No lights, fuse visually checks out.

[greg g]

So today we did a tour run with 6 other cars.  When it started getting dark I pulled on the parking lights, running them with my fog lamps.  When it got darker about 15 minutes till sunset, I pulled on the headlamps.  As it got darker, noticed no instrument lights,  no high beam indicater.  Checked the fuse in the light switch and it looks good.  Cleaned the contacts, reinsert and nothing.

 

Had a guy under the dash, installing a new speedo cable.  Wonder if he tugged some wires while doing what he did.  No time or energy to check tonight.  Tomorrow guess, I will be under the dash looking around with jumper wire and circuit probe.  If I recall the switch gets power from the Amp gauge direct to the switch.  If I power from the battery with a jumper wire can I bypass the fuse to power the switch to do my checks for power in and power out?

 

Also is there supposed to be a spring in the fuse holder.

[ptwothree]

Dimmer switch contacts crudded up? 

[Worden18]

I just put a new speedometer cable in my truck, and I'll tell you this, I was bumping into wires all over the place. I wonder if he did loosen something up. I would check that first before even getting out any jumper wires or test lights.  a wire gets pulled and things loosen pretty quickly.  I also recently had a failed heater fan switch in my truck, which turned out to be a loose connection.

[greg g]

Don't think the dimmer switch being corroded would effect the dash lights and tail and tag lamps.

[desoto1939]

High beam indicator light works off the dimmer switch.  Hit the dimmer switch several time to reclean the contacts.  This switch gets all the road crud since it is located under the floor boards. 

 

Also pull your light switch off and on several times the contacts also get crud from sitting and need tobe cleaned just by pulling and cleaning up the contacts.  It sould also just be the switch is bad.

 

Rich Hartung

[greg g]

Went through that routine before checking the fuse. Cycled all the switches a dozen times or so. Going to start the trouble shooting by assuring there is continuity through the fuse, that the fuse is properly inserted and that there is power to the switch.

[greg g]

Went through both shop manual and parts book.  Neither shoe the switch in any detail, nor does the wiring diagram.  Any body have a switch laying about you could post pictures of?  Is there supposed to be a spring in the fuse holder, or is there something within to provide some pressure to keep the fuse tight to its connection.  This one seems l[se, though no spring fell out with the fuse.  This one has the brass end fitting that twists a quarter turn or so to release and or insert.

[Young Ed]

From what I recall there is no spring. The fuse contact on the switch end acts as the spring. 

[greg g]

Well, I shade treed it.  After confirming the fuse and retainer for continuity,  a rolled up a piece of aluminum foil inserted to take up the slop in the holder.

 

The Prince of darkness vanquished once again, let there be light!

 

And so there was upon the Plymouth incandescence front and rear.  And the people were relieved and proclaimed their relief.

 

Now we light a candle to stave off electrolytic galvanic corrosion from contact among dissimilar metals.  

 

Is this alchemy?  Might I find a chunk of gold where it was once a wad of Reynold`s finest?  Should I remove the foil and insert a piece of solder?

Edited October 15, 2021 by greg g

[desoto1939]

sounds as if the fuse length was not long enough to make a full contact. My  fuse is inthe light switch and is held in by a metal plugs that has tabs onthe ends and then you push up the holder to make a tight fit.

 

Try a 20 amp fuse but a longer fuse.

 

Rich Hartung

[oldodge41]

I wonder if the guy doing the speedo cable shorted something? Saw a spark, blew the fuse and replaced it with the wrong one. The new one being too short.

[9 foot box]

   The correct fuse is 1.437” long. NAPA 782-1076 is what I bought, SFE-30. Rick D.

[keithb7]

What year car are we discussing here? I saw an ask for pictures of a light switch. 
 

I gutted a spare one that I own. Cleaned it internally. Sealed it and Stored it for future use. I’m talking mid-late 30’s light switch. 
 

Here’s another one in my other car. It Was falling apart. I Replaced wires. I disassembled and cleaned it up. Works good as new!
 

 

Edited October 16, 2021 by keithb7

[greg g]

Sorry,  it's a 46 P15.  The fuse is a 30 Amp. It is labeled as a cgh or similar but not 30 Amp sae.  I can't remember if I had needed the headlights this s eason before Thurs.  I can't see at night so dont plan on driving needing the lights..  Although I do recall checking them prior to the p15 picnic trek.. last month. But we went longer than expected on our tour and got caught out at dusk.  Luckily I have good fog lamps and my brake lights and signals aren't wired through the switch.  Had a friend on my six for the last 20 miles.