Looking for causes (ECM or Ignition Switch)

[dpetrlak]

Having a very strange problem with my '02 7.3. Truck as 305k on the clock so it's been driven.

So often my truck starts JUST FINE, but it looks like some type of Aux power is not coming on.

Tell tale indicator is the after market Radio/NAV not powering on, (which has power of some kind as it has a blinking power light) at the same time the windows won't operate. Then..... 2 min, 3 min, been as much as 10 minutes and the circuit that powers the radio and windows circuit is completed and the radio comes on and the windows work.

Now the AC/Heater seems to work. I have toggled with the Ignition Switch and I don't think that would be a logical place. A few years ago, I did have an issue where there was NO Aux power including the AC, etc and the only thing that worked was to shut it off and restart, jiggle the key, etc. But that was very intermittent.

Knowing all the wires that are connected to the ignition switch, I have given that some consideration, but since there is a VARIABLE time delay, IF/When this occurs my guess is that's not the cause.

Anyone run across this issue before? Any possible solutions?

TKS

 

[01yellerCobra]

I haven't had this issue, but I do know in my truck there is a delay before the windows and such work. There's a click under the driver seat after its moved forward and thats when everything works. I'm assuming it's a switch or relay having to do with the easy entry option. If you don't have that I would look into the GEM. If your truck has one. But the way it takes time makes me think a relay somewhere is getting slow.

 

[dpetrlak]

Could be. I'm not familiar with all the relay's, but read that there are a bookoo of them. Good idea.

 

[2HawkFans]

Do some Google searches (may actually be here that I found the information) on your year and body control module or vehicle security module. I had similar symptoms on my '02 and that's what it was.

In my case however there were a few more signs of something not right other than the radio not coming on and the power windows not working for random intervals when starting. I had issues with door ajar light always being on. So even when I turned the truck off and opened the door the radio would continue to play. If the truck sat for a few weeks it would also drain the battery. My electric door locks wouldn't work at the interior switch nor the key FOB. My truck has auto sensing feature to automatically turn on the headlights at dusk as well and that feature didn't work.

There are some outfits that can rebuild modules. A friend suggested one that did a Saturn ECM for him with good results. They told me my module had shorted and couldn't be repaired. They offered a replacement but it was nearly $500. I found one on ebay out of a wrecked truck for $80, installed it and then took it to the dealer to download the build data for my truck and program the module and now everything works again.

Like I said, mine showed many more symptoms to lead me to the module. So that may not be what's up with yours but something else to consider.

Brad

 

[RSG]

My '02 had the same exact problem. Totally intermittent, it would go months w/o doing it then act up. I did have a short caused by a wire in the steering wheel base getting insulation rubbed off, but that would cause a dead short. Fixed that but this power window/radio thing never did get sorted out. I suspected the cluster on the driver door because the passenger side windows would work even when the driver side switch didn't.

 

[predatorproblems]

My '02 had the same exact problem. Totally intermittent, it would go months w/o doing it then act up. I did have a short caused by a wire in the steering wheel base getting insulation rubbed off, but that would cause a dead short. Fixed that but this power window/radio thing never did get sorted out. I suspected the cluster on the driver door because the passenger side windows would work even when the driver side switch didn't.

Sometimes water will leak through the windshield seal on drivers side and drips right into the truck and goes right to GEM. It’s located above the fuse box and when wet causes all sorts of crazy stuff. Next time it rains stick your hand up in there on top of the GEM and if it’s wet you found the problem. Seal the windshield good.


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