Keep blowing 10 amp fuse on my Emax22

[SedonaDave]

That light bulb in place of a fuse is a technique taught by ford technical training to dealer techs. It works well. I have used it as a tech and a field service engineer.

And saves fuses!!!! LOL......First did it with light bulbs in old fuse pannels looking for shorts.....Same thing!

 

[tjkubota93]

And saves fuses!!!! LOL......First did it with light bulbs in old fuse pannels looking for shorts.....Same thing!

Oh, those were before my time but it makes perfect sense. When I was small I was at my grandad's house. A fuse blew and my dad was kinda piturbed because grandad wanted to put a penny in there (not having a fuse)

 

[dickfoster]

My tractor is a little over 2 years old so is off warranty now. Kept blowing the 7.5 amp fuse on the pto and my dealer finally figured it was the pto relay. Then I started blowing the 10 amp fuse on the wiring harness. My dealer has changed the fuel solenoid twice now. The last time he changed it my tractor worked about 6 hours before the fuse failed again. They said they checked the wiring harness for shorts and found none. They have no idea what's causing this. This coming week will be the eighth week I haven't had use of the tractor this summer. Has anyone here had a similiar problem? Any ideas would be greatly appreciated.

I'd place my bet on a frayed wire somewhere that it shorting to the frame. This is by far the reason most fuses blow in mobile equipment like cars, planes, tractors etc. BTW that is why fuses are there in the first place, to prevent the equipment from catching fire and burning due to shorted wiring.

 

[RNeumann]

I'd place my bet on a frayed wire somewhere that it shorting to the frame. This is by far the reason most fuses blow in mobile equipment like cars, planes, tractors etc. BTW that is why fuses are there in the first place, to prevent the equipment from catching fire and burning due to shorted wiring.

You and I are thinking the same thing. Manually moving/manipulating the wires will typically reveal the short fairly quickly.
Light bulbs, "testers" and the like are way down the diagnostic tree in my world.

 

[Spanner]

You and I are thinking the same thing. Manually moving/manipulating the wires will typically reveal the short fairly quickly.
Light bulbs, "testers" and the like are way down the diagnostic tree in my world.

Au contraire. The light-bulb idea is a good way of finding the short-circuit (We all agree there's an SC) when he 'manipulates' the harness.

Otherwise he'll just blow lots of fuses narrowing down the location of his problem.

Diagnostic 'tools' are a long way up the diagnostic tree in my world.

 

[SedonaDave]

Au contraire. The light-bulb idea is a good way of finding the short-circuit (We all agree there's an SC) when he 'manipulates' the harness.

Otherwise he'll just blow lots of fuses narrowing down the location of his problem.

Diagnostic 'tools' are a long way up the diagnostic tree in my world.

I totally and completely agree....Unless you can by fuses by the gross!

 

[RNeumann]

Coffee is on. Come on down to the shop. I've got a fleet of fire engines, staff vehicles and other support vehicles. Take your pick. Probably have over 1000 circuits to choose from- just a staff SUV must have over 100 with light bars, radios, MDCs etc.
Your first post in this thread (maybe about post 3) is partially accurate. But waiting for it to short again doesn't cut it in my world. A fuse gets replaced once but if it blows again the issue should be found.
One must "create" the intermittent circumstances to find the issue. Seems over 90% of the time (as Dick stated), in a vehicle, motion/movement is what's causing an intermittent problem.

So, hypothetically speaking, if someone brought me a vehicle with an intermittent radio or a radio that was blowing fuses, the first thing I'd do is smack the side of the radio to see if something inside the radio was creating the problem. (One second) Then I'd grab the wires/wire harness leaving the radio and yank it around (10 seconds) then it's time to move beyond the cab and deeper in the harness- again moving the wires/harness as I went (maybe a minute or two). In this example I'd spend more time pulling up wiring schematics and hooking up the Fluke meter than I would actually diagnosing the issue!

Maybe I'm missing what the OP is asking but it seems a lot of theory about diagnosing has occurred with little offered about how to isolate and fix the issue. A tractor isn't that complex- it's only got about 20' of main harness-if that. This shouldn't be that tough to find.

 

[SedonaDave]

Coffee is on. Come on down to the shop. I've got a fleet of fire engines, staff vehicles and other support vehicles. Take your pick. Probably have over 1000 circuits to choose from- just a staff SUV must have over 100 with light bars, radios, MDCs etc.
Your first post in this thread (maybe about post 3) is partially accurate. But waiting for it to short again doesn't cut it in my world. A fuse gets replaced once but if it blows again the issue should be found.
One must "create" the intermittent circumstances to find the issue. Seems over 90% of the time (as Dick stated), in a vehicle, motion/movement is what's causing an intermittent problem.

So, hypothetically speaking, if someone brought me a vehicle with an intermittent radio or a radio that was blowing fuses, the first thing I'd do is smack the side of the radio to see if something inside the radio was creating the problem. (One second) Then I'd grab the wires/wire harness leaving the radio and yank it around (10 seconds) then it's time to move beyond the cab and deeper in the harness- again moving the wires/harness as I went (maybe a minute or two). In this example I'd spend more time pulling up wiring schematics and hooking up the Fluke meter than I would actually diagnosing the issue!

Maybe I'm missing what the OP is asking but it seems a lot of theory about diagnosing has occurred with little offered about how to isolate and fix the issue. A tractor isn't that complex- it's only got about 20' of main harness-if that. This shouldn't be that tough to find.

A fuse will only do 2 things......Cut out on a short, or over current protection.....Who in the world would think any relay could blow a 10 amp fuse?

Pull that fuse, look at wiring diagram....Check those wires to ground with continuity, tractor running and off.....Sound just like a shorted or pinched wire......Eventually it will totally fail!

This is what I offered, and do agree that the harness cant be 20' away from spine.....But completly disagree with a intermintet electrical possable short!..You do know if you use a lamp, you can see the light! Then you know your close.....You need to keep going back to fuse box and see if it tripped.....To each his own.....But ive seen things you could never imagine happen just from back feeds.

 

[tjkubota93]

Coffee is on. Come on down to the shop. I've got a fleet of fire engines, staff vehicles and other support vehicles. Take your pick. Probably have over 1000 circuits to choose from- just a staff SUV must have over 100 with light bars, radios, MDCs etc.
Your first post in this thread (maybe about post 3) is partially accurate. But waiting for it to short again doesn't cut it in my world. A fuse gets replaced once but if it blows again the issue should be found.
One must "create" the intermittent circumstances to find the issue. Seems over 90% of the time (as Dick stated), in a vehicle, motion/movement is what's causing an intermittent problem.

So, hypothetically speaking, if someone brought me a vehicle with an intermittent radio or a radio that was blowing fuses, the first thing I'd do is smack the side of the radio to see if something inside the radio was creating the problem. (One second) Then I'd grab the wires/wire harness leaving the radio and yank it around (10 seconds) then it's time to move beyond the cab and deeper in the harness- again moving the wires/harness as I went (maybe a minute or two). In this example I'd spend more time pulling up wiring schematics and hooking up the Fluke meter than I would actually diagnosing the issue!

Maybe I'm missing what the OP is asking but it seems a lot of theory about diagnosing has occurred with little offered about how to isolate and fix the issue. A tractor isn't that complex- it's only got about 20' of main harness-if that. This shouldn't be that tough to find.

If you replace the fuse in the suspect circuit with a light bulb (can even wire in parallel with a buzzer) when you yank the harness in such a fashion to reproduce the short to ground the light bulb and/or buzzer goes off. And your right, it takes 30 seconds.