Stewart Warner Amp gauge short circuit?
- Chuck Lutz
- Gee Addict
- Posts: 26829
- Joined: Wed Jun 28, 2006 7:00 am
- Location: Jeep Heaven
Re: Stewart Warner Amp gauge short circuit?
Bertrand:
The 50-0-50 Amp Gauge with the "F" at the bottom of the face has FOUR threaded "studs" attached to the body of the gauge. The TOP and BOTTOM use a "C" shaped bracket to hold the gauge to the back of the dash. The LEFT and RIGHT posts are insulated from the body of the gauge and are for mounting the wiring harnesses.
I can see that the bezel has been removed/replaced on the body of the gauge. If you mean there are only THREE studs on the body then the body is not original to the gauge. If you mean it has four but one is broken off then the body is probably original to a SW gauge. If you can post another pic of the back of the gauge, we can confirm what I just posted above.
The 50-0-50 Amp Gauge with the "F" at the bottom of the face has FOUR threaded "studs" attached to the body of the gauge. The TOP and BOTTOM use a "C" shaped bracket to hold the gauge to the back of the dash. The LEFT and RIGHT posts are insulated from the body of the gauge and are for mounting the wiring harnesses.
I can see that the bezel has been removed/replaced on the body of the gauge. If you mean there are only THREE studs on the body then the body is not original to the gauge. If you mean it has four but one is broken off then the body is probably original to a SW gauge. If you can post another pic of the back of the gauge, we can confirm what I just posted above.
Chuck Lutz
GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947
GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947
- Division Leclerc
- Sergeant Major of the Gee
- Posts: 282
- Joined: Mon Mar 06, 2017 6:41 am
- Location: Orléans, FRANCE
Re: Stewart Warner Amp gauge short circuit?
- Chuck Lutz
- Gee Addict
- Posts: 26829
- Joined: Wed Jun 28, 2006 7:00 am
- Location: Jeep Heaven
Re: Stewart Warner Amp gauge short circuit?
Bertrand….
Yes, you are missing altogether one of the mounting studs and I believe the one still present is too short. If you had an opportunity to find another BODY for a SW AMPERES gauge, I would suggest you swap out that body for one that is in better condition with good mounting studs on it.
Yes, you are missing altogether one of the mounting studs and I believe the one still present is too short. If you had an opportunity to find another BODY for a SW AMPERES gauge, I would suggest you swap out that body for one that is in better condition with good mounting studs on it.
Chuck Lutz
GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947
GPW 17963 4/24/42 Chester, PA. USA 20113473 (USA est./Tom W.)
Bantam T3-C 1947
- Division Leclerc
- Sergeant Major of the Gee
- Posts: 282
- Joined: Mon Mar 06, 2017 6:41 am
- Location: Orléans, FRANCE
Re: Stewart Warner Amp gauge short circuit?
Chuck Lutz wrote: ↑Wed Jun 20, 2018 11:17 amBertrand….
Yes, you are missing altogether one of the mounting studs and I believe the one still present is too short. If you had an opportunity to find another BODY for a SW AMPERES gauge, I would suggest you swap out that body for one that is in better condition with good mounting studs on it.
OK Chuck, many thanks for your help.
- YLG80
- G-Lieutenant General
- Posts: 4095
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Stewart Warner Amp gauge short circuit?
@ Bertrand
If not, your ammeter is in short-circuit with the ground (housing), for sure.
It would produce a big short-circuit if you connect that ammeter !
There are ammeter gauges without the 2 additional studs perpendicular to the terminals like this one.
I don't like that design more prone to short-circuits but it can be used providing that the bracket insulators are of a good and durable quality. Yves
I'm wondering if the parts pointed by the arrows are insulators?If not, your ammeter is in short-circuit with the ground (housing), for sure.
It would produce a big short-circuit if you connect that ammeter !
There are ammeter gauges without the 2 additional studs perpendicular to the terminals like this one.
I don't like that design more prone to short-circuits but it can be used providing that the bracket insulators are of a good and durable quality. Yves
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
- YLG80
- G-Lieutenant General
- Posts: 4095
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Stewart Warner Amp gauge short circuit?
The picture here above shows a dangerous assembly which is not correct vs the original drawing!
For those interested in the repair of the ammeter gauge GPW-10850/ A-440047, here is the drawing showing the assembly and particularly the insulator positions in color.
Too bad that the link shunt GPW-10837 has no ohm value mentioned on that drawing.
Does anyone have an information about that "TANK AUTOMOTIVE CENTER BULLETIN n°3" mentioned on the drawing?
Yves
Drawing
For those interested in the repair of the ammeter gauge GPW-10850/ A-440047, here is the drawing showing the assembly and particularly the insulator positions in color.
Too bad that the link shunt GPW-10837 has no ohm value mentioned on that drawing.
