First off, great site. Lots of useful information. Sorry for what may be a longish post but want all the information out there.
Truck vitals: 2000 Excursion, 7.3L, 2WD; the VIN reports this as a 5.4L gas engine so it was swapped. I learned this after the purchase. All my fault, I wasn't reading the CarFax clearly; I had Excursion Fever. From all I can see the swap was done well. The truck has run fine, just has some electrical gremlins I've been chasing. Truck came with an after market key fob but the door electrics weren't working well so I pulled it out. Door electrics still an issue with locks not working. I also had (keyword, had) the 5x5 beeps telling me the SRS light was out. Changed the bulb and still get it. I blame the flex circuit on the back of the instrument cluster as it seems a bit chewed up light 50 people have changed the bulb. The headlights take about 10 sec to come fully on, and activating the hi-beam function turns the headlights off. The ABS light is always on. The steering wheel function buttons don't work. Fun. Also, I lost the transmission pulling the RZR home, luckily a friend in his 2005 Excursion was able to get the trailer home for me. So, new transmission. Ok, that's the general back story of this particular truck. The engine runs smooth and seems ok. I'm ok with a lot of this and looked forward to the challenge to fix them over time as a lot are what I'd call nuisance issues.

I've replace the CPS, EBP sensor and tube, cruise control release switch and cable, instrument bulbs and gear selector bushings.

I've been chasing a power drain. My batteries would be flat after sitting a day or two. Replaced with 2 new Autozone Duralast Gold. Things seemed better (the old ones were Interstate Value Series that were a few years old) but still getting a power drain. About two weeks ago I replaced the alternator with a new, not reman, Duralast 110A model thinking it could help with batteries dying. Fast forward to last week and truck wouldn't start, dead battery(ies). After jump starting I took the truck to Autozone and had them test the batteries. Long story short he didn't test them right (didn't isolate the batteries) and they gave me a new battery when his device said one was bad. Overnight truck dies <--- still no clue what caused this, possibly 1 horrible battery that pulled the other down. Took both batteries out and took to Autozone. Both tested good but under voltage. They charged them both, damaging 1 (too hot to handle) and replaced it. So, 2 new batteries and new alternator. At this point I suddenly realize I'm not getting the 5x5 beeps for the SRS light each time I start the truck.....go figure.

Now I'm starting to look for the power drain again (remember, new batteries and alt). Isolated the passenger battery and disconnected the passenger side ground. Hooked in my voltmeter and it read 350mA or so. I started pulling fuses and none in the engine compartment did anything. Moved to driver side fuse panel and fuses 14 and 15 registered on the voltmeter, each reducing to 50-70mA. I plugged the fuses back in after pulling and moved to the next. I've read different ways to do this so not sure if this is to blame. I assume pulling fuse 15 (Stop Lamp Switch (Logic), PATS, GEM) would generate a large drop due to what I assume is it being the brains of the operation. Fuse 14 is interior lights, mirrors and windows.

As I'm trying to figure this all out I had to go to my kids baseball game. Climb in and the air ducts are stuck on defrost (I live in Arizona and it was 100* out), the rear ducts would not discharge nor would the rear controls in the roof operate anything. Add to this, if the front blower is on the blinkers or brake lights won't work. So I drove with only the defrost on. I pulled fuse 14 in my power drain search so the windows wouldn't go down. More fun.

I searched around and thought the vacuum pump was dead. Replaced it and still nothing. Probed the connector with KOEO with my circuit tester and I get both red and green lights so I think it's getting 12V. When I probed with with my voltmeter I only got 3.7V (I need to use different probes, not sure if I really contacted the pins well) at the connector. All fuses both in the engine compartment and driver side cabin are good (though some wiggle a little....). I'm just staring at the Excursion and shaking my head. I can deal with a small issue here, small issue there. Having them pile on me is confusing me.

Sorry to bore everyone but I'm at a loss. Several seemingly unconnected (pun intended) issues that I'm hoping someone can help point me down a troubleshooting path. This not being my specialty I tend to troubleshoot everything at one time and never drill down on just one. Any ideas on where to start?

 

Whew, that sounds like a lot. Since no one responded, I would recommend you inspect the interior fuse box (Central Junction Box) behind the drivers side dash cover for any water damage. Any evidence of a leaking windshield?

 

Yes, it was a lot of info but I felt it better the whole story is out there.

Thanks. I'll do that. I've read about that issue but being in AZ I guess I've discounted that as a place to look. Not sure how hard it is to pull the fuse box out but I'll give it a try. I already have to sit on the running boards to do anything in that area. And I don't twist well.

