No lights, lost manual, and now insane owner

[Farmwithjunk]

Got a problem. The bright lights on the right fender of my Massey Ferguson 150 went out last night while feeding cows. Not a problem! Or so I THOUGHT.

I THOUGHT it would be a simple "get out the meter and trace the problem" issue. No such luck. I tried everything I know to jump wires around the factory wiring to power up the lights. Nothing works. The dim lights (one of the two headlights on each fender) work. When I go to bright, they both go off.

OK, get out the shop manual. Let's see? Where did I put it when we moved? It's not with the rest of my manuals..... OH YEAH... Now I remember, I loaned it to my cousin, who's now in Japan on vacation.

Long story short, I'm obsessing over these lights. They GOTTA be working. Does anyone have a shop manual for the 135/150 that they could copy the wiring schematic and fax me a copy? If so PM me and I'll get you a fax #.

Anyone have a clue what I'm dealing with here? (My personal opinion is GREMLINS) (Yes, the bulbs all light when swapped to the other fender.) I suspect a ground problem, but so far can't find it. This is a relatively simple wiring harness, so it CAN'T be too difficult. (Famous last words)

Thanks,
In the dark.

 

[Nasty135]

I'm with you ,sounds like a bad ground to me, in the phone business we would call something that works like that a leaky circuit. It works somewhat until you put a load on it, Then the ground isn't sufficient to pass all the current/thus shunting it.

Set volt ohm to hi resistance setting and check all connections
,check through switch ,chassis ground ,lamp ground,you will find it. I would disconnect battery for true readings just so I don't get false indications across terminals. Meter should peg for a solid ground short if it doesn't there is too much resistance...sometimes broken/fraid wires at terminals may look ok but aren't good enough to pass current... If you already know this forgive me for being so yacky /forums/images/graemlins/crazy.gif just trying to help...

Also if you haven't gotten any further or better help, I have a manual for the 135 at home if need be. /forums/images/graemlins/cool.gif
Let me know and I'll try to help you out later this evening...

Edit: Are these bulbs in a socket or do the bulbs have prongs for a plug? If a socket , the sockets probably the culprit..look inside the socket for corrosion or contact with ground.

 

[Farmwithjunk]

My extent of electrical knowledge is this;

1. OFF
2. ON

From that point on, anything you can tell me is more than I already know.

I got the friendly local AGCO (MF) dealer to fax me a copy of the wiring diagram this morning. It's more or less what I already thought. No real revelations there.

The bulbs are screw lug to fork connections. Not too much chance of error there either.

I still think it's a ground problem. I have all new connectors to replace all of them on the fender. I'll do that tonight. I also remembered one thing I did yesterday that might just be the culprit. The mechanic at the MF dealer said he has seen more fender mounted light trouble because of a bad fender to axle ground than any single problem. Yesterday, I messing with the stabilizer bars. I always ran just one. I bent one a few days ago, so I decided to get new ones. (TWO this time. I never noticed with just one, but the left side bracket was too far forward. (Mounting holes are slotted) I got under the tractor and smacked it backwards with a 2 lb hammer. That MIGHT have disturbed the fender to axle ground connection. It was about 5 minutes later when I noticed the lights weren't working.

So, I guess I CAN'T fix EVERYTHING with a bigger hammer.