Create an account Home  ·  ·  Forums  ·  ·  Articles  ·  ·  Downloads  ·  ·  Photo Gallery  
Login
Nickname

Password

Don't have an account yet? You can create one here.

Navigation
· Home
· Article Archive
· Article Submit
· Downloads
· FAQ
· Forums
· Members List
· Photo Gallery
· Private Messages
· Web Links
· Your Account

Search Articles



Forums

Wiper motor...which is the correct one?
Lead additive, one more question.
M31C mount with or without replica weapon
Backfire and Hesitation
Wanted: Steering column and shaft for M38-1952, or late CJ2A
2024 CT. MILITARY VEHICLE SHOW AND FLEA MARKET- JUNE 15,2024
Brake Line
How to link full size photos in posts
Clutch release bearing support cast tab for return spring
T90 case replacement required?

Willys M Jeeps Forums


willysmjeeps.com :: View topic - Question about testing new wiring harness
 Forum FAQForum FAQ   SearchSearch   UsergroupsUsergroups   ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Question about testing new wiring harness

 
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base
View previous topic :: View next topic  
Author Message
Kendall
Member


Joined: Feb 25, 2006
Posts: 344
Location: Wichita, KS

PostPosted: Sun Jul 25, 2021 5:02 pm    Post subject: Question about testing new wiring harness Reply with quote

So I am slowly nearly the end of the restoration of my 1952 M38. The engine is out at the rebuilders and I have installed a new wiring harness. Is it possible to test the hook-ups of this harness while I am waiting on the engine? I was thinking I could jump 24v from another jeep to the #10 post of the regulator harness and to a ground to power the master light switch to check lights, horn, etc. Or is there another way to do it?
Thanks,
Kendall
_________________
1951 M38
1952 M38
1952 M38A1
1942 Dodge WC-55
1951 M100 trailer
1942 Ben Hur trailer
Back to top
View user's profile Send private message
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 16225
Location: Wisconsin

PostPosted: Sun Jul 25, 2021 6:06 pm    Post subject: Reply with quote

Curious! The missing engine has no real impact on operating the rest of the electrical system. Where are your batteries?
_________________
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.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Kendall
Member


Joined: Feb 25, 2006
Posts: 344
Location: Wichita, KS

PostPosted: Sun Jul 25, 2021 8:16 pm    Post subject: Reply with quote

Correct, but without the engine I don't have the generator, starter, distributor nor regulator connected to the electrical system. This jeep was 12v and that battery is dead and am waiting for the engine to get completed before I buy two new batteries.
_________________
1951 M38
1952 M38
1952 M38A1
1942 Dodge WC-55
1951 M100 trailer
1942 Ben Hur trailer
Back to top
View user's profile Send private message
RonD2
Member


Joined: Oct 02, 2014
Posts: 1887
Location: South Carolina, Dorchester County

PostPosted: Sun Jul 25, 2021 9:57 pm    Post subject: Reply with quote

Hi Kendall,
Just curious, do you have reason to think a new harness is defective or got hooked up wrong?
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

Back to top
View user's profile Send private message Send e-mail
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 16225
Location: Wisconsin

PostPosted: Mon Jul 26, 2021 1:06 am    Post subject: Reply with quote

Quote:
Correct, but without the engine I don't have the generator, starter, distributor nor regulator connected to the electrical system.


Still the missing water temp sender, oil press sender, generator, starter and distributor have no real impact on pressing on with the harness installation and ops checking of circuits. You will simply ignore those three circuits until you have your engine installed. There's no reason you cannot leave the regulator connected to the firewall harness. You can check the sender wires and distributor lead for power with a voltmeter.

As for the old dead 12V battery, I would not risk another guys jeep's electrical system using it to power my harness checkout. Just disconnect his positive and chassis ground posts. Leave the short series wire connected between his batteries. then jumper just his pair of batteries to your jeep. Or just borrow two 12V batteries and hook them up to your jeep.
_________________
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.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
Kendall
Member


Joined: Feb 25, 2006
Posts: 344
Location: Wichita, KS

PostPosted: Mon Jul 26, 2021 11:40 am    Post subject: Reply with quote

No reason to believe the wiring harness is defective, I built it myself (haha). With it being new (and built by myself) I just thought I should test connections and everything as the next step.
Wes, the other "guys" jeep is my other M38 so no concern, but still how do you suggest hooking up the 24v from that jeep to this jeep? Back to my original post, can I just hook the positive lead to the #10 wire and the negative lead to the frame ground?
Thanks for your help,
Kendall
_________________
1951 M38
1952 M38
1952 M38A1
1942 Dodge WC-55
1951 M100 trailer
1942 Ben Hur trailer
Back to top
View user's profile Send private message
wesk
Site Administrator
Site Administrator


Joined: Apr 04, 2005
Posts: 16225
Location: Wisconsin

PostPosted: Tue Jul 27, 2021 1:12 am    Post subject: Reply with quote

Perhaps I do not understand where you are right now. If I had a need to test any harness I would prefer to do it before installing the harness with low voltage source. Once I had the harness in the jeep I would prefer to have everything installed first including the battery cables and regulator for a proper and safe test environment. I cannot advise you how to connect to a partially installed harness without seeing the entire setup.
_________________
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.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php
Back to top
View user's profile Send private message Send e-mail Visit poster's website
RonD2
Member


Joined: Oct 02, 2014
Posts: 1887
Location: South Carolina, Dorchester County

PostPosted: Tue Jul 27, 2021 8:28 pm    Post subject: Reply with quote

Agree.

I was taught (on stuff where peoples' lives are on the line) that the first step to check out a newly installed harness (after it's been checked and double-checked that it's properly assembled and connected to everything it's supposed to be connected to) is to "ring it out". That means a continuity check, every wire, point to point. A continuity check is done without power applied using an ohm meter. It also assumes that individual components like horns and lights and analog switches have already been checked good before installing them to the harness.

You can cheat using a tone generator or a DVM that has a tone diode checker. Or the old school analog ohm meter is always good. Use a short alligator test lead on the distant end to ground it and if you get zero ohms it's a good check. If you can't connect everything you can still check the wire, but have to make certain it's isolated, meaning the connector or terminal isn't touching anything. Only after a good ringing is the harness cleared for applying power. Naturally, you have to trace and correct circuits that don't ring good according to the wiring schematic diagram.

Not sure I'd put myself through all this for a harness that I carefully built and installed myself ----> unless I knew I got seriously distracted or confused doing it.......a chance you take. Once you put power to it, it's too late to wonder if things start melting and smoking.

Good luck!
_________________
Ron D.
1951 M38 Unknown Serial Number
1951 M100 Dunbar Kapple 01169903 dod 5-51

“The only good sports car that America ever made was the Jeep."
--- Enzo Ferrari

Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    willysmjeeps.com Forum Index -> Technical Knowledge Base All times are GMT - 6 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

Powered by phpBB © 2001 phpBB Group
Forums ©

 



PHP-Nuke Copyright © 2005 by Francisco Burzi. This is free software, and you may redistribute it under the GPL. PHP-Nuke comes with absolutely no warranty, for details, see the license.