Pro Melt switch replacement question

[oldhenry]

My '79 (or '80) Pro melt has been trouble free until lately the switch failed. A call to CS @ RCBS had me a replacement in 3 days @ no cost.......thank you, RCBS.

I'm attaching images from different angles of the replacement switch attempting to show that the attachment system is simply 2 plastic clips on each end.

I would imagine that in 37-38 years the switch design has changed. If it was secured by hardware on the back side it would look to me that I could remove the old switch using the "Bubba" method (breaking old switch) & install replacement w/o removing the cover.

Has anyone changed out a switch recently that could give me some insight?

I'm capable of removing & replacing the cover if that is the only method.

Thanks,
Henry

[375RUGER]

If you dremel (yes, I realize I might be banned) off the portion of the flange where the clip is, you might be able to get a small screwdriver in to release the clips. Those style switches have been around for a looong time, so I suspect you will find the same thing.

[Walter Laich]

I replaced mine and had to open the housing. Just drilled out the pop rivets, replaced the switch and used pop rivet 'gun' to put it all back together.

[country gent]

If you can get to the back side a set of large pliers will compress the clips and allow it to be pushed up enough to remove it. Other wise I cut the clips of and remove it. Really if the switch is no good then why worry about saving its integretity.

[mold maker]

If you don't already have a pop rivet tool, this is a great excuse. You have to get to the back side of the sw to remove it. Careful not to damage the wire insulation.
Make sure to check the tension on the wire connectors.

[oldhenry]

If you don't already have a pop rivet tool, this is a great excuse. You have to get to the back side of the sw to remove it. Careful not to damage the wire insulation.
Make sure to check the tension on the wire connectors.

I have a pop rivet gun.

Do you think the attachment method was the same in '79 (or'80)?

[HATCH]

I would take a flat head screwdriver with a blade as wide as the switch.
slide it down from the top and push.
Pry out slightly.
You may need to take another small blade flat head and put it behind and see if you can push down the retaining piece.
Your switch is gonna prob be the exact same.
Only difference might be the material that its made of.

[oldhenry]

Hatch,
I'll give it a try tomorrow & take some photos.

If I fail, I'll drill out the rivets & also take photos.

Thanks for your input.
Henry

[Mal Paso]

#10x1/2" hex metal screws make a fine replacement for rivets. Mine had already been upgraded when I bought it.

[dikman]

Good idea, no law that says you have to replace pop rivets with pop rivets. As for the switch, I'd be surprised if it isn't the same as the old one.

[jsizemore]

#10x1/2" hex metal screws make a fine replacement for rivets. Mine had already been upgraded when I bought it.

Mines lived like this for the past 5 years. Holds the pot liner in place too. You never know when you may need to work on it again. If your concerned about the sharp point, a sidecutter will remedy that.

[oldhenry]

The removal of the switch was uneventful following the advise from HATCH. BTW a putty knife is the perfect tool. After freeing the switch from the sheet metal I met with resistance from the upper wire (it's shorter), but a little stretching got it out long enough to disconnect.

Upper wire: silver/grey color (I marked terminal with MM........even though it's shorter)
Center wire: also silver/grey
Bottom wire: white color

As installed the part #10203 was on the side facing left.

The upper & lower terminals had been bent away from the center terminal by RCBS. The old & new switches are identical: note photo (they show same part # & "CARLING").

I likewise bent the upper & lower terminals away from the center, installed the wires exactly as removed & pushed it into the opening & it seated easily.

PROBLEM: when I turned on the switch the light fixture over my work bench went out & wall outlets on either end of my work bench went out. I checked service box & nothing had tripped. All other electrical works OK.

I've drilled out all rivets & only have to remove the vertical through bolts to get the cover off.
I'm recovering from "the crud" & have had enough fun for today. I'll continue tomorrow & see it I can find the problem. I'm a little electrically challenged, but this thing can't be too complicated.

The saga continues tomorrow.

Henry

[Mal Paso]

You probably pulled the Hot end of the heating element into contact with the sheet metal.

Or if the switch is upside down, or they changed it ... the white wire is Neutral to power the light in the switch. The other 2 wires are Hot from the thermostat and Hot to the element. Wired wrong Hot could connect to Neutral turning the lights off.

I still am not completely clear of the crud myself.

[oldhenry]

Mal Paso,
Thanks for your insight, but I think I have located the source of the problem from the get-go.

I figured I wouldn't get much sleep tonight unless I went ahead & completed removal of the cover.

At the end of the main insulation of the power cord after it enters the sheet metal there was a suspicious looking lump that seemed to be vulcanized to the side of the wire leading to the thermostat. As it turns out this little oblong lump is the remaining carcass of some variety of insect (see photo). When I peeled this carcass away the individual insulation underneath looked weak (see photo).

I think this explains the switch failure (I'm often wrong).

I have a professional terminal crimper & possibly could repair, but I think I'll call RCBS tomorrow & order a power cord assembly (there are some unique ends & I'd feel better with a new cord......last photo)

Henry

[Walter Laich]

keep us posted.

I had my own open for the second time to bypass the temperature dial and now just use a PID for temp control.

If I refrain from adding sprues and such during my casting it will keep temp of pot to within 1°

[oldhenry]

Walter.
In order to keep you posted I must make a public confession: here goes.

In the cover removal process, it was necessary to remove the new switch (wires are not long) and it was then that I realized my mistake. Even though I had made written instructions to myself when I removed the damaged switch, I failed to follow my own instructions.

I had installed the switch upside down (part # on the right). I further realized that if that bug (looks like a type of millipede) had caught all of the voltage there wouldn't have been that much left of him. Also a close examination of the power cord reveals only accumulated crud @ the suspected failure point: I think insulation is OK.

I reinstalled switch according to my own instructions, riveted the sheet metal back on, replaced the breaker in the service panel & with much apprehension plugged it in, flipped the switch & the lights didn't go off. The Pro Melt switch light came on & I heard sounds of the pot heating up. I'll give it a real test when "the crud" leaves completely.

Replacement of the switch is possible w/o removal of the sheet metal.

MORAL: 78 year old brains don't work as well as they once did.

[dikman]

At least it was an easy fix.

[lightman]

Your not the first guy to install a switch up side down. Glad you got it figured out.

[Mal Paso]

Glad you got it fixed.

I got 2 dozen boolits cast with my new old Pro Melt before the dripping got too bad. It was the dripping down the outside of the nozzle that got my attention. Both the valve rod and nozzle are bent and there is a leak between the nozzle and pot. It's going to take A Lot more work. LOL

[jsizemore]

Glad you got it fixed.

I got 2 dozen boolits cast with my new old Pro Melt before the dripping got too bad. It was the dripping down the outside of the nozzle that got my attention. Both the valve rod and nozzle are bent and there is a leak between the nozzle and pot. It's going to take A Lot more work. LOL

My invoice from RCBS:

Item#- 55005 Description- 01003836-Lead Pot Reported Issue- Worn
Item#- 81114 Description- Nozzle Shut-Off Pin Reported Issue- Broken/Cracked

Customer Service- 800-379-1732

Got mine in about a week. That was shipped on 8/25/2017. Good Luck