Tonight I'm going to see if I can power the pump via a power probe as well, see if I can at least find the direction of the issue. But I'm starting to think you are correct that my issues lie in and around the drive side area. That area is a rats nest of cut and spliced wires to add aftermarket radios, electronic brake controllers and keyless entry systems. If it didn't look so scary, and I didn't have to invert myself to look, I would have traced several of those wires. But since that's a skill I need to acquire it may be some time before I can do that. Plus find the time.

Thanks again.

 

Smartest thing to do at this point is to buy the wiring diagrams for the whole truck...about $20 on eBay last time I looked.

 

Good idea. Thanks. Was searching all over for them.

 

Just an update, hopefully less than 4 pages.
1) Power drain: Re-did the power drain test, this time probed the back of the fuse for mV and converted to mA using the online resources.
- result was 277mA vs the ~350mA I reported above
- Fuse 14 (interior lights) and 15 (GEM, PATS) were still the culprits. I flipped the door latches and let the truck sit an hour. Answer was the same waiting 2 min and 60 min.
- I pulled all relays and no change (except battery saver relay and junction box relay as expected since these cut power to the fuse block)
- I pulled roof console and unplugged all interior lights (minus doors), unplugged all door switches (power mirrors and windows). No change.
- Gave up and moved to vacuum pump
2) Vacuum pump
- Borrowed a Power Probe
- hooked up to battery, alligator clip to vacuum ground and probe tip to positive terminal. It fired up and operated.
- Probed the 2 cable pins. Both registered with a green light, which I take to mean grounds. Probed through the insulation on both lines as they exit the connector and got a green light. The connector appears good.
- looked around looking for something obvious. Gave up.
3) Back to Fuse Box.
- as suggested I was trying to look for evidence of water intrusion. Didn't see anything.
- I pulled Fuse 14 because I was done for the day and this is how I've been trying to prevent my batteries from draining the last 2 days. Friend called and asked for a ride somewhere.
- I put Fuse 14 back in and heard what I'd call electrical crackling like you hear when touching jumper cables together. No other fuses have made that noise that I'm aware.
- Something is amiss and I'm thinking I need a new Fuse Box as there's clearly a short or something in it. I don't remember hearing this noise the dozens of times I've pulled that fuse the last few days looking for my power drain.

I'm giving up and going camping this weekend. The saga will continue next week.

 

You say you pull 14 to fix issue? Are all your doors closing? The door switches are a common issue with these rigs.. It also could be your battery saver relay which is located where your flasher relay is (this is what fuse 14 powers).. But if doors are not closed it wont go into battery saver mode... Battery Saver Relay

 

I pull Fuse 14 and 15 because that's where the power draw is. I checked again just to satisfy myself this morning. When I pull Fuse 14 there's no change in the draw from Fuse 15. When I pull 15, Fuse 14 goes to 0.000 mV. Makes sense to me since Fuse 15 (GEM) controls the lights.
My only verification that doors are closed is there's no Door Ajar light (fought that when I bought it, rear hatch wouldn't close the switch) and the interior lights turn off. Is there another method to verify this?
Thanks, I'll look into the Battery Saver relay too when I'm back form camping. I assume that's one of the relays in the engine or passenger compartment fuse boxes? I'm not searching for another box that I'm unaware of?

 

Is it not a very common thing for the GEM module to get shorted out and need to be cleaned and re-assembled on these trucks guys?

If the fuse for the GEM is what is pulling residual load, and nothing else solves it, maybe the GEM itself is the culprit, seen it before.

I seriously advise against disassembling the GEM yourself, it is complex and delicate, there is a website you can go to and if you send your GEM to them, they will rebuild it, repair anything wrong with it, and ship it back stupid fast.

My GEM module has been solid so far, but i am dreading if I ever have to mess with the damn thing.

 

You might be thinking of the central junction box...the GEM is a small plastic box with one circuit board in it that is piggy backed to the left side of the CJB.

 

Do you have the website? I’ll look around as well. I’ve been thinking of doing this just to get a “reset”, know it’s working. I hope they won’t want my VIN since it says it’s a 2000 5.4L. I looked at the fuse box PN (1C7T-14A067-AN) and the date is 2/2001.

I also pulled the Battery Saver Relay before I left for the weekend. It was pretty warm to the touch. Is that normal?

Thanks everyone.

 

You sure about that?

A little reference on this evil POS
https://www.ford-trucks.com/forums/1...ater-leak.html

 

Yes, I am sure about that. That thread is all about a CJB tear down and rebuild. He does not rebuild the GEM in there. The GEM is plastic...it is well sealed, and it is on the upper left side of the CJB. It plugs right into the side of the CJB even...above where the water leaks in through the two CJB plugs and into the box itself.

 

Here are pics of a 2000 V-10 CJB and it's tag along GEM

 

OP is camping this weekend, or he would likely be asking you to grab all that for him.