Lost all lights and horn

[Smokedtires]

Hey all, this has me scratching my head. Not sure where to go from here. I'm wondering if it might be something in the wiring bale at the bottom of the steering rod?

When off, I have 6.63v at starter, both sides of terminal box and coil. When running, 8v at generator. This is weird but maybe a hint of what's going on, I have 6.6v at right headlight, then 11v at left headlight and brake switch.

I tested the horn button at end of horn rod and had continuity when pressed. No power to horn when button is pressed.

The car did come with Signal-Stat 900 directionals wired to the cowl lights and brake lights. At the flasher I have 6v on one lug and 11v on another.

Car is 6v positive ground. Runs fine.

Any help is appreciated. Not sure on how to replace bulbs in cowl lights, another thing for me to research.

Thanks

 

[nkaminar]

Wiring issues. Make sure you have a good ground. At a fast idle, measure voltage between ground terminal of battery and a good ground on the engine. Do the same between the headlight buckets and a good ground on the engine with the headlights on.

Make sure the generator third brush is set properly for about 5 amps charging at a fast idle. You should have about 7 volts at the battery when the battery is fully charged and engine is at fast idle. 5 amps output from the generator without the headlights on will not be enough to run the headlights, so if you drive at night bump it up so that the generator is putting out 5 amps with the headlights on.

The horn should have power to one side all the time. Measure voltage at horn wires without pressing on switch. One side should have power. The horn button grounds the wire that does not have power when it is pressed.

See https://www.mafca.com/downloads/Seminars/2018 Reno Electrical System Alex Janke.pdf

 

[Rob Doe]

Neal, I'm confused. I'm thinking both sides of the horn should be hot until the horn button is pushed.

Smoked, this is an excellent riddle for a Saturday afternoon. Thanks for posting; where are you measuring the voltage at the headlights? Check the bulb filaments and both positions of the headlight switch. I cannot explain 11 volts on one side and 6+ on the other.

 

[nkaminar]

Rob, you are right. The wire will have to be removed from the horn to see which wire is hot and which wire goes to the horn button. Good thinking, 99.

 

[Rob Doe]

Smokey, do you have two ground cables? One from a cable at the bell housing or transmission and then to the frame at the x member where the battery strap connects?

As Neal suggested, clean and tighten the + positive battery post and strap and the ground at the frame x member connection. Clean, bright and tight. Grounds for the lights and the horn are via the headlight bucket, the light bar the fender bracket and the frame back to the positive post via the frame x member, unless you have a separate ground wire back to the radiator and then on to the frame.

The starter and ignition may be finding their ground path via a second ground cable from the bell housing. This would leave the lights and horn using the frame X member connection and then the ground strap.

 

[Smokedtires]

nkaminar thanks for the electrical link, that might very very helpful. Rob I know the battery positive goes to the cross member, i filed the frame when I put the battery back in this past spring. Not sure about a second ground going to the bellhousing/trans. Where would the 2nd ground go from the bellhousing if I were to install this?

I do have a fuse from generator to light/horn side of cutout that I noticed was blown when I 1st started trying to diagnosis this. Interesting about the horn wiring. If I can't find a hot wire there, maybe that's where I will need to focus.

 

[Rob Doe]

Smokey, if I understand you, you have an inline fuse between the cutout and the two wires, one of which powers the horn and one that powers the light switch at the bottom of the steering box?

If the above fuse was blown, there is a way that one of the head lights has shorted inside the bulb connector. Especially if the connectors are repro. Sixty years ago, on a date with my gal, I hit a hard bump and blew the headlight filaments in both lights. You are using incandescents? Quartz? Check the filaments for broken wires.

 

[Smokedtires]

I have LEDS in the headlights. Those, the cowl, and the brake lights don't work. Yes, I placed an inline fuse between the cutout and the lights/horn. I replaced the fuse, it hasn't blown again, and there is power to the headlights. When I checked for continuity at the wiring junction, for the horn, it was intact. I definitely don't have a second ground going to the transmission/bellhousing. The battery terminals are tight.

I feel it has to be a ground somewhere. When I checked the voltage at the headlights, I was checking the to pins at the end of the wires.

 

[nkaminar]

One way to run a ground to the engine is to run a cable from the ground on the frame to a bolt on the transmission or bell housing. You will need the type of cable that has ends for bolts and not the kind that connects to a battery. If you cannot find one at your automotive supply house, try a marine supply store or shop online.

 

[Smokedtires]

Well I traced it to the inline fuse holder. What I thought was 11 volts was actually 11mV so I was barely getting any power to the lights and horn. I decided to split the horn and light feeds to separate fuses for now. Currently everything is working again. I will look into adding another ground as well now. Thanks for the help, sometimes it just helps talking these things out.

 

[Rob Doe]

Nice job, I had a bad inline fuse holder in my turn signals fail just a couple months ago. Modern junk for sure. The insides fell apart.