Horn and Head Light are Causing Problems (Electrical) Please Help!

1945 - 196*, Willys CJ series, questions, discussions, regarding anything related to the post war jeep.®
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elimark1
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Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by elimark1 » Mon Mar 29, 2021 6:33 am

Hello Everyone!

I recently purchased a 1948 WIllys CJ2A...

I tried installing a 6Volt horn yesterday and ran into some problems (Before the install,

I tested the live wire to the horn and it was good) First off,

I made a rookie mistake by not unplugging the NEGATIVE battery cable (Big Mistake) and when I went to tighten down the live wire to the horn,

I created a couple of sparks.

I got sound out of the horn initially and now I don't get any sound and as a result of my carelessness,

my headlights aren't working now.

I'm sure I shorted out the live wire! Since there are no fuses,

I tried re-setting the circuit breaker by unplugging the battery cables and still the horn and lights don't work.

Is there another solution to this problem?

Is it possible I shorted out the horn?

Do you think I have to replace the light switch?

I'm embarrassed by this mistake,

but as you can see,

I'm very new to this hobby.

If anyone has any suggestions/advice please help me out! I would really APPRECIATE it!!!

Thanks,
Eli

P.S. I just tested the hot wire to the horn and I'm getting 6 volts, so I guess I didn't short out that wire...The horn must be bad! Still no headlights though


Bruce W
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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by Bruce W » Mon Mar 29, 2021 10:17 am

There are HUNDREDS of possible defects that could cause your problems. 73 years of age, weather, rodents, insects, and Bubba have taken their toll on most of our electrical systems. There is only one circuit breaker in the jeep originally, on the headlight switch, and the horn does not get its current from there. The breaker is (was?) self-resetting without you having to do anything.
Let’s go on with the horn, maybe we’ll stumble onto the headlight problem along the way. The horn has current to it, at one of the connections, all of the time. There is no relay, fuse, breaker, switch, etc on the hot side. You say you have 6V to that one wire connection, so let’s move on to the other side of the circuit. The wire that connects to the other terminal on the horn goes to the horn button on the steering wheel, where the circuit is grounded, completing the circuit. Connect a jumper wire from that second connector (the “cold” one) and ground the other end of it. If the horn honks, the wire from there to the horn button is at fault somewhere. If it doesn’t honk, the horn is bad or, possibly the battery is discharged. The horn takes a lot of amperage to make it work and if the battery is low, it may not honk. Back to the horn wire. On a ‘48, there are two possible routes for the wire to get to the button. Early ‘48’s have a brush mounted on the top of the steering column mast jacket just above the gear box that contacts a brass ring on the shaft inside. The wire from the horn connects to that brush, then there’s a wire soldered to the brass ring and runs through a hole in the shaft and up to the button. A very troublesome system with lots of places for lost continuity. Later ‘48’s have a hole in the bottom of the steering gear box and a wire runs through it directly to the button. Better but still not great.
Everything I say pertains to the horn circuit as it was produced in an original 1948 Willys-Overland universal jeep. There may be differences in yours, thanks to our old friend Bubba.
Try the jumper wire trick and look the rest of the circuit over, and let us know what you find.
BW
G Trp 2nd Sqdrn 3d Armored Cavalry Ft. Lewis 1970-71. 43GPW(Sarge?) 47CJ2A(Teddy) 47CJ2A(Rusty) 47CJ2A(Zak) 48CJ2A(Lefty) 48CJ2A(Uncle Linden) 53CJ3B(Bulldog) 88XJ(Pluto) NE CO

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by Wolfman » Wed Mar 31, 2021 6:57 am

Bruce covered the horn nicely.
The lights.
CJ lighting system is much simpler than the military counter part. No Black Out circuits.
Power comes from the amp gauge to the light switch.
The light switch has park & service positions.
In park, the power goes to the tail lights, if you have them and the front parking lights. The head light wire goes to the dimmer switch, on the floor board and from there to the head lights.
Just a matter of checking where you have power and where you don't.
If you have power into a component but nothing out, you found the problem.
Mike Wolford
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Comm./Inst. SEL
AOPA ( 50 yrs)
EAA ( 49 yrs)
4th Inf. Div. - 5th Inf. Div. - 2nd Armor Div. - CIB

gpw4738
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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by gpw4738 » Fri Apr 23, 2021 5:15 pm

Have you checked the fuse on the headlight switch?

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by Bruce W » Sat Apr 24, 2021 8:21 am

gpw4738 wrote:
Fri Apr 23, 2021 5:15 pm
Have you checked the fuse on the headlight switch?
There is no fuse on the headlight switch.
BW
G Trp 2nd Sqdrn 3d Armored Cavalry Ft. Lewis 1970-71. 43GPW(Sarge?) 47CJ2A(Teddy) 47CJ2A(Rusty) 47CJ2A(Zak) 48CJ2A(Lefty) 48CJ2A(Uncle Linden) 53CJ3B(Bulldog) 88XJ(Pluto) NE CO

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by gpw4738 » Sat Apr 24, 2021 9:08 am

Must not have the oe. Switch, all my Cjs have a fuse on the switch. Just a suggestion

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by Bruce W » Sat Apr 24, 2021 11:06 am

All of my CJ’s (8 of them) and all of my spare switches have circuit breakers on them.
BW
G Trp 2nd Sqdrn 3d Armored Cavalry Ft. Lewis 1970-71. 43GPW(Sarge?) 47CJ2A(Teddy) 47CJ2A(Rusty) 47CJ2A(Zak) 48CJ2A(Lefty) 48CJ2A(Uncle Linden) 53CJ3B(Bulldog) 88XJ(Pluto) NE CO

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by 85jeepcj » Sat Apr 24, 2021 11:51 am

Follow the positive horn wire until you find a live connection.
Wiring diagrams on Google but in 70 plus years many changes can happen.could be a unconventional fuse someone installed.
Original factory wiring the horn and the lights get powder at the amp gauge, the fuse on the light switch doesn’t power the horn.

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Re: Horn and Head Light are Causing Problems (Electrical) Please Help!

Post by dpcd67 » Sat Apr 24, 2021 4:37 pm

First post; welcome to the forum. I recommend you take a step back and resist the urge to dive into your new jeep any more until you have obtained some manuals and studied them for a few weeks and understand the system you bought; get the Jeep Universal manual, and even reading TMs for military jeeps will help a lot with the basics.
You might have done that, but I see this all the time; new owners can't wait and then damage something.
No substitute for studying the TMs; I do it every day.
U. S. Army 28 years.
Armor Branch


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