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Hey Guys-
I got a strange on in today. I have a 2004 Ford Mustang with a 4.6L Mach 1. The complaint is when you turn the left blinker on, both rear lights blink as well as the parking lights, dome light, radio, odometer. When right blinker is turned on, it works correctly. Turn on the hazards, it goes crazy again. I've traced down most everything on the circuit, and everything is pointing to the Generic Electronic Module(GEM). My question is, does anyone know any inputs/outputs to be checked on the module or any test to confirm? Also does anyone know if this module is a module that has to be programmed when putting in a new one?
Ben wrote: Slow down check your left turn bulbs a single filament bulb where a double filament bulb belongs will cause that exact problem
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I also should have mentioned that this car had some modifications done to it such as racing gauges and a NOS kit installed. Which is why I was going in the direction that I was. When I get a car in like this, electrical issues usually point to the aftermarket wiring that had been done. In this case it doesn't look to be the issue.
I will certainly check the bulb in the back. I would have never thought of that. Thanks for the tip. I just don't understand how the dash lights and the radio are affected as well. I have poured over the schematic and nothing makes since on how this could cause all of the issues that I am listing. The bulb would certainly make since. If that is not the case, I have found some information in Mitchel on the inputs and outputs of the GEM. I certainty not calling it yet. I am checking for the multifunction switch as well, again thanks to both of you. I'll get back to it on Monday and will post the findings.
cheryl hartkorn wrote: im looking on wiring diagrams for a 2004 mustang with a 4.6 liter turn signals i dont see the gem related at all
What my thought was... The GEM controls the park lamp switch on pin 11. If these were shorted, it may give me the symptoms that I have. I know it's a reach but come Monday, I just want to take it out of the equation.
kona wrote: It looks like somewhere there is a bad common ground connection.
That was my first thought. I got excited because I tracked down G204 which is the ground common to all my issues. At first it looked like it had been arcing on the body when I removed it. But I cleaned it up and reinstalled everything and the problem persist.
I came in today to the shop with a clear head. First thing was to be positive the bulbs were correct. I then moved to the multifunction switch and was able to take that out of the equation. Bottom line is I went back to electrical troubleshooting and was able to find the wires shorted together (melted) in the harness on the drivers side. It was shorting the green/orange wire ( left turn signal) to the brown wire (park light). That was causing all the headache. Thanks everyone for the help with this!
Noah wrote: Seriously, nice catch.
What lead you to that location?
I started from the multifunction switch(making sure it was good) then I started isolating the lamps. I then isolated the front lamps from the rear lamps. Front lamps worked fine, everything worked correctly. Back lamps in, problem persisted. Then I just started following connectors, until I found it.
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