farmall H lights

farmallboy15 · Jul 9, 2010

the lights on my H are not working what is the most likely cause i find it hard to beleive that all three lights are burned out and they don't look it. wiring? switch? field resistor? dimmer resistor?

Kevin in MI · Jul 9, 2010

Bad ground

farmallboy15 · Jul 9, 2010

where at do you think? isn't the only ground on the belt pulley? or are you talking the wire on the outside of the light?

Clarkbug · Jul 9, 2010

(quoted from post at 08:04:02 07/09/10) where at do you think? isn't the only ground on the belt pulley? or are you talking the wire on the outside of the light?

The lights themselves are grounded back to the frame. If where they clamp to the light bar or the deck has a think layer of paint/grease/etc. on it, they wont complete the ground, and wont work.

But also, dont rule out blown bulbs. If your machine was converted to 12v and the 6V bulbs werent replaced, that would have blown all three of them.

Nebraska Cowman · Jul 9, 2010

Where the bulb itself is in the socket. Dirt dirt and more dirt, cobwebs, moisture, paint, and rust. All are good insulators. The bulb needs an unbroken path to ground and an unbroken path to power. The key is "unbroken". Find your break (breaks) and the lights will work.

GordoSD · Jul 9, 2010

Remove the bulbs and test them on a ggod battery.

mkirsch · Jul 9, 2010

You're just going to have to go through them systematically. Take them apart, test the bulbs, clean them up, clean up the ground points, replace the wiring. On a letter series tractor, rewiring the lights is not a huge deal.

There just isn't one definitive cause or one definitive place to look. Lights can be some of the most frustrating things to troubleshoot and fix, but the only way to do it is the "hard way."

Theman · Jul 9, 2010

If you have the newer box, it could be as simple as a blown fuse. If you see a small knob between the ammeter and light switch, it is a fuse holder. My '47 doesn't have one, but my '51 does. I'm not sure when IH added this feature, but it protected only the light circuit.

pete 23 · Jul 9, 2010

Older H had fuse also but it is inside on back of light switch. Only way to get good reliable lights with these rusted out old lights is to provide a good clean ground. I do it one of two ways. I solder a wire to the light bulb socket itself and run that wire to ground or I again solder the a short wire between the light bulb socket and the lamp housing itself inside, then clean all the mounting spacers and bolts and clamps and light bar, maybe even steering post itself.

sflem849 · Jul 9, 2010

I subscribe to most, if not all, of the methods above. I also like to use WD-40 in most of the situations. It cleans and displaces water very well. It is a terrible penetrating oil (compared to more recent penetrants) but it still does this job very well.
A good test light or MM is your friend as well. I would start at the power source and work my way out. You could swing for the fences on the first try, but I would guess there are a few problems before the lights. On my SMTA I had a bad bulb, a dirty switch, and a bad fuse holder.

farmall H lights

farmallboy15

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Kevin in MI

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farmallboy15

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Clarkbug

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Nebraska Cowman

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GordoSD

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mkirsch

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Theman

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pete 23

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sflem849

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