M38 horn - help needed

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TonyMorreale
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M38 horn - help needed

Post by TonyMorreale »

1952 M38, 24v with circuit breakers on the side of the cowl battery box. New complete wiring harness installed last year. Jeep runs, lights work, etc. No horn on jeep, or horn wiring when purchased.

Tonight I installed a new horn, horn switch, and the rod that goes up the steering column to the nut/button. I connected the #25 wire behind the dash to the breaker on the batt box per the manual and wiring diagrams. Horn is properly grounded to fender.

Here's where I'm baffled. On the new harness I installed I've got three #25 wires in the engine compartment. Two are close to the firewall and one is near the front of the jeep where the blackout light would be (I don't have one of those either). I tried hooking up the wire from the horn switch to each of the #25's near the firewall and cannot get the horn to sound at all so I can't adjust and lock the switch in place in the steering box.

From reading the wiring diagram, it's my understanding that the #25 wire should run from the breaker to the switch then the wire from the switch runs to the horn and the horn to ground. The diagrams I'm looking at only show one #25 wire in the engine compartment associated with the horn.

Do I have it wired backwards somehow? Is it possible that I've got the wrong switch wire going to the horn and connecting to the #25 respectively (I thought it didn't matter which went where)?

Am I missing a wire that should connect to one of the other #25s in the engine compartment?

Any help is appreciated - thanks!
Tony Morreale
Franklin, TN
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wesk
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Post by wesk »

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Tony,
Yes you have three #25's at the left fender. The two pig tails from the switch, the long wire coming down from the circuit breaker. They are all #25's.

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You hook the long wire from the CB to either of the switch pig tails and hook the other switch pig tail to the horn.

As I read your description of your harness it sounds like you have the switch hanging on the steering box with two #25 leads but it also sounds like you have three more # 25's in the harness with two of them near the firewall and one up forward on the fender. That sounds like a boogered up harness. Is it possible you are confusing the #75 wires for the brake switch as being # 25's? If this is the case ignore my following comments and hook the 25 near the front to one of the switch leads and the other switch lead to the horn.

A few things for you to check:
1-Does the #25 up front have a connector that will fit on the horn's ground terminal? When you ohm out that wire is it grounded to the fender?

2-Check for system voltage at each of the two #25's near the firewall. Do this both master switch on and off.
Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100

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TonyMorreale
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Problem solved.

Post by TonyMorreale »

Got the horn squared away this morning (in my frustration last night I had over adjusted the nut at the horn botton allowing the rod to engage the switch, but not fully). Arrrghhhh.

I still have the mystery #25 wire (tagged at both ends) that runs the length of the left front fender (beginning near the firewall and ending near the grill) but shorter than the #19 BO light wire. I suppose as Wes says this is simply an extra wire accidentally added to a "boogered" harness...
Tony Morreale
Franklin, TN
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