Engine Harness Replacement
#1
Engine Harness Replacement
Has anyone had to replace the complete engine harness and what has to be removed
**Alternator caught on fire and meted harness back under intake of engine,
Was driving and had a rotten egg smell but thought it was car in front of me, must have been alternator over charging batteries. Stopped for lunch and as i pulled in heard a bearing noise, assuming water pump or idler pulley. Came out after lunch to smoke pouring out wheel well and hood, was glowing at alternator and couldn't put it out, disconnect batteries and then got snow on it to put out. Looks like maybe diode shorted out and heated up to cause fire but not enough current to blow fuse-able link in alternator to battery connection.
Fire damaged; alternator, belt, A/C line, Wire-Harness melted back into intake area, hard plastic line (looks like vent)
Dose cab have to come off?
I've also have had fuel pump volume control codes come up 2-3 time during hot weather while at running temp and accelerating so might be a good time to replace it if cab has to come off now?
2010 F350
6.4L
215,000
Deleted / Spartan Tunes
**Alternator caught on fire and meted harness back under intake of engine,
Was driving and had a rotten egg smell but thought it was car in front of me, must have been alternator over charging batteries. Stopped for lunch and as i pulled in heard a bearing noise, assuming water pump or idler pulley. Came out after lunch to smoke pouring out wheel well and hood, was glowing at alternator and couldn't put it out, disconnect batteries and then got snow on it to put out. Looks like maybe diode shorted out and heated up to cause fire but not enough current to blow fuse-able link in alternator to battery connection.
Fire damaged; alternator, belt, A/C line, Wire-Harness melted back into intake area, hard plastic line (looks like vent)
Dose cab have to come off?
I've also have had fuel pump volume control codes come up 2-3 time during hot weather while at running temp and accelerating so might be a good time to replace it if cab has to come off now?
2010 F350
6.4L
215,000
Deleted / Spartan Tunes
Last edited by vlietracer64; 02-15-2019 at 02:42 PM. Reason: add
#4
I dought that your pcm is any good so I would check into that.
the pcm looks like it would be simple to pull out and have it tested .
short circuits and electricity do not play well together
did any fuses blow
this fire starting due to alternator Buisness does happen frequently on these trucks .....some one needs to design a fail safe that would prevent this.
i saw a product once that looked like a hose that you would snake around the engine and if it gets hot, it acts like a fire extinguisher. I may have to look into that
there are at least 2 fuseable links in that system so you will probally need those as well.
good luck and keep us posted
the pcm looks like it would be simple to pull out and have it tested .
short circuits and electricity do not play well together
did any fuses blow
this fire starting due to alternator Buisness does happen frequently on these trucks .....some one needs to design a fail safe that would prevent this.
i saw a product once that looked like a hose that you would snake around the engine and if it gets hot, it acts like a fire extinguisher. I may have to look into that
there are at least 2 fuseable links in that system so you will probally need those as well.
good luck and keep us posted
#5
if that 08 had a dual alternator setup I would be interested in the upgrade brackets, harness, etc for the second alternator located at the top. The top is referd to as the primary in a dual setup . For us with single setups with alternators at the bottom oh wheel well side that’s the secondary position. I have the secondary located at lower pax side wheel well with empty primary located at the top.
#7
it was definitely the alternator that started it. I threw snow and tried to blow out flames from wire harness and the back of alternator was glowing and kept re-igniting plastic on back and split loom on wires. Once I disconnected batteries the glow stopped and I was able to put fire out with snow for good. I’m guessing a diode shorted out allowing batter voltage and current into windings causing a short that heated up bad diode till point it started windings and plastic endcap on fire. Guessing fuseable link didn’t blow cause it is sized for max alternator output and short that cause fire was Under said amperage.
Should have more pictures tomorrow
fire heated aluminum A\C line till it split and burst
Should have more pictures tomorrow
fire heated aluminum A\C line till it split and burst
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#9
At first though was thinking to put a 400 amp diode in series with alternator and battery. That way if any of the alternator diode failed, the new in line would prevent reverse voltage. But it would probally be better to just use a large battery isolator ....they are rugged and dissipate heat better.
#14
I didn't realize that those alternators had that issue. Once the diodes shorted to ground it was all hell breaking loose. The one way to tell where a short starts is to follow the burned wiring. Since it burned back and including the alternator it's obvious where the fire started. The bad part is those wires burn in the loom which causes other wires to burn and short to their power sources and the next thing you know you have a major mess. If you have insurance it should cover the burn damage but not the alternator. Usually they won't cover the cause but will cover the damage. You might want to check into that. JMO
#15
I didn't realize that those alternators had that issue. Once the diodes shorted to ground it was all hell breaking loose. The one way to tell where a short starts is to follow the burned wiring. Since it burned back and including the alternator it's obvious where the fire started. The bad part is those wires burn in the loom which causes other wires to burn and short to their power sources and the next thing you know you have a major mess. If you have insurance it should cover the burn damage but not the alternator. Usually they won't cover the cause but will cover the damage. You might want to check into that. JMO
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MR KROGOTH
1987 - 1996 F150 & Larger F-Series Trucks
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08-31-2021 09:54 PM