ignition switch hook up
- sgtkish
- Member
- Posts: 20
- Joined: Sat Nov 21, 2015 6:00 pm
ignition switch hook up
Does anyone have a pic of where wire 27 goes to the dash? All the diagrams don't show in detail where it plugs in at, or if its just a ground you strap to the metal dash. I would like to see how the original on off switch is hooked up all together. Thanks
- sgtkish
- Member
- Posts: 20
- Joined: Sat Nov 21, 2015 6:00 pm
Re: ignition switch hook up
And what is 85 even there for if it doesn't hook up to another plug?sgtkish wrote:Does anyone have a pic of where wire 27 goes to the dash? All the diagrams don't show in detail where it plugs in at, or if its just a ground you strap to the metal dash. I would like to see how the original on off switch is hooked up all together. Thanks
- 4x4M38
- Jeep Legend

- Posts: 3487
- Joined: Thu May 29, 2014 6:00 pm
- Location: Texas Hill Country
Wire 27 from the switch feeds your instruments
through the breaker/spider on the early
M38. Later units did not have the instrument
breaker.
"85 is the spare accessory power lead on the main power/ignition switch. It was often used for the heater kits and if the mechanical regulator was replaced with a transistor regulator the amp meter would then be swapped with a volt meter. The 8 & 9 wires for the amp meter were then no longer used and the 85 wire was used to power the volt meter and a ground was run from the volt meter to the firewall.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100"
through the breaker/spider on the early
M38. Later units did not have the instrument
breaker.
"85 is the spare accessory power lead on the main power/ignition switch. It was often used for the heater kits and if the mechanical regulator was replaced with a transistor regulator the amp meter would then be swapped with a volt meter. The 8 & 9 wires for the amp meter were then no longer used and the 85 wire was used to power the volt meter and a ground was run from the volt meter to the firewall.
_________________
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100"
- 4x4M38
- Jeep Legend

- Posts: 3487
- Joined: Thu May 29, 2014 6:00 pm
- Location: Texas Hill Country
- sgtkish
- Member
- Posts: 20
- Joined: Sat Nov 21, 2015 6:00 pm
Thanks , I'm slowly getting the site down. I just figured that one out after you told me that. One more question. I have an m38a1 1952, and everywhere I look I can't find a breaker set up. Is this model not set up with any breakers, or is it just in the three lever switch?4x4M38 wrote:All of this info is available through the search function above,
and the many photo pages. Wes has several photos and diagrams
of the back of the instrument cluster showing wiring, gauges,
circuit breaker and wire clip for wires 17 and 85.
Take care,
- wesk
- Site Administrator

- Posts: 16465
- Joined: Sun Apr 03, 2005 6:00 pm
- Location: Wisconsin
- Contact:
Sgt Kish, Help us out on your posts and tell us which model jeep you have. Most of us just list it in our signature element along with a real first name. Makes the site more friendly.
If we are talking M38:
Are you looking closely to the m38 wiring diagrams in my M38 Electrical sub-album?

TM 9-804 early ops manual

TM 9-8012 late ops manual
If we are talking M38A1:
Are you looking at my M38A1 Electrical sub-album?

TM 9-804A early ops manual.

TM 9-8014 Late ops manual.
In each case it connects directly to the ignition switch pigtail.
To ID switch leads just go to my M series Electrical sub-album:

Two wire (3 terminal) and 3 wire Ignition switches.

Present day 4 wire switches available new.

Modern 4 wire switch pinouts.

Commercially available adapter harness from 4 packard to 4 douglas connectors.
85 is an accessory terminal.
If you will go to our Photo Gallery page you will see
On this page you will find several sheets you should download and keep handy when working a military vehicle wiring harness:
http://www.willysmjeeps.com/v2/modules.php?
name=Forums&file=posting&mode=reply&t=10252

Page one of wiring number index.

Page 2.
Note this chart is generic to all MV's but it has it's limitations. Where you see on page two #85 is a low pressure light circuit on a Deuce but on the M38 & M38A1 is is an unused circuit so the 85 lead qualifies as an accessory circuit.
There are 6 more pages there for you to download.
If we are talking M38:
Are you looking closely to the m38 wiring diagrams in my M38 Electrical sub-album?

TM 9-804 early ops manual

TM 9-8012 late ops manual
If we are talking M38A1:
Are you looking at my M38A1 Electrical sub-album?

TM 9-804A early ops manual.

TM 9-8014 Late ops manual.
In each case it connects directly to the ignition switch pigtail.
To ID switch leads just go to my M series Electrical sub-album:

Two wire (3 terminal) and 3 wire Ignition switches.

Present day 4 wire switches available new.

Modern 4 wire switch pinouts.

Commercially available adapter harness from 4 packard to 4 douglas connectors.
85 is an accessory terminal.
If you will go to our Photo Gallery page you will see
On this page you will find several sheets you should download and keep handy when working a military vehicle wiring harness:
http://www.willysmjeeps.com/v2/modules.php?
name=Forums&file=posting&mode=reply&t=10252

Page one of wiring number index.

Page 2.
Note this chart is generic to all MV's but it has it's limitations. Where you see on page two #85 is a low pressure light circuit on a Deuce but on the M38 & M38A1 is is an unused circuit so the 85 lead qualifies as an accessory circuit.
There are 6 more pages there for you to download.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules. ... _album.php