My Willys 3A and 3B Community

3A, 3B, DJ Technical Knowledge Base => "Original"-- Technical Questions, Answers, Observations => Topic started by: bayo500 on November 11, 2010, 06:09:14 AM

Title: No fuses ?
Post by: bayo500 on November 11, 2010, 06:09:14 AM
Hi, I'm rewiring my cj3a using a wiring diagram off the previous site. My question is the breaker on the end of the h/l switch, is that all the system needs ?  (I'm keeping it at 6 volt) Thanks...
Title: Re: No fuses ?
Post by: Carls_jeep on November 11, 2010, 08:17:11 AM
That is all the original system had but I plan to put a fuse block on mine when I get around to it. I rewired mine when I bought it but I didn't use the wiring diagram exactly. The thing is they have worked that way since the first Jeep with little trouble soooo, if it ain't broke don't fix it.

OTOH, I do like the idea of fused circuits.
Title: Re: No fuses ?
Post by: mud pie on November 12, 2010, 08:29:05 PM
Fuses ? Then you can't play "find the fuse box, and I'll give you 50 bucks" with anyone !
Title: Re: No fuses ?
Post by: Doug on November 12, 2010, 10:03:18 PM
The headlight switch has an automatic circuit breaker.   However, only certain components (those that draw their power through the headlight switch junction board, are then breakered.  Mainly the headlight, tail lights, and I think horn and possibly the ignition are protected.    Other components such as ammeter, and other wires, really have no circuit overload protection at all.  If one of those was to short, say to the dash board from a loose wire, it would just continue to short until something burned through.   To avoid that unpleasant scenario, I varied from the original design by adding a "fusible link" as a fail safe where the main wire supply comes off the starter and feeds the ammeter on the dash.  A fusible link is used on more modern cars even with fuses.  It's the circuit breaker or fuse of last resort and cuts all power to the jeep.    That way if there is a short to the dash say from an ammeter wire, the fusible link could burn through and cut the electrical supply.  A fusible link is available for about $3 and is merely a piece of short wire that has a rated capacity before it burns through.  Just my suggestion.    Without a fusible link, if there were a short, the only way to stop it would be to disconnect the battery cable.  Not a fun task when the sparks are flying and wires sizzling.  
Title: Re: No fuses ?
Post by: bayo500 on November 18, 2010, 12:34:23 AM
Thanks, I'll go with a hidden fusable link.
Title: Re: No fuses ?
Post by: Harald on March 18, 2017, 07:13:10 PM
I think when rebuilding mine, I'll have it a fuse box. Unorthodox, but that's ok with me. Safety first. Especially since the engine does not run on diesel (which would be less inflammable.) 8-)