1947 Farmall M front lights not working.

Jmuller · Apr 5, 2016

I had my 1947 Farmall M restored and the lights on the light bar don't seem to work consistently. The rear light works without fail. When the tractor was restored the wiring was switched to 12 volt.

The quick research that I did was that the two U bolts that hold up the light bar assembly are actually used as a ground. When I loosen the bolts and jiggle it around the lights will light up. Do I need to clean off the area where the new paint is where the U bolts touch and then tighten back down or is there a different solution?

Thanks for your input. JM

P I Pete · Apr 6, 2016

You got the right idea the light bar needs to have a good clean contact with steering post and the steering post to frame of tractor and each light needs a clean contact with light bar to complete circuit. Pete

Steve@Advance · Apr 6, 2016

Bad grounds are very elusive and cause strange things to happen. They can show up in the strangest of places!

Good grounding does require getting down to bare metal, something I hate to do to a nice paint job. Another solution is to run a ground wire from the light base back to a known good ground, like the transmission case or engine block. Just don't put the ground wire eye under a critical bolt that can leak or vibrate loose.

Jmuller · Apr 9, 2016

I sanded down to the bare metal on the light post for the U bolts to have a good contact to bare metal and the front lights work again!! Hard to
sand down good paint from the restoration but the bolts covered it up and what was showing I was able to touch up. Thanks for the replies on
confirming what I needed to do. JM

1947 Farmall M front lights not working.

Jmuller

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