GC2410 Rear Light Weirdness

[mgstevens]

I have a situation where the left side rear light unit has gone troppo. All bulbs work (ie: not burned out..) but when I turn on the headlights, I get one of the signal indicators (left) lit up on the dash, and the red light for that side is out, but flashes when I turn on the turn signal. The yellow part is not lit under any conditions (signal or flashers).

I went after this problem the other day and while disconnecting and reconnecting the harness connectors at the rear of the machine, the entire unit began working as it should. Then today, I sorted out the bad ground on a couple of worklights mounted to the protector rings and the left-side-malfunction-state returned.

The wiring for the worklights and the taillights are in no way intermingled. Totally separate wiring from fuse box back.

Any ideas how to begin tracking down the issue? When it began working properly the other day, I have no idea what I did to make it work, I was just opening a couple of connectors. Today, I cleaned those connectors with some CRC electronic cleaner, to no avail.

:confused3:

 

[ray66v]

If it's not a connector, or damaged wiring that only leaves a bad ground, or an internal short in the bulb.

Sometimes one filament in a double filament bulb breaks and makes contact with the secondary filament. It can then illuminate giving the impression it is working, when it is actually shorting. This problem can be interment as well. One way to test for this, is to remove the bulb and while looking at the filaments, flick it with your finger watching for movement inside. a broken one will vibrate. Or, just try another bulb if you have one handy.

 

[mgstevens]

The bulbs have proven themselves by working properly a few days ago, but I will check them as you suggested.

After seeing that the entire left-hand light assy works as intended when a clean circuit-state is achieved, I recall that after testing the left-hand connector for voltage, I lost headlights completely. I must have shorted a circuit as the fuse was blown. After replacement, the entire tail light/signal/hazard system worked. Then I worked on the work lights, which entailed chasing the circuit for continuity until finding a bad ground. Fixed the ground, reinstalled the fuse tap for the hot side and everything worked fine. Alas, the tail light/signal/hazard issue was back.

I will also check the appropriate fuse again, and test again for voltage and continuity in the tail light/signal/hazard circuit. The schematic shows a relay in the circuit, but I haven't located that physically yet.

 

[WranglerX]

The bulbs have proven themselves by working properly a few days ago, but I will check them as you suggested.

After seeing that the entire left-hand light assy works as intended when a clean circuit-state is achieved, I recall that after testing the left-hand connector for voltage, I lost headlights completely. I must have shorted a circuit as the fuse was blown. After replacement, the entire tail light/signal/hazard system worked. Then I worked on the work lights, which entailed chasing the circuit for continuity until finding a bad ground. Fixed the ground, reinstalled the fuse tap for the hot side and everything worked fine. Alas, the tail light/signal/hazard issue was back.

I will also check the appropriate fuse again, and test again for voltage and continuity in the tail light/signal/hazard circuit. The schematic shows a relay in the circuit, but I haven't located that physically yet.

Generally when lights go bizarre it is usually bad grounds.... If you are experiencing corrosion in bulb sockets or connectors, clean them well and apply some dielectric grease to contact points, it keeps moisture and oxygen away from the contacts therefore prevents corrosion....

IF your 2410 is similar to my 1715 the relays are of right side of console on upright between dash and frame... Probably going to have to remove the panel below dash to get to them....


(GC 1705 to 1720)

Dale

 

[mgstevens]

Thanks for the relay locale, I will check. Also, if not in the supplies already, I will add dielectric grease to the kit, and the contacts.

When I was originally testing the bulb sockets, I was not getting 12V on the left side, I moved to the next connector and also did not get 12V - although I was getting it on the right side. Then lights out, then change fuse, then all work again. I will see if I can get continuity in all branches of that left-side circuit.

Thank goodness for schematics.

PS: What document are you getting this Section 7.1.2 page from?

 

[WranglerX]

Thanks for the relay locale, I will check. Also, if not in the supplies already, I will add dielectric grease to the kit, and the contacts.

When I was originally testing the bulb sockets, I was not getting 12V on the left side, I moved to the next connector and also did not get 12V - although I was getting it on the right side. Then lights out, then change fuse, then all work again. I will see if I can get continuity in all branches of that left-side circuit.

Thank goodness for schematics.

PS: What document are you getting this Section 7.1.2 page from?

Service Manual for MF GC 1705 to 1720.... #42383491M1...

Dale

 

[lpakiz]

I like these electrical problems! In my experience working on semis, with these unexplained cross bleeding lights, it is almost always a bad ground.
One of the most basic ways to prove that out is as follows:
Find a good ground location. The best one is the negative battery post. Otherwise, the tractor frame itself might suffice. Clamp a vise grip on the selected ground location. Wiggle it around to scratch thru the rust and paint, or grind or scrape a bare spot somewhere. Then use a jumper cable from there to a small screwdriver or sharp awl.
Take the lense off the offending light and touch the brass base of the bulb with the probe of the new ground system. Most times, everything works properly. Remove the probe and the problem usually returns.
So now we have determined that there is a bad ground, but how to find it? Keep probing different components, wires, frames and see if you can correct the problem. Keep going downstream towards the ground post of the battery.
Do not trust a connection that looks good and/or clean. Remove it, wire brush it or grind it bare, then reattach.
On heavy draw situations, a poor ground will generate heat. I have loaded a poor connection solely to make heat, then go along and feel the different connections. None should be warm.
There are ways to do this with a digital ohm meter, but that will be for another day.

 

[cdaigle430]

Dont rule out a dirty or corroded switch at the dash panel especially if its intermittent.

 

[lpakiz]

Yes, for sure. Switches can cause headaches,.
But if you are experiencing odd performance, like the semi trailer clearance lights blinking when a turn signal is activated, that is more likely poor ground rather than poor supply. One would think that these two functions would have nothing in common, but they do, in fact, have a common link. That link is the return path (ground) back to the power source. That is where they are related.
Keep in mind that the supply path is exactly one half of a circuit. The other half is getting those used electrons (every one of them!) back to where they came from.

 

[WranglerX]

Want some real fun?... Try shooting grounding problems on fiberglass bodied (kit) cars.... Specially after 2 or 3 know nothing have worked on it before it comes to you....

Dale