Electrical Gremlin

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Jul 15, 2019 | 11:29 AM

bmoran4

Thread Starter

Parts Nerd Extraordinaire

Joined: Sep 2010

Posts: 4,327

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From: Western NY

Electrical Gremlin

Drove the truck a couple hundred miles over the past few days only to have it misbehave 30 miles from home.

All the sudden, without warning, the engine sounded like I pulled the choke bout too far. An immediate scan of the cluster showed the amp meter at Max discharge. I limped sputtering a 1/2 mile to an intersection with a gas station and immediately popped the hood. Nothing obvious. I disconnected the positive ground battery cable which was sparking as I did so indicating a nice big load (presumably a short).

Now for the questions - why would a short cause the engine to behave poorly?

Any place to look first for such a short (generator, voltage regulator)?

Vehicle is fused and has stock breaker. None blew or tripped.

This is a stock F6 with 239 V8.

Jul 15, 2019 | 11:40 AM

Moe Craig

Cargo Master

Joined: Sep 2010

Posts: 3,426

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From: Hot AZ (Phoenix Valley)

If it's grounding enough to starve the engine of electrical power it will run poorly!

Jul 15, 2019 | 12:18 PM

Mixer man

Logistics Pro

Joined: Sep 2014

Posts: 4,920

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From: Bothell & Silverdale, WA

If it's not tripping breakers or blowing fuses the problem is upstream of those. I suspect a wiring short and/or a defective voltage regulator/generator. The fact that you are getting a heavy discharge suggests that your ground connections are good. Test the voltage at the coil.

Jul 15, 2019 | 12:23 PM

ALBUQ F-1

Fleet Owner

Joined: Jul 2004

Posts: 27,283

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From: NM

Check the wire going thru the ammeter loop for shorts. I would expect you'd smell or see smoke tho. Check all the connections on the circuit breakers, too.