55.2-59 How to remove the lighting switch?

[BlouDon]

I'm trying to get EVERYTHING working on my truck.

I even got the horn working having had to fabricate a spring loaded rod that would make and maintain contact with the horn button and the slider ring.

Today I looked into the interior light. I read the manual and found that one had to turn the lighting button all the way anti-clockwise, to the stop, and then through it. That happens but no interior light. Instrument lighting also very flaky.

The feel and sounds from the lighting switch makes it clear that it is in need of TLC (or replacement).

How does one remove it?

[mongocanfly]

when you pull out on the light switch knob, theres a button on the backside you have to press to get the switch knob out of the switch...theres a how to on utube
and this ... http://67-72chevytrucks.com/vboard/s...d.php?t=571296

[BlouDon]

Originally Posted by mongocanfly

when you pull out on the light switch knob, theres a button on the backside you have to press to get the switch knob out of the switch...theres a how to on utube
and this ... http://67-72chevytrucks.com/vboard/s...d.php?t=571296

Thank you! The video was most useful. I was able to get the shaft out but the fastening nut won't budge, not even with my impact driver.

I squirted copious amounts of penetrating oil into the shaft hole from the back all the way to the front and everything now works better but the interior light still won't come on.

I did note that there should already be 12V on one of the two terminals at the bulb. I'll test for that next.

[BlouDon]

Interior light is working! Amazing how something so mundane can be so rewarding....

12V was present at the bulb fitting. The problem was the earth being provided by the switch. It simply was not making contact to earth. Highly repetitive switching the interior light on and off eventually allowed current to flow and the light came on reliably.

[1project2many]

Interior light is working! Amazing how something so mundane can be so rewarding...

Agreed. Despite the larger rewards available, sometimes a simple victory carries the greatest value.

Highly repetitive switching the interior light on and off eventually allowed current to flow and the light came on reliably.

I suggest determining where the corrosion exists and repairing it. Without cleaning you risk the light not working at some time in the future.

[BlouDon]

Originally Posted by 1project2many

I suggest determining where the corrosion exists and repairing it. Without cleaning you risk the light not working at some time in the future.

Good advice, and I agree, but I can not get the switch out. Cant get the mounting nut loose. I'm treating it with penetrating oil front and rear and will try again next weekend.

[mr48chev]

It rather depends on if you plan to reuse it or not even if you don't use it on that truck. you can take more drastic measures if you don't intend to save it. It may just be a case of dissimilar metals corroding against each other.

[dsraven]

the switch is held in with the nut that screws into the switch. penetrating oil on the nut from the front side of the dash may or may not get into the threads on the switch. if you can get to the back side of the switch with some penetrating oil and give that a try you might have better luck. if replacing the switch and the nut is an option you could simply drill the nut from the front side of the dash until it lets go then the switch will fall off from the back side. at that point you could clean up the corrosion on the back side of the dash and/or switch and then see if the switch is salvageable, whether you are then able to get the rest of the nut out of it and the switch is usable, or just replace both items. not sure on how available those items may be in your neck of the woods. the nut is likely something common to a lot of older style vehicles as far as size and thread are concerned. looks and thickness of the flange may differ. I know that style of switch is common to different manufacturers even into the '80's.
the switch needs to have a ground to the dash and the dash needs to have a ground to the cab, the cab needs to have a ground to the frame, then the frame needs to have a ground to the battery negative as well. sometimes the body ground is corroded or fell off at some point so that could be something to investigate as well, since you were also having gauge problems. the ground is a common item to all the cluster lights, gauges, heater motor, interior light, radio, cig lighter etc

[BlouDon]

Originally Posted by dsraven

the switch needs to have a ground to the dash and the dash needs to have a ground to the cab, the cab needs to have a ground to the frame, then the frame needs to have a ground to the battery negative as well. sometimes the body ground is corroded or fell off at some point so that could be something to investigate as well,

Good points, thank you! I'll investigate. All my gauges are working perfectly now, but good earths won't hurt.

[BlouDon]

Originally Posted by dsraven

the switch needs to have a ground to the dash

Battery is grounded directly to the cab. From the cab, braided ribbon to the starter.

Could not find a dedicated ground for chassis.

[dsraven]

so, how is the battery grounded to the engine? just a little braided cable? it should be a regular sized battery cable to the engine, a smaller, possibly braided cable to the cab for all the cab electrical, another to the frame for stuff grounded to the frame like tail lights, another from frame to rad support to ground headlights. anything that is electrical needs to have a ground somewhere.

[BlouDon]

Originally Posted by dsraven

so, how is the battery grounded to the engine?

From battery to cab (immediately behind the battery) and then from the cab to the engine via braided cable (about 1" x 1/8"). The whole truck is so original, I rather doubt that all this is not correct.

Originally Posted by dsraven

it should be a regular sized battery cable to the engine, a smaller, possibly braided cable to the cab for all the cab electrical, another to the frame for stuff grounded to the frame like tail lights, another from frame to rad support to ground headlights. anything that is electrical needs to have a ground somewhere.

I'm with you. It would have made so much more sense to run both cables to the starter and then from there to the cab and chassis. On my C10 I installed rather thick (welding) cables directly from battery to starter (12V and GND), and then I installed thinner (but still at least 1/4"conductor) from battery to chassis.

[dsraven]

Maybe a pic of your battery area would be good to see. Otherwise, from the perspective of a totally stock truck, you could find that in the assembly manual I posted a link for back a few posts. Since the starter is the biggest draw you have at several hundred apps, there is usually a stout cable directly to the engine, sometimes connecting to the frame enroute to the engine. Then smaller cables from there to ground things like cab or rad support etc.

[dsraven]

looks like assembly manual has the ground going to the cab directly behind the battery and another strap from frame to engine. didn't have time to finish checking it out but there must also be a strap from cab to engine or cab to frame in order to connect the battery to the engine with a good sized cable of some sort, like what is connected to the battery. check it out in assembly manual section 12. ensure all those cables are in good shape and the connections to each part are also good. voltage drop through each connection could add up and make lights dim, gauges act up etc.

https://www.trifive.com/55-59Assy.pdf

[BlouDon]

If things look odd.... This is a RHD.

[dsraven]

looks like you have it covered.
is the battery in front of the driver then? you're right, it looks odd to us leftys. haha.
sure looks to be in good shape. totally opposite of mine.
so, battery ground to cab, cab ground to engine, makes starter whirr like it should. is there also a frame ground somewhere to connect the dots for all the lights etc?

[BlouDon]

Originally Posted by dsraven

is there also a frame ground somewhere to connect the dots for all the lights etc?

Have not seen it yet. Any idea where to look?

[dsraven]

For a stock location, no. You could easily make one yourself but if everything works there must be one somewhere. Peruse through section 12 I suppose.