TN85FA Wierdness

[Brans]

This is a New Holland with under 900 hours on it. When the turn signal switch is moved to either left or right, both of the front indicators blink slowly and dim, nothing at rear. If the flasher switch is pressed the same thing occurs. when the light switch is turned to the first position, the rear running lights come on dimly, the second position makes the headlights work with no change at the rear.Both beam settings and high dip switch seem to work fine. **The rear work light doesn't do anything unless the key is on. Activate the flashers, with the key on, flick on the rear work light, the rear turn bulbs, along with the work light itself will all pulse in time with the front indicators, very dim. **With the key off, but the light switch on, with the rear work light switch on, the #1 relay clicks in time with the front indicators, as does the fuel pump shut-off relay... Havn't bothered to verify what the # 1 relay is for, the layout does not exactly match any version options in the owners manual I have to look at/ Thank you New Holland... This is a 4x4 manual transmission model,no shuttle, no cab, no front lift, a fairly straight forward model as these things go.
I verified good ground to all four corners.I checked the ground under the console, and at the rear left. have checked the wiring harness. have tried another flasher unit. have unplugged the multi-function switch. Have wasted half a day...
Help?

 

[boggen]

breaking your post up. to make it easier to read.

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This is a New Holland with under 900 hours on it.

When the turn signal switch is moved to either left or right, both of the front indicators blink slowly and dim, nothing at rear.

If the flasher switch is pressed the same thing occurs.

when the light switch is turned to the first position, the rear running lights come on dimly,

the second position makes the headlights work with no change at the rear.

Both beam settings and high dip switch seem to work fine.

**The rear work light doesn't do anything unless the key is on. Activate the flashers, with the key on, flick on the rear work light, the rear turn bulbs, along with the work light itself will all pulse in time with the front indicators, very dim. **

With the key off, but the light switch on, with the rear work light switch on, the #1 relay clicks in time with the front indicators, as does the fuel pump shut-off relay...

Havn't bothered to verify what the # 1 relay is for, the layout does not exactly match any version options in the owners manual I have to look at/ Thank you New Holland...

This is a 4x4 manual transmission model,no shuttle, no cab, no front lift, a fairly straight forward model as these things go.

I verified good ground to all four corners.I checked the ground under the console, and at the rear left. have checked the wiring harness. have tried another flasher unit. have unplugged the multi-function switch. Have wasted half a day...
Help?

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go to below web page

New Holland USA - Tractors - Agricultural machinery - Combines, etc.

then move mouse over ""parts and services"" then click ""search for parts""

once page loads up. type in model number. and click plus sign beside "electrical"

it is not the best wire diagrams in the word. but might help ya.

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not a gear head by no means, and someone else be better taking info from. but it almost sounds like you have a couple wires short circuiting. and i am wondering if one of your harness connections might have came loose and have some water in it? or perhaps a harness cable is been jammed up some place, and is getting short circuited.

maybe a mouse or other pest built a nest some place and nicked some wires over winter?

i did see a diagnostic plug in, when looking over new holland website. not sure if you could take to dealer and have them test things out. or if that is primarily just for engine testing vs lights.

not sure if it would be worth while or not, but try pulling fuses for lights, one at a time and testing all the lights, example: what happens, to rear lights (stop, single, tails, and rear work light) when you say pull fuse/fuses for front work lights, singles, flashers)?

for left and right turn singles. is it possible to disconnect the switch from wires. and use a small jumper cable? (short piece of wire) and test the turn singles?

 

[RickB]

You likely have a grounding problem in the lghting circuit, or the turn/flasher circuit. The diagnostic plug will help with transmission issues, not lighting.

 

[Brans]

Ya, it was a ground problem. What I hadn't noticed before was the ground tail

at the battery ground cable underneath the tray on top of the transmission.

Cleaned that up, used a new washer on top, coated it with ignition sealer, good

to go!

-Brans