Glow Plug question

[Mudball]

My glow plug does not light up through the hole unless I cant see it because its too dim. I hold the switch in the glow plug position for (counting seconds in my head) about 10 seconds and then the tractor starts fine. Should I get a new glow plug anyway ?
I checked the voltage on the back terminals and it was somewhere around 10V and on top of each glow plug itself there was around 8.5V
I also noticed that after the switch is left in the same glow plug position that after several seconds the voltage slowly dropped off down to 0V.
So I guess there is some kind of thermal protection ?
Just keep holding switch in position for 10 seconds or more or order new glow plug switch ?

 

[85Hokie]

My glow plug does not light up through the hole unless I cant see it because its too dim. I hold the switch in the glow plug position for (counting seconds in my head) about 10 seconds and then the tractor starts fine. Should I get a new glow plug anyway ?
I checked the voltage on the back terminals and it was somewhere around 10V and on top of each glow plug itself there was around 8.5V
I also noticed that after the switch is left in the same glow plug position that after several seconds the voltage slowly dropped off down to 0V.
So I guess there is some kind of thermal protection ?
Just keep holding switch in position for 10 seconds or more or order new glow plug switch ?

What machine? older machines - like you are describing, you will need to hold the button a wee bit longer to see the coil glow. On my B7100 - in dim light, I need to hold the key for 30 seconds or so to see it begin to light.

 

[Mudball]

Thanks 85Hokie.
Sorry I forgot to say L245F.
I will have to check that again about the glow plug.
I cant find in any of the manuals, a description of how long to hold the glow plug switch. I can only find where they say to use them in cold weather. I have to hold mine for at least 10 seconds before it wants to start correctly and its hot outside.

 

[North Idaho Wolfman]

What your looking at in the dash is not the glow plug it's the glow plug indicator, real simply a heating element, If any of the 3 glow plugs in the head are bad the glow plug indicator will not glow.
First remove the wire on all the glow plugs and use an Ohm meter to test each one, they should be in the 1 to 8 Ohm range, infinite or high Ohms and it's dead, 0 ohms and it's a dead short.
Also the glow plug indicator can be bad, but if your getting power to the glow plugs in the head then it should be fine.

These are the glow plugs:

 

[85Hokie]

Thanks 85Hokie.
Sorry I forgot to say L245F.
I will have to check that again about the glow plug.
I cant find in any of the manuals, a description of how long to hold the glow plug switch. I can only find where they say to use them in cold weather. I have to hold mine for at least 10 seconds before it wants to start correctly and its hot outside.

go out there at dusk, and hold the key/button for 30 seconds.......tell us she glows!

I hit mine on my 23 year old tractor for 10 seconds in the summer, and the 2013 BX for at least 5 seconds. Winter I triple that

 

[Diydave]

You might also have a connection problem. Check each GP's connection to the bus bar, and all other connections...

 

[Mudball]

Thanks for all the great help.
The glow plug indicator did not light up/glow.
Im sure I will get some time to check some more out today.

Even if everything is working perfectly then what is the correct method or procedure to start ?
Turn glow plug switch until light goes off/on then start ?

 

[D2Cat]

Turn your switch counter clockwise and hold for 15-20 seconds (20-30 in winter). She should fire off then.

If GP's get juice the GP indicator is OK. It's like a BIG fuse, electricity has to go through it to get to the GP's.

If one connection on a GP is faulty, or the plug no good, power will flow no farther, so any thing past the bad circuit will not function.

 

[Mudball]

Got it. Sounds great.
Thanks.

 

[olthumpa]

What your looking at in the dash is not the glow plug it's the glow plug indicator, real simply a heating element, If any of the 3 glow plugs in the head are bad the glow plug indicator will not glow.
First remove the wire on all the glow plugs and use an Ohm meter to test each one, they should be in the 1 to 8 Ohm range, infinite or high Ohms and it's dead, 0 ohms and it's a dead short.

While you are at it, take the time to clean the connections on part #16 and also the wire leading from the glow plug indicator to the glow plugs, (at the glow plug end) .

Also the glow plug indicator can be bad, but if your getting power to the glow plugs in the head then it should be fine.

I had a similar/same problem as you describe on my L275. The glow plug indicator was VERY dim, (could not see it glow unless it was dark). Voltage checked ok, cleaned all connections and found one bad glow plug. Replaced all the plugs but problem persisted. Shortly after, the glow plug indicator shorted out. I replaced it and everything worked great. So I had two problems, one bad plug and a failing indicator.

These are the glow plugs:

Sorry to hijack Wolfman.

 

[North Idaho Wolfman]

Sorry to hijack Wolfman.

Not at all, great info!

 

[Mudball]

Thanks for all the great help. They seem to be fine now but I will certainly keep an eye out.
I did clean the connections on the glow plugs but I left the indicator connections alone.
That one glow plug at the front of the engine is hard to get to. I guess a person must disconnect the fuel line if you wanted to remove it ?
Either way I will cross that bridge when I get to it.
Thanks again.

 

[North Idaho Wolfman]

One little note:
It's much easier to replace/repair parts/equipment in the summer than it is to replace/repair parts/equipment in the cold of winter, and that is when you will need the glow plugs to work.

 

[Mudball]

I will certainly keep that in mind.
Karma gets me every time.
Thanks for the info.