I have a 52 m38. The passenger side head light lights up buy it self. This has happen four the last three days. Also the driver side tail light. When i move the light switch i can get it to turn off. Is this a bad light control switch ?
Any input would be appreciated. [/b]
Head lights and tail lights
- cowboy2
- Member
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- Location: May, Texas
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RonD2
- Jeep Legend

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Hey Cowboy,
Given that this just happened 3 days ago (and before that all your lights worked correctly), it sure sounds like your switch went bad to me. There's old brittle plastic parts inside them that broke easy even back in the day if not operated correctly (using the unlocking lever before switching anything). See the manual about that.
You might also check for loose, dirty, or corroded wiring around the switch and light connector(s). Or recall anything else you might have been doing to the jeep in the last 3 days that could've maybe caused it.
Does your switch have the oval face or a triangular face? The oval face switch is the later and more common type and is sealed, not repairable. The early triangular face switch can be opened for repair, but parts for it are very hard to find. Replacement NOS oval switches are all over the place for sale at about $75 each. Early triangular switches NOS are very hard to find at about twice that price if you're lucky.
By the way, this is the Wanted (to buy stuff) part of the forum. I'm guessing you meant to ask your question in the Technical Knowledge Base part of the forum? Wes will probably move it so you get better coverage for answers.....
Is your M38 all original 24 volt and wiring, unmolested?
Good luck!
Given that this just happened 3 days ago (and before that all your lights worked correctly), it sure sounds like your switch went bad to me. There's old brittle plastic parts inside them that broke easy even back in the day if not operated correctly (using the unlocking lever before switching anything). See the manual about that.
You might also check for loose, dirty, or corroded wiring around the switch and light connector(s). Or recall anything else you might have been doing to the jeep in the last 3 days that could've maybe caused it.
Does your switch have the oval face or a triangular face? The oval face switch is the later and more common type and is sealed, not repairable. The early triangular face switch can be opened for repair, but parts for it are very hard to find. Replacement NOS oval switches are all over the place for sale at about $75 each. Early triangular switches NOS are very hard to find at about twice that price if you're lucky.
By the way, this is the Wanted (to buy stuff) part of the forum. I'm guessing you meant to ask your question in the Technical Knowledge Base part of the forum? Wes will probably move it so you get better coverage for answers.....
Is your M38 all original 24 volt and wiring, unmolested?
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
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
- wesk
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If you will use the web site to full advantage, IE reviewing my photo albums, particularly the m-series lighting sub-album and our downloads pages you will find a free ton of data begging folks to utilize it.
My Photo Albums: http://www.willysmjeeps.com/v2/modules. ... _album.php
Our downloads pages: http://www.willysmjeeps.com/v2/modules. ... =Downloads


The two Bendix switches have cases that are fastened with screws and easily disassembled. The later throwaway switches have crimped cases and usually the crimps break when toyed with. The current production light switches actually connect right up to the old style cabled plug and will work fine but are quite expensive NOS.
The most common issue with all the Bendix & crimped case switches are wear on the switch slide surfaces and carbon tracking. A simple cleaning of these contact surfaces solves most issues. People have posted a certain degree of success opening the crimped cases and cleaning contact surfaces so since they are a throwaway switch why not give it a try?
My Photo Albums: http://www.willysmjeeps.com/v2/modules. ... _album.php
Our downloads pages: http://www.willysmjeeps.com/v2/modules. ... =Downloads


The two Bendix switches have cases that are fastened with screws and easily disassembled. The later throwaway switches have crimped cases and usually the crimps break when toyed with. The current production light switches actually connect right up to the old style cabled plug and will work fine but are quite expensive NOS.
The most common issue with all the Bendix & crimped case switches are wear on the switch slide surfaces and carbon tracking. A simple cleaning of these contact surfaces solves most issues. People have posted a certain degree of success opening the crimped cases and cleaning contact surfaces so since they are a throwaway switch why not give it a try?
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
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- Kendall
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Is your wiring laid out like it originally was intended? Since there is only one power source to both headlights low beam and one to both headlights high beam (it splits at the double-Douglas connector before the driver's headlight) it seems odd that only one headlight would shine.
Kendall
Kendall
1951 M38
1952 M38
1952 M38A1
1942 Dodge WC-55
1951 M100 trailer
1942 Ben Hur trailer
1952 M38
1952 M38A1
1942 Dodge WC-55
1951 M100 trailer
1942 Ben Hur trailer
- wesk
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Cowboy,
This would be a good time to set your system straight with us.
2 - When you say "Lights up by itself" do you mean it suddenly comes on with the switch off???
3 - Have you checked all lamps (Bulbs) to ensure they all work?
The light switch powers the dimmer switch. The dimmer switch decides on which beam gets illuminated Hi/Lo.
The left rear red steady lamp is the service drive tail lamp. It comes on when you select service drive with the light switch.
This would be a good time to set your system straight with us.
1 - Is it wired stock?The passenger side head light lights up buy it self. This has happen four the last three days. Also the driver side tail light. When i move the light switch i can get it to turn off. Is this a bad light control switch ?
2 - When you say "Lights up by itself" do you mean it suddenly comes on with the switch off???
3 - Have you checked all lamps (Bulbs) to ensure they all work?
The light switch powers the dimmer switch. The dimmer switch decides on which beam gets illuminated Hi/Lo.
The left rear red steady lamp is the service drive tail lamp. It comes on when you select service drive with the light switch.
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
- cowboy2
- Member
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- Joined: Mon Jan 13, 2020 6:00 pm
- Location: May, Texas
Lights
Wiring is original
Lights come on with switch off
A bulb check showed all o.k.
The only thing i add to the jeep were turn signals (24 volt) and that was 6 months ago.
When i switch on all lights they all work but the driver side tail light.
Cowboy
Lights come on with switch off
A bulb check showed all o.k.
The only thing i add to the jeep were turn signals (24 volt) and that was 6 months ago.
When i switch on all lights they all work but the driver side tail light.
Cowboy
- wesk
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The driver's side tail light does not work when the light switch is in the service drive position?When i switch on all lights they all work but the driver side tail light.
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