IH8Wiring

[MDH33]

I just lost the interior lights and all running lights on my 40.

I have a feeling that driving it on the sloppy, mag chloride coated roads has shorted out something. The headlights, brake lights, turn signals and hazards work fine. but no instrument panel lights, running lights or side markers. I've dealt with bad grounds in the tail lights before, but that only effected the turn signals... All the fuses look good, but I'm not sure which controls the lights specifically or if the headlights and brakes are a seperate fuse??. Any help appreciated. I hate wiring.

 

[Rezarf]

Martin-

Here are few things to try.

1. Check the fuse at the block.
2. Try to turn/wiggle each of the front turn signals, sometimes that does enough to the ground to get them going again.
3.There is also a connection on your inner fender, it is a bullet connector for your parking lights. Might check there too. Mine is green. About the size of a pen cap.
4. I am not sure why all your lights would go out inside. Maybe something in the switch.

Sorry man, wiring can be frustrating.

Drew

 

[corsair23]

I just lost the interior lights and all running lights on my 40.

All the fuses look good, but I'm not sure which controls the lights specifically or if the headlights and brakes are a seperate fuse??. Any help appreciated. I hate wiring.

x2 on hating wiring

Do you have an EWD for the 40? If not, I've got a laminated 11x17" one for a '74 (also have one for '75 and '76 years) that you're welcome to borrow - I'm thinking it should be close enough to a '73

In looking at what I have (and assuming I'm reading it right) the side marker lights run off the same green wire that the turn signals/brake lights do (re: what Drew said about the bullet connector) with separate grounds for each. They all appear to go to the "Light control switch" and to the "Panel Light" on the combination meter (i.e. gauge cluster). It appears these all run through the Light Control Switch (green/red wire) which is wired out to/off the 15A fuse in the fuse block in position 1 labeled "Tail". The Light Control Switch also has a red wire going to the 20A fuse, position 8, labeled "Head" that also goes over to the "Turn Signal Switch & Dimmer Switch" (position is lableled "F", first one).

Ok...not sure if any of the above was helpful but it should confirm that your head lights are/should be running off the 20A fuse in position 8 on the fuse block and the side markers/tail lights/turn signals? are/should be working off the 15A fuse in position 1 on the fuse block. It appears what everything has in "common" would be the Light Control Switch and the Turn Signal Switch & Dimmer Switch (which I thought was integrated into the Light Control Switch?). Oh, and just to add more confusion there is a whole mess of stuff connected to the "Turn Signal Switch & Dimmer Switch" (head lights, tail lights, turn signals, trailer socket, stop light switch) including a lead to/from the "Hazard Warning Signal Switch"

Let me know if you need to borrow the diagram...I could bring it to the meeting.

 

[treerootCO]

I chased the same problem on my 40. Top fuse I think. I had done everything and it turned out the fuse was defective. Pull on both ends of all your fuses, if they pull apart, replace them.

 

[MDH33]

Thanks for the help guys. I will start troubleshooting it today since it's supposed to be a balmy 26 degrees out. hopefully it is as simple as a ground or fuse and not Mag Chloride eating it's way through my wiring harness.

Jeff, thanks for the offer to borrow your wiring diagrams. '73-'74 was the year that they switched from the round tail lights to the square ones, 9/73 I think. Slightly different, but your explanation of the fuse connections helped. Thanks.

 

[corsair23]

Jeff, thanks for the offer to borrow your wiring diagrams. '73-'74 was the year that they switched from the round tail lights to the square ones, 9/73 I think. Slightly different, but your explanation of the fuse connections helped. Thanks.

No problem...Did you check MUD for earlier? I know I've seen some on there before. Here is a link to a '71 wiring diagram I found in the tech links...

1971 Wiring Diagram

Other MUD tech links here - electrical stuff is toward the bottom, left side