L260 glow plug wiring

McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
Now that it's getting cold out I need to get no glow plugs working. I was able to start it ok in the summer without them, but obviously not now. Anyhow, I think I narrowed it down to the ignition switch. When I turn it counterclockwise to activate then nothing happens. I cheers l checked continuity on the terminals for them & there isn't any so I'm guessing the switch is bad. The weird thing is there's an extra button in the circuit that I don't think belongs. Attached is a pic of it. Seems like it's have to press it when trying to glow. Is this correct or is it supposed to be an indicator and someone put a button there instead?
Also, how do I get the switch out? There's a brass nut looking ring under the lever but it's completely round with little holes at 12 and 6. I thought there we're set screws in them but I couldn't find them. Turning it only turns the whole thing. Should I just put penetrating oil on it to loosen it up or am I missing something?

Thanks!

Mike


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85Hokie

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BX-25D ,PTB. Under Armor, '90&'92-B7100HST's, '06 BX1850 FEL
Jul 13, 2013
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Bedford - VA
Despite the fact that it has been "rigged" ......does the tractor start when this button is pushed for 10 or more seconds?

Follow those black wires...where do they go?
 

McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
Nope. The button seems to work, it had continuity when pressed but the ignition switch doesn't have continuity when rotated counterclockwise.
In the pic, the two wires on the left go to the push button.


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Russell King

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Equipment
L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
4,603
975
113
Austin, Texas
It has probably been rigged up to turn key to on, push button to heat glow plugs release button then turn key to start position.

See if it works that way.

Probably the ignition switch is bad.

On my L185 the key switch just turns circuits on. There is a separate knob switch to power the glow plugs with left turn and then starter to the right turn.

There is a glow plug indicator that is behind a hole in the dash. It is a resistor coil in line with the glow plugs


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McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
I've tried that too. I think it was set up that way but something went bad. When I got it the owner said the button had recently stopped working.
It is supposed to work like your 185, but was Jerry rigged at some point. I think I'm just going to replace the starter switch and glow plug indicator & put it back to stock.

Thanks,
Mike

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Dave_eng

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Equipment
M7040, Nuffield 465
Oct 6, 2012
5,107
926
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Williamstown Ontario Canada
The wiring for the GP's on older tractors is often messed up by previous owners who really do not understand how the GP's are designed to work.

Some GP's are wired in series and others in parallel. Your L260 should be wired in parallel.

Each glow plug gets its electrical ground from contact with the block. Some owners have found that rust was inhibiting the electrical ground.

They had to remove and polish up the mating surfaces.

This block diagram of a key switch may be meaningless to you but it contains one important detail for proper GP operation.

The GP's remain powered up as the engine cranks!!!

Terminal 30 is the power supply to the switch and terminal 19 feeds the GP's. Terminal 50 engages the starter. the START line shows terminal 19 is powered as the engine cranks



This is why a correct key switch is important.

Post some photos showing the side of your engine where the GP's are.


The key switch ring with small holes in the side should unscrew. Cut it with a dremel tool if you have to.

Probably a good idea to buy a new Glow Plug indicator along with the key switch. About $20

https://www.ebay.com/itm/Glow-Plug-...h=item25e0e3c364:g:4kcAAOSw6TdbnC84:rk:6:pf:0



Dave
 

McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
Well, I bought a new switch and glow plug indicator & put them in today. Still didn't work though. I'm not seeing the indicator glow either.
I pulled the plugs out & one of them is broke! I'm guessing they are both bad as I didn't get any resistance from either before I pulled them. Would that keep the indicator from glowing?
One of the wires from the indicator goes to 17, other to 19. The wire to the plugs goes from 17 to the first plug & there is a bar from the first to the second plug. Hopefully that's the correct wiring.

Thanks,
Mike


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Dave_eng

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Equipment
M7040, Nuffield 465
Oct 6, 2012
5,107
926
113
Williamstown Ontario Canada
The GP wiring can be complicated particularly around the key switch.

The best explanation and current flow paths are in the B7100HST WSM.



This is one of the illustrations from that manual.


Battery power comes into the switch on terminal 30.
With the switch in the GP heating position, current flows from terminal 30 to terminal 19. On terminal 19 is one end of the GP indicator.

Terminal 17 serves only as a junction point. The second end of the GP indicator connects to terminal 17 . The main power supply to the GP's also connects to terminal 17.

The effect of this wiring is to have the GP indicator in series with the GP's themselves. If the GP indicator is not glowing, then there is no current flowing through one or more glow plugs to ground.

It is possible for some older tractor to have a different wiring schematic. Unfortunately, the WSM's and wiring diagrams for these are hard to impossible to find and are often copied so many times becoming illegible. I found again and reviewed the L260 GP info. They are wired in parallel like the B7100

So the answer to your question: bad glow plugs will keep the indicator from glowing.

The GP's are generally not too expensive.

Ask more if this does not make sense.

Dave
 

McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
Thanks Dave! Looks like I have it wired correctly now, just need new plugs. So far no one has them in stock so I'll post back later this week how it works out.

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McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
The new plugs finally got here today. I put them in & she starts like a dream now! The indicator hadn't even started getting yet. That thing takes forever to glow.
Thanks again everyone!

Mike

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Jpatrick

Member

Equipment
BX1850, L210, Various 3 point implements
Apr 4, 2017
100
1
18
Buckingham, Pa
The glow plug indicator on my L210 takes a full 30 sec to glow red. When it's less than 50 F outside, it needs to stay red for another 30 sec and sometimes more. In colder weather, sometimes it's necessary to get the engine to fire, and then flip the glow plug switch back on while the engine starts up.

It's smoky and unsophisticated, but it works.
 

McRoth

Member

Equipment
L260
May 22, 2018
32
5
8
Grafton, Ohio
Have you adjusted the valves? I adjusted mine this summer soon after I got it because I was having a hard time starting, glow plugs weren't working then either. After adjusting it started much easier.

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timsch

Member

Equipment
'49 8N, L275DT
Jun 11, 2018
100
20
18
Houston, TX
Just to add for future reference:

My GPs and indicator were getting no power. The 1st thing I did was to take off the GP wire connections. I checked the GP resistance and it was good. The wires and washers on the GPs were pretty corroded. Once I cleaned/ground them back to good metal and reassembled, everything worked again.

Easy fix.
 

D2Cat

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L305DT, B7100HST, TG1860, TG1860D, L4240
Mar 27, 2014
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40 miles south of Kansas City
McRoth, try leaving the power to the GP's on longer, like 30-40 seconds. Look at your watch, because 30 seconds seems like a day when you're setting there waiting!!