2001 Mustang Cobra - Strange Electrical Problem

[foofinator]

All,

I am restoring an auction-bought 2001 Mustang Cobra. The next issue I need to address is that I have no warning lights whatsoever on the right hand side of the cluster. It may be related to the fact that the cluster also takes around 15 seconds (consistently) to turn on after key-on. I replaced the cluster, and the replacement cluster did the same thing. I also had the car re-flashed in case there was an aftermarket tune; that didn't fix the problem either.

Anyone have any ideas about where I should look next?

 

[wmburns]

First. Are you positive the replacement cluster is from the same model year?

If this were my car and given given that that both clusters had the same symptoms I would rule out a problem right at the cluster connector(s).

CONFIRM the grounds at the cluster are able to carry larger currents. The grounds are the black wires and the black wires with white stripes. Test all the way back to battery negative.

As a reminder the cluster shares a ground behind the center console with a ton of other devices including the radio. This ground is frequently messed up during a radio install.

Howto perform charging system voltage drop test
https://www.stangnet.com/mustang-fo...perform-charging-system-voltage-drop-test.56/

Cluster PC foil trace repair.
http://www.allfordmustangs.com/forums/v6-tech/304608-my-odometer-goes-off.html#2657361

 

[foofinator]

All of the grounds checked out, including the black wire and the black and white wire.

I figured out how to put the cluster in test mode, it's giving me a 9356 code, which is ignition run circuit open. Notably, when it does the 'bulb' test, none of the bulbs light up. I put my new cluster back in and had the exact same results.

Any ideas where to look next? Was thinking about dropping the trim around the ignition switch to see if I can find any issues.

Strange thing is, the car runs and drives great now, and according to my scanner, does not throw any codes.. but it won't pass inspection if the stupid little CEL light doesn't flash. If I can't figure it out this week, I'm going to run jumper wires from the air bag light (which blinks on key on) to the CEL light and call it a day.

So close to finished, new top, wheels, brakes, suspension, interior, lights.. just needs some paint and have to sort out the AC.

 

[wmburns]

My Ford service manual calls out a "pinpoint test A" for a cluster DTC code 9356. Looking at pinpoint test A is basically a power and grounds test. However it does call out (3) different power and two grounds.

The bulbs on the cluster do burn out and are replaceable.

 

[foofinator]

Thanks wmburns. Using pinpoint test A, I found a wire that had been damaged by the previous owner. Looks like he tried to T something into it. Problem solved!

 

[wmburns]

This thread is a WIN for the "method based" trouble shooting. Much better than the "parts changing" method.

Good for you that you went through the effort to actually perform the tests and follow where the test results lead. IMO it's doubtful a wiring problem such as this would have been found using any other "method".