4WD Light Not Turning ON or OFF

Diffs, axles, lockers, transmissions, portals, that kind of thing.
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Pinzi73
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Location: Worcester, Massachusetts

4WD Light Not Turning ON or OFF

Post by Pinzi73 »

Looking for a little bit of troubleshooting help. Over the summer I started having issues with the 4WD indicator light. First off, let me start by saying that "as far as I can tell, the 4wd system is engaging and disengaging properly". Now on to my issue. I took the truck to the beach and engaged the 4wd system. The light came on as expected. How ever, when I disengaged 4wd, the light sort of went out but would stayed on very dimly. The next day the light would be out. I figure it was a sticky switch. I checked to make sure the 4wd system was disengaged, which it was.

So, for the rest of the season I drove it this way. A week ago when I engaged 4wd, the light would not come on. The 4wd system engaged properly. My question is this. Where is the switch or unit providing the output to the indicator light. I already checked the bulb. Should I be looking at something else?

Thanks
1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
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berger
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Re: 4WD Light Not Turning ON or OFF

Post by berger »

The suggestions in this post may help.

http://www.real4x4forums.com/PinzgauerB ... r+light+on
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1974 710M
2007 2WD Ural Patrol
undysworld
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Re: 4WD Light Not Turning ON or OFF

Post by undysworld »

The switch is mounted on the drivers side, just opposite the hydraulic line going to the locker on the central tube, just ahead of the transfer case, under a little cover.

Remove cover, ground single wire. If light works, then you have a bad switch. If not, then check for 24 v at lamp, bad lamp, or wiring issues.
Buzz
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Re: 4WD Light Not Turning ON or OFF

Post by Buzz »

I would add that in addition to checking the electrical parts per the other posts, that you take a look at the rubber elbows that connect the levers/valves to the fluid reservoirs. I had had those split and leak enough to do what you are describing. Lastly, I would bleed the fwd and locker lines. I know that I tend to forget about those lines when I do the brakes etc. and they can absorb water just like anything else. - Buzz
"It's as stupid and wonderful as owning a pet elephant."
1974 Pinzgauer 710M
1990 Puch G Wagon 230 GE
mopar
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Re: 4WD Light Not Turning ON or OFF

Post by mopar »

Steve
Try flushing out the hydraulic lockers dot 3 brake fluid and is pretty simple they get some waxy build up in the lines that makes its way down to the slaves at the axles. You could check the switches and try some cleaning at the contacts as I think the switches ground the lights to come on and maybe some corrosion from water and mud as I know you've wheeling.

1974 712M AKA the Banana
1974 710M AKA the project truck
1987 718M Now Sold
1975 Volvo TGB1111 Now Sold
1973 Pinzgauer 712M x2 Now Sold
1963 404S Now Sold
Pinzi73
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Joined: Tue Jul 30, 2013 5:13 am
Location: Worcester, Massachusetts

Re: 4WD Light Not Turning ON or OFF

Post by Pinzi73 »

Thanks all! I will work on it this weekend. I'll post up with my success or failure in fixing it.
1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
Pinzi73
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Location: Worcester, Massachusetts

Re: 4WD Light Not Turning ON or OFF

Post by Pinzi73 »

Ok. I'm back at this. Can some point me to a drawing or picture that shows were the damn switch is located on the truck that turns the light on. Bulbs are fine. I'm convinced its a stick or corroded switch. Just need to find it.


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1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
Pinzi73
Posts: 62
Joined: Tue Jul 30, 2013 5:13 am
Location: Worcester, Massachusetts

Re: 4WD Light Not Turning ON or OFF

Post by Pinzi73 »

Lines have been bled and fluid changed.


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1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
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Jimm391730
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Re: 4WD Light Not Turning ON or OFF

Post by Jimm391730 »

The switches that activates the locker lights are on the opposite side of the backbone tube from the slave cylinder that you bled. The switch should ground the wire to turn on the lights.
Jim M.
712W and 710M
Pinzi73
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Re: 4WD Light Not Turning ON or OFF

Post by Pinzi73 »

I can find the locker switches on the tube, just not sure where the one for the 4wd light is.


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1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
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pcolette
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Re: 4WD Light Not Turning ON or OFF

Post by pcolette »

The switch for the 4WD light is hidden behind the muffler (between the muffler and the center tube). It typically has an additional square sheet metal shield (#7) over it to protect it from the heat. If the bolts securing the muffler to the heat exchanger aren't too rusted, it's much easier to remove the muffler to gain better access to the switch.
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Paul C.
_________
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Pinzi73
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Re: 4WD Light Not Turning ON or OFF

Post by Pinzi73 »

Thank you !!


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1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
Pinzi73
Posts: 62
Joined: Tue Jul 30, 2013 5:13 am
Location: Worcester, Massachusetts

4WD Light Not Turning ON or OFF

Post by Pinzi73 »

I just want to clarify. The switch for the 4wd light is located just past the center tube beside the muffler. I opened that up cleaned all the connections and removed the switch to make sure it still moved. Still no light. What mechanism actually pushes the switch? I wonder if that is gummed up.


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1973 Pinzgauer 712M

It's like being a celebrity driving this puppy around town. You can't go anywhere without someone stopping you or coming up to you to talk about it. ;-)
mopar
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Re: 4WD Light Not Turning ON or OFF

Post by mopar »

Steve
Follow the wiring to the switch if I remember correctly I believe there is a factory(in a clear plastic) bullet connection enroute to the switch. I think when I first got the truck the light didn't work but I verified the 4wd was working and didn't really worry about it. When I was wiring my leds and reverse lights I found that wire and and the connection. I simply plugged it back in and voila the light worked and was good to go. I believe it is a single wire that just grounds out to complete the light circuit so it is not really a light switch per se. I bet you it just worked itself loose. The easiest way would be to trace the wire back from the switch to the engine its no more than a foot or 2 from the actual switch. Sorry I didn't remember this earlier but it just popped into my head when looking at your description of the switch. It will be a duh!! moment if and when you find that to be the problem and it is solved that easy. Hope that is it and this helps you solve it quickly. If your around I could always try and stop by some time and take a quick look and probably find it quickly for you since I've seen it once before.

1974 712M AKA the Banana
1974 710M AKA the project truck
1987 718M Now Sold
1975 Volvo TGB1111 Now Sold
1973 Pinzgauer 712M x2 Now Sold
1963 404S Now Sold
undysworld
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Re: 4WD Light Not Turning ON or OFF

Post by undysworld »

Pinzi73 wrote:I just want to clarify. The switch for the 4wd light is located just past the center tube beside the muffler. I opened that up cleaned all the connections and removed the switch to make sure it still moved. Still no light. What mechanism actually pushes the switch? I wonder if that is gummed up.


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24v is supplied to the lamp, and then the ground is made through (and by) the switch.

Take the single wire that attaches to the switch, and ground it. Now check to see if the indicator lamp is lit. It should be.

If not, check for 24 v supply at the lamp on one terminal. You should find it there.

Maybe the switch is bad, so not passing electricity when it's depressed, and that could be checked with an ohmmeter.

If you've got power at the lamp, and the lamp is good, and the switch is making a ground, then it's probably the connecting wire which Mopar described.

The switch is depressed after the locker engages, not right when the lever is depressed. The lamp shows actual engagement of the locker. If you are truly in 4wd, then I'm pretty sure the mechanism which depresses the switch is working correctly too.
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