434D - Electrical and Lights Question

I've been beating my head against the wall with electricals on my 434. Not a single light or indicator works on this tractor (but the glow plugs glow and it starts fairly well).

I have the I&T shop manual (the only one I could find) but it's not terribly helpful... All of the key electrical diagram entries are missing the information in the legend.

1. I need to figure out how the front wiring to the headlights needs to look, so I can figure out if they work or need to be fixed/replaced.

2. I need to understand the 4 or 5 position light switch - what does each position light (headlights, plough lights, rear work lights, dash illumination, loader work lights, lighthouse on the north shore?)

The story so far:

The 2 headlights seem to be intact, but none of the others. So I thought I'd save myself some agony and picked up a pair of 12v 3x5 rear work lights. I connected one to the right-hand rear light harness (through the wreckage of the old light housing). I got exactly 1 brief flash of light and no more.

I connected the multimeter and I got various measurements (at various switch settings) of 1V all the way up to 8V and ever so briefly 11V. None of them constant at any switch setting, BTW.

I got the same on the other side. I thought perhaps the halogens are too demanding for precise voltage, so I swapped them for a pair of generic 12V sealed beam lamps. I couldn't even get them to light up once.

The only other curious item (and it relates to headlights) is that the wiring harness is broken at a grounding point on the front of the frame. I can see the bolt, the spade connector and 1/16th of an inch of black wire. There are also a pair of thicker (12GA?) black wires with no obvious home. Normally I'd think it was straight forward, except half of the wires in this tractor are black (painted). The other half have been painted red...

Just in case, I ran another small gauge wire from that bolt to the pair of black wires. No real difference in multimeter readings.

Is this normal?
Is it a wiring problem? A voltage regulator problem? A fuse problem? or a user/operator problem?

Any one with answers, a 434 user's manual or amused sympathy please reply.

Cheers,
Andrew

Currently completely rewiring a 364Dsl. The wiring was a unreal mess. Not a single light or gauge was working.Ended up removing 90% of the wiring and starting over.It was quicker to rerwire that to fix existing wiring.

My advise is to break the wiring down into simple single circuits( front lights/rear lights/flashers/temp gauge/etc) and check each connection/part of that circuit till you get it working and then move on the next circuit. I found broken wires, corroded connectors, rewiring done wrong, fuses with high resistance and especially difficult to find bad grounds. Also watch out for bare spots where insulation has melted.

Just because you have a wire between two connections you can not assume you have a good connection. Also just because a wire is connected to a grounding screw or nut it may not be making contact due to corrosion or paint.

good luck/ hope this helps
brmtdg

It seems I'm not the only one with this problem - sort of good to hear.

Do you have any idea what the positions on the light switch should be? Like which lights should light up at each position?

If I could figure that out, I could probably start the rewiring.

Thanks again,
Andrew

Send me an email at clarabrownlee@rogers.com and I will scan and email you the wiring diagram.

Happy Thanksgiving
JimB