Testng Rotary Light Switch

1941 - 1945, MB, GPW Technical questions and discussions, regarding anything related to the WWII jeep.
Post Reply
User avatar
HQ327
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 427
Joined: Sun Jul 18, 2004 7:26 pm
Location: Fayetteville, NC

Testng Rotary Light Switch

Post by HQ327 » Fri Mar 16, 2018 12:01 am

How does one (me) test to see if my rotary switch has gone bad?

Jeff


Wolfman
G-Lieutenant General
G-Lieutenant General
Posts: 6878
Joined: Sat Jan 12, 2008 5:25 am
Location: Tipton,In.

Re: Testng Rotary Light Switch

Post by Wolfman » Fri Mar 16, 2018 6:10 am

Is it in or out on the bench ??
If out, a jumper battery with "+" connected to the circuit breaker with a jumper wire and an ice pick test light connected to the battery "-" post would work.
You are interested in two things.
Does it have power to the switch and is there power coming out to the correct terminals in the different switch positions.
This can be checked with a test light or a volt meter.
If the switch has failed completely, the circuit breaker on the back would be suspect. This is pretty common.
The on board circuit breaker can be removed and an in-line circuit breaker, of the same amperage, installed in the wire to the light switch, from the amp gauge.
If you are getting power through the breaker but nothing out, an internal problem with the switch itself would be likely.
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

cjv-35
G-Colonel
G-Colonel
Posts: 1931
Joined: Mon Dec 18, 2006 5:06 pm
Location: San Mateo, Ca

Re: Testng Rotary Light Switch

Post by cjv-35 » Sat Mar 17, 2018 11:23 am

One can pry the crimp gently back around the unit and expose the inside. You will find a small ball bearing and spring which ride on a copper plate with indents for each lighting position. Sometimes all the switch needs is for the contact plate to be cleaned of rust and corrosion and your switch will work fine.

User avatar
HQ327
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 427
Joined: Sun Jul 18, 2004 7:26 pm
Location: Fayetteville, NC

Re: Testng Rotary Light Switch

Post by HQ327 » Thu Mar 22, 2018 1:26 pm

Wolfman wrote:
Fri Mar 16, 2018 6:10 am
Is it in or out on the bench ??
If out, a jumper battery with "+" connected to the circuit breaker with a jumper wire and an ice pick test light connected to the battery "-" post would work.
You are interested in two things.
Does it have power to the switch and is there power coming out to the correct terminals in the different switch positions.
This can be checked with a test light or a volt meter.
If the switch has failed completely, the circuit breaker on the back would be suspect. This is pretty common.
The on board circuit breaker can be removed and an in-line circuit breaker, of the same amperage, installed in the wire to the light switch, from the amp gauge.
If you are getting power through the breaker but nothing out, an internal problem with the switch itself would be likely.
I suspect the circuit braker failed. Thank you.

Jeff

Wolfman
G-Lieutenant General
G-Lieutenant General
Posts: 6878
Joined: Sat Jan 12, 2008 5:25 am
Location: Tipton,In.

Re: Testng Rotary Light Switch

Post by Wolfman » Fri Mar 23, 2018 5:26 am

Your Welcome !
Mike Wolford
CJ-2A
VEP GPW
Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

User avatar
HQ327
Sergeant Major of the Gee
Sergeant Major of the Gee
Posts: 427
Joined: Sun Jul 18, 2004 7:26 pm
Location: Fayetteville, NC

Re: Testng Rotary Light Switch

Post by HQ327 » Fri Mar 23, 2018 5:38 pm

Seems like no one has any of the circuit breakers in stock.

Can (could) a 30 Amp fused be used in lieu of the circuit breaker?

Jeff


Post Reply

Return to “MB GPW Technical Knowledge Base”

Who is online

Users browsing this forum: DogDoc, loose nut dan and 71 guests