Does anyone have an information about that "TANK AUTOMOTIVE CENTER BULLETIN n°3" mentioned on the drawing?
Yves
Drawing
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
-
- G-Major General
- Posts: 2860
- Joined: Fri Jan 08, 2010 4:32 pm
- Location: Arcadia & Johannesburg Ca.
Re: Stewart Warner Amp gauge short circuit?
Getting back to the original post, I was using a 30+ / 30- amp gauge for 45+ years in a street rod. When I had the gauges restored recently, the gauge shop asked me why it was only a 30 max gauge. I said because I was 17, and didn't know any better. He told me to run a "shunt", or in other words, a small wire across the poles as this might not be totally accurate in reading, but will stop the needle of the gauge from "pegging out".
But also, never, never, hook the gauge up to a battery alone.
But also, never, never, hook the gauge up to a battery alone.
Dino Falabrino
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43
1928 Model A Roadster Pickup
1930 Model A Tudor
1968 Taco Minibike
On the "G" since 1998.
1943 GPW 102310 DOD 3-3-43
1928 Model A Roadster Pickup
1930 Model A Tudor
1968 Taco Minibike
- YLG80
- G-Lieutenant General
- Posts: 4095
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Stewart Warner Amp gauge short circuit?
You can calculate a shunt value so that the reading will simply be doubled and you write X2 near the gauge..
Just carefully measure the original shunt and make another one with the same value.
Connect the new one in // with the original.
As the ohm value of an original shunt is very, very low, you should ask to someone to measure it in a lab, i.e in a local school.
That's an excellent exercise for a student ! They could even build the second shunt to be placed in //.
The Wheatstone bridge: https://en.wikipedia.org/wiki/Wheatstone_bridge
Yves
Just carefully measure the original shunt and make another one with the same value.
Connect the new one in // with the original.
. I guess you are talking about the length not the sectiona small wire across the poles
As the ohm value of an original shunt is very, very low, you should ask to someone to measure it in a lab, i.e in a local school.
That's an excellent exercise for a student ! They could even build the second shunt to be placed in //.
The Wheatstone bridge: https://en.wikipedia.org/wiki/Wheatstone_bridge
Yves
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
-
- Sergeant Major of the Gee
- Posts: 258
- Joined: Thu Mar 10, 2016 11:19 pm
- Location: Belgium
Re: Stewart Warner Amp gauge short circuit?
For what it is worth: I used ceramic "hat" insulators or spacers.
They go over the poles/studs and contain a narrow section which fit in the hole of the housing. So you never have any contact between the electrical poles and the housing. I also used a ceramic spacer to make sure that there is no contact possible between the shunt and the housing.
I want to avoid any contact between the positive charges on the poles and the negative/ground on the housing.
They go over the poles/studs and contain a narrow section which fit in the hole of the housing. So you never have any contact between the electrical poles and the housing. I also used a ceramic spacer to make sure that there is no contact possible between the shunt and the housing.
I want to avoid any contact between the positive charges on the poles and the negative/ground on the housing.
-
- G-Colonel
- Posts: 1926
- Joined: Mon Oct 16, 2017 1:01 pm
- Location: San Diego, CA
Re: Stewart Warner Amp gauge short circuit?
Ceramic is the way to go. No worries about heat from the shunt.
52 M38 2X, '52 M37, '44 WC51, '42 WC 56/57, '50 CJ-V35(U), '42 GPW, '44 M3A1 Scout Car, 2010 M-Gator
- YLG80
- G-Lieutenant General
- Posts: 4095
- Joined: Fri Aug 05, 2011 9:45 am
- Location: near Namur, Belgium
- Contact:
Re: Stewart Warner Amp gauge short circuit?
Yes elegant solution.
But do not over tighten the nuts .
I've turned my insulators in Ertalon or Teflon (don't remember exactly) with my mini lathe.
Electronic components distributors have similar pass through insulators of various sizes like these in Nylon or PET up to M8:
https://benl.rs-online.com/web/c/fasten ... nsulators/
Yves
But do not over tighten the nuts .
I've turned my insulators in Ertalon or Teflon (don't remember exactly) with my mini lathe.
Electronic components distributors have similar pass through insulators of various sizes like these in Nylon or PET up to M8:
https://benl.rs-online.com/web/c/fasten ... nsulators/
Yves
Ford GPW 1943 - Louisville - DoD 12-7-43
serial 164794
serial 164794
-
- Sergeant Major of the Gee
- Posts: 258
- Joined: Thu Mar 10, 2016 11:19 pm
- Location: Belgium
Re: Stewart Warner Amp gauge short circuit?
Impossible to over tight them. The thread is so fragile after 75+ years that it tears off before you can break the ceramic.
Don't ask me how I know...
Don't ask me how I know...
Who is online
Users browsing this forum: compostwerks, DogDoc, Google [Bot], loose nut dan and 56 guests