Blowing a fuse

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Mar 28, 2024 | 09:05 AM

Truckaholic

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Trailering

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Blowing a fuse

Interesting excursion stranding me story. I was on a 240 mile road trip and I pulled into a Safeway parking lot. **** the rig off and while the wife ran in to grab some food I just hung out in the car resting.

anyway when she came back the car went into a crank no start situation. Ok….checked the under dash fuses, the gem module fuse was blown. Alright, that’s weird. Autozone was right there (couldn’t have happened in a better spot really!) so I just grabbed a fuse pack and sure enough it fired right up, I hit the overdrive off switch and it immediately blew again, guess I know what I’m tearing into this week… I knew it was a maintenance issue, but it hadn’t bitten me til that trip.

I haven’t pulled up my diagrams yet, but judging by the immediate fuse blowing when the button was pushed I’m fairly certain it’s on the same circuit and taking down the power to the gem module.

Old rigs keeping life interesting!

Mar 28, 2024 | 11:05 AM

Vinny G-the EX man

More Turbo

Joined: May 2015

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From: Staten Island, NY

What number fuse blew, was it #45?

Mar 28, 2024 | 02:41 PM

Truckaholic

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Quote:

Originally Posted by Vinny G-the EX man

What number fuse blew, was it #45?

It was either fuse 19 or 20 on the “in cab” fuse box, I’d have to double check the exact placement of the new fuse. Im pretty sure it was 19 though. It only blew the second and third times when the overdrive cancel button was pushed-so I think that’s a pretty good clue.

Mar 28, 2024 | 07:29 PM

projectSHO89

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From: St Louis

You need to include the model year as well as the engine information.

Also, be specific about the fuse #.

Mar 28, 2024 | 07:52 PM

450kexcursion

Mountain Pass

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It is the wire harness in the shifter. It is a easy fix. Just electrical tape the rub thru and then wrap the whole loom. Take ya 30 mins. It is under the steering wheel.

Mar 29, 2024 | 02:59 AM

Truckaholic

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Quote:

Originally Posted by projectSHO89

You need to include the model year as well as the engine information.

Also, be specific about the fuse #.

Sorry, it’s a 2001 with the v10 gasser. I’d read all about the overdrive disabling shorts in the past and figured I knew what it was, especially since it re-presented itself two more times only when the button was pushed.

I guess I should have been more clear, I wasn’t really looking for troubleshooting assistance, I already had the lower half of the column trim taken off planning on getting to the known issue preemptively before it could bite me…and it just happened to get me before I took the upper section off and did the fix. I was too slow this time. I just had to buy a box of “emergency fuses” and drove 240 miles home, now it’s sitting there still waiting on me to fix it again. Maybe I’ll get to it this weekend.

Just posting as a cautionary/entertaining tale I suppose.

Both fuses on this model go to the gem module, what the reason for that is I’m not sure, but it was fuse 19 which is associated with the following: Instrument Cluster, GEM

Module, Overdrive Cancel

Switch, PATS/PATS

Transiever, Idle Validation

Switch (Diesel only)

Mar 29, 2024 | 06:40 AM

projectSHO89

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From: St Louis

FYI, on the earlier Super Duty trucks (inc Excursion), CJB F19 is the one that blows when the OD switch harness chafes and shorts. Later year models (starting in the '02 MY) moved that function to CJB F45 as Vinnie was suggesting.

If you fix the wiring harness, you'll likely be fine.