Temp gauge wiring, easy question

This is the place to get help with technical matters concerning your M151 jeep

Moderators: rickf, raymond, Mr. Recovery

Post Reply
UDTDave
Corporal
Corporal
Posts: 31
Joined: October 12th, 2017, 9:31 pm
Location: Navasota, TX

Temp gauge wiring, easy question

Unread post by UDTDave » November 6th, 2017, 7:41 pm

Looking at the TM it shows the power wire at the top. Since gauges have wires left and right on the back of the gauge does that mean the power wire is on the left facing the gauge and the wire to the sensor is on the righ?
1944 MB sold
M37A1 sold

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Temp gauge wiring, easy question

Unread post by rickf » November 6th, 2017, 7:57 pm

power goes to positive on gauge and negative on gauge goes to sender.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

UDTDave
Corporal
Corporal
Posts: 31
Joined: October 12th, 2017, 9:31 pm
Location: Navasota, TX

Re: Temp gauge wiring, easy question

Unread post by UDTDave » November 6th, 2017, 8:18 pm

I kinda figured that. Which terminal is positive? I do not see any markings on the gauge unless I am missing something.
1944 MB sold
M37A1 sold

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Temp gauge wiring, easy question

Unread post by rickf » November 6th, 2017, 9:10 pm

Pages 5-145 and 5-144 in the -20-1 manual available on here for download shows the position of the wires on the gauge. With "pictures and arrows describing the meaning of each one". :roll: :lol: Sorry, had an Arlo Guthrie flashback there.

Here is the link to the manual

http://www.g838.org/g838_manuals/TM%209 ... ay1982.pdf
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

UDTDave
Corporal
Corporal
Posts: 31
Joined: October 12th, 2017, 9:31 pm
Location: Navasota, TX

Re: Temp gauge wiring, easy question

Unread post by UDTDave » November 6th, 2017, 10:48 pm

Thanks! I actually have the manuals I just don’t know how to use them yet. I looked at the schematic and not 5-144 and 145. So the answer is, since circuit 33 goes to the sensor and that is on the left facing the gauge the power circuit is 27 on the right facing the gauge. Damn thing still does not work. Since this is a new gauge I guess it’s on to a new sensor. Thank goodness it only has one wire. Thanks for the newbie help.
1944 MB sold
M37A1 sold

User avatar
D Pizzoferrato
Master Sergeant
Master Sergeant
Posts: 342
Joined: May 1st, 2010, 8:16 am

Re: Temp gauge wiring, easy question

Unread post by D Pizzoferrato » November 7th, 2017, 8:54 am

If you have original gauges, look at the Packard connector boots on the gauge for a clear clue. One connector is smooth, the other will have raised ridges around the outer circumference. These will mate to the Male Packard insert on the harness, which are similarly formed.
Visit our Website! www.odcloth.com for your Canvas needs

Visit our AM151A2 restoration page http://www.odcloth.com/mymutt/1979am151a2.html

Visit our PBR Restoration Site. http://www.pbr6927.com

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Temp gauge wiring, easy question

Unread post by rickf » November 7th, 2017, 10:57 am

UDTDave wrote:Thanks! I actually have the manuals I just don’t know how to use them yet. I looked at the schematic and not 5-144 and 145. So the answer is, since circuit 33 goes to the sensor and that is on the left facing the gauge the power circuit is 27 on the right facing the gauge. Damn thing still does not work. Since this is a new gauge I guess it’s on to a new sensor. Thank goodness it only has one wire. Thanks for the newbie help.
Are you checking this with the gauge panel out of the dash/ If it is an A2 do you have the ground wire hooked up to the gauge panel? If it is an A1 you will have to put a jumper wire from ground to the panel. The gauge panel has to be grounded. And looking at the back of the gauges the power (#27) goes to the left terminal but as Dave said match the boots.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

UDTDave
Corporal
Corporal
Posts: 31
Joined: October 12th, 2017, 9:31 pm
Location: Navasota, TX

Re: Temp gauge wiring, easy question

Unread post by UDTDave » November 10th, 2017, 11:03 pm

Thanks!
1944 MB sold
M37A1 sold

kmam
Sergeant Major
Sergeant Major
Posts: 524
Joined: June 6th, 2015, 7:39 am
Location: Kuranda, Far North Queensland, Australia

Re: Temp gauge wiring, easy question

Unread post by kmam » November 11th, 2017, 6:42 am

I don’t think that grounding the panel makes any difference as the ground to the gauge is supplied by the sensor. The resistance between the sensor input and ground determines the voltage drop at the sensor and thus the amount of movement of the gauge. In the case of the temp gauge that resistance is determined by the temperature experienced by the sensor.

Grounding the panel is required for the panel lights.
Howard

Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ

User avatar
rickf
General
General
Posts: 19738
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: Temp gauge wiring, easy question

Unread post by rickf » November 11th, 2017, 9:43 am

And for the volt meter but I have seen some weird stuff happen with open grounds so better safe than guessing.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

kmam
Sergeant Major
Sergeant Major
Posts: 524
Joined: June 6th, 2015, 7:39 am
Location: Kuranda, Far North Queensland, Australia

Re: Temp gauge wiring, easy question

Unread post by kmam » November 11th, 2017, 10:32 am

Fair enough.
Howard

Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ

UDTDave
Corporal
Corporal
Posts: 31
Joined: October 12th, 2017, 9:31 pm
Location: Navasota, TX

Re: Temp gauge wiring, easy question

Unread post by UDTDave » November 12th, 2017, 12:36 am

Could Teflon tape on the sensor threads make a difference?
1944 MB sold
M37A1 sold

kmam
Sergeant Major
Sergeant Major
Posts: 524
Joined: June 6th, 2015, 7:39 am
Location: Kuranda, Far North Queensland, Australia

Re: Temp gauge wiring, easy question

Unread post by kmam » November 12th, 2017, 1:03 am

I believe so. If there is enough tape to isolate the sensor body from the block and therefore prevent the earth return connection then the circuit is broken and will not work.
Howard

Daimler Ferret Mk 1/2
AM General M151A2
Austin Champ

Post Reply