Glow plug indicator - burnt

[olthumpa]

When you turn the key to heat the glow plugs, what would cause the glow plug indicator to get bright red and burn out in a few seconds?

 

[D2Cat]

Defective part. Too much resistance in it and it overheats and becomes two parts. Similar to the heating element in your oven.

 

[olthumpa]

Defective part. Too much resistance in it and it overheats and becomes two parts. Similar to the heating element in your oven.

Thank you for your response D2Cat.

I can wire 110 220 volt residential and light commercial with out problems. Automotive is a not my strong suit.

The indicator is/was about 3 years old. I have just completed allot of rewiring on the tractor but did not touch the glow plug circuit, redid that when I replaced the indicator and plugs. Other than the indicator just letting go, is there any other thing that I should check - could cause it to burn up so quickly?

 

[85Hokie]

Thank you for your response D2Cat.

I can wire 110 220 volt residential and light commercial with out problems. Automotive is a not my strong suit.

The indicator is/was about 3 years old. I have just completed allot of rewiring on the tractor but did not touch the glow plug circuit, redid that when I replaced the indicator and plugs. Other than the indicator just letting go, is there any other thing that I should check - could cause it to burn up so quickly?

In your rewiring .....was everything put back into the circuit? The indicator "light" is simply a resistor - as it get hot, it is designed to "glow" - if another resistor was not placed in the line - or if the indicator was a type not able to handle the current and or voltage - it would burn up quickly. The "total" resistance of the circuit is very important - the glow plugs, each control the flow of resistance to the indicator - if one is off the others will take on the extra "heat" if that makes sense. Go back and double check the new plugs and the new/old indicator.

 

[D2Cat]

olthumpa, one would expect the coil to last longer then 3 years, more like 30 years.

There's 12V coming from the switch through the coil, then to the glow plugs. The glow plugs are wired in series. So if one connection is bad the circuit stops there. Make sure each GP wire has a good connection.

You can use a trouble light at each GP. With the switch on, so the GP's are getting power (CCW on my old tractors) you should have power before the coil, after the coil, and at each GP. This will tell you your circuit is working.

Since your GP indicator is burnt you could jump it with a wire and still do the test. It would also heat the GP's if you needed to start it. You would need to be careful to not leave the 12V to the GP's too long because it could burn them out.

Is the indicator actually burn so you can see a gap? Can you check it with an ohm meter, if not in 2 pieces to confirm it's an open circuit?

 

[olthumpa]

Thanks again to D2Cat and 85Hokie for your help.

The results:

Tested all the wires, plugs, connections etc and everything except the indicator checked out OK. When I changed the indicator 3 years ago, I kept the old one "just in case". Well, just in case happened. I took the new indicator out and sure enough the wire was in 2 pieces - fried. When I examined the new indicator, the wire was touching the side of the holder = dead short = fried indicator. Some how during my rewiring I must have hit it and moved the wire. Put the old one in, turned the key and it ssslowlly lit up. Hit the starter and the engine fired right up. Will still have to get a new indicator. The light for the tack did not light up but that will be easy to fix.

Thanks again for your help!

 

[D2Cat]

I bought one on ebay about 6 months ago. Here's a link.
http://www.ebay.com/itm/15231-65950...371?pt=LH_DefaultDomain_0&hash=item4ab3ebb313

I got it, put it in, but then found a wire to the GP's not making good contact. So I left the new one in, but I didn't really need it!

 

[olthumpa]

I bought one on ebay about 6 months ago. Here's a link.
http://www.ebay.com/itm/15231-65950...371?pt=LH_DefaultDomain_0&hash=item4ab3ebb313

I got it, put it in, but then found a wire to the GP's not making good contact. So I left the new one in, but I didn't really need it!

Thanks for the info. I need this one:
http://www.ebay.com/itm/Glow-Plug-I...232?pt=LH_DefaultDomain_0&hash=item1c48a5fdb8
Yours is a 20 amp and mine is 25 amp. Last time I got one there must have been a dozen on ebay now there is just one.

I have the solid wires between the plugs. While I was doing the rewiring I cleaned the ends up with a file to ensure I was getting a good contact.

 

[ShaunBlake]

When you turn the key to heat the glow plugs, what would cause the glow plug indicator to get bright red and burn out in a few seconds?

I think I know the cause, but first, a question: when you pinch your grandkids' cheeks, to they get bruised? I ask cuz I suspect you're 'bout twisting that key too hard. Aftermarket keys will twist in two, but Kub keys are stouter and will let you twist 'till your fingers hurt. (Don't ask! )

So, when you get yer new one, don't twist it so hard, and it might last the 30 years D2Cat guaranteez.

 

[D2Cat]

Shaun, on his tractor you turn the key clockwise. Then there is another switch to turn ccw to heat the GP's. Two different functions.