Fail Relay (which BTW lived up to it's name by reliably failing!). The aftermarket came up with alternatives like the Fanzilla. The better ones soft start the fans and sequence them so they both don't hit the electrical system at the same time. Some also have a delay built in so the fans will continue to run a bit even after you turn the engine off to reduce heat soak. You should consider getting rid of the Fan Fail Bypass and getting a relay from one of the vendors. Bitsyncmaster offers one too.