glow plug indicator coil melted!

[Mark schultz]

I have a unique problem. The glow plug indicator stopped glowing, and the tractor would not start. I ordered a new switch, and replaced it by attaching all wires exactly as they were on the old switch. While I was doing this, I put the charger on the battery. I reconnected the battery, and when I turned the key to the left, the glow plug coil immediately glowed, then the metal coil melted. When I turned the key to the right, the wires in the fusible link above the starter burned up. The local Kubota mechanic said that an old battery, when it oges bad, may put out more than 12 volts. I brought the battery in, and it tested at 12.4 volts. I bought a new battery, replaced the fusible link with a fuse holder and a 20 amp fuse, and when I turn the key, either to the left or the right, the 20 amps fuse blows. Does the fusible link allow more than 20 amps? Is there a short somewhere? I am really baffled.
Mark

 

[fj40dave]

I'd start tracing wires in the circuit, probably a short/ground problem.

 

[LRP]

i suspect that it,s not wired right. the glow plug indicator should be in series
with the glowplugs and will not melt down. u can make a glow plug indicator
with nichrome wire, old stove and clothes dryer elements.
LRP

 

[eserv]

Please tell us what model tractor we are working on. The glow indicator is rarely in series with the glow plugs on Kubotas

 

[LRP]

your are correct. some models they are not in series, but it looks like the older models they are and when the indicater is open, no glowplugs.
the wireing diagram for the L175, L185, L245 shows series and the glowplugs
themselfs are in series as well. anybody that has a tractor no mater what breed, should have a servicr manual.

 

[Mark schultz]

Many thanks to all who replied. I forgot to mention that it is a B8200D that I have. It is wired correctly, and I do have a service manual. I see nowhere in it , though, how many amps the fusible link is rated for, since I replaced it with a fuse holder. I guess my next step is to search for a short, but the switch is an exact replacement, all wires were put on as they were taken off the old switch, and are as the diagram in the manual shows. Since there were no shorts before, I'm very baffled.

 

[Theekillerbee]

Something is causing the glow plugs to pull too much power! Usually it takes a good 30-40 seconds before that coil is visibly hot enough to see in the light. Probably a short somewhere. Electrical problems can be a bear to troubleshoot. If that coil is melting, your glow plugs can also melt, you may want to verify their integrity, perhaps the problem is with one of the plugs.

 

[eserv]

I think thekillerbee is right. you have a short in the wire from the switch to the glow plugs, or the glow plugs themselves. Did something metal get left on top of the glow plugs shorting them? I don't have any info on the amperage rating on that link but I'd think it would be more than 20 amps seeing it has to carry the glow plug load. A bad battery put out to many volts? never heard of that before!!
ED

 

[Mark schultz]

Well I pulled the ignition switch out of the dash, turned the key to the left, and there was power to the glow plugs. I turned to the right, with the clutch pushed in to activate the safety switch, and the starter turned the motor over. When I put the switch back into the metal dash, the fuse blew as soon as I turned the key. I removed the glow plug indicator, thinking it might be shorting through that, but the short is through the switch body. All I can figure is that the new switch is defective?

 

[fj40dave]

Well I pulled the ignition switch out of the dash, turned the key to the left, and there was power to the glow plugs. I turned to the right, with the clutch pushed in to activate the safety switch, and the starter turned the motor over. When I put the switch back into the metal dash, the fuse blew as soon as I turned the key. I removed the glow plug indicator, thinking it might be shorting through that, but the short is through the switch body. All I can figure is that the new switch is defective?

Sounds like the problem is isolated to the swithch allright!
Could always just insulate the switch from the mount (rubber washers).

 

[eserv]

I'll bet one of the wires on terminal 17 of your ignition switch are touching the switch housing. if not then yes, you probably have a faulty switch.
Ed