Is there a fuse or fuse able link here.

I installed a new steering wheel this weekend on my 67 cj5 w f134. While the steering shaft was open it was also time to install a horn as one of the po's had gotten rid of it. Got the wheel and horn kit from kaiserwillys and all went together well. The wiring diagram shows a 10amp fuse able link on the power wire coming from the ignition switch. I can't find a link in this mess of wires so my questions:
1. Is there a way to test the wire/circuit to determine if a link is there?
2. Is there any harm in installing an in line fuse even if a link is there that I can't find?
3. The horn works fine. Is that evidence a fuse may be there somewhere ?
Thanks guys

 

The short answers --
1.) Yes
2.) No
3.) No

 

Ok thanks. Can you describe how I can test to see if there is a fuse/link there? Appreciate it.

 

Sorry, my late-in-the-day short answer to your question#1 was in part a late-in-the-day test you don't want-- apply amperage that the wire will handle, but will blow the link.

Seriously, if you were a studied electrician/electronics person, and it was life-or-death you could test and come to a conclusion, but your question #2 is the way to go--get a known fuse in the line.

Disclaimer: If you have any uncertainty about proper fuse protection or wire quality, replace it--
The saying goes something like--To limit your losses, if you're not properly fuse-protected, take the Jeep out of the garage where you can control the burn--and burn it!

 

Ok. Option #2 it is, Thanks. She's not very pretty but she's all I got. Don't want to burn!

 

Good point. Bill nothing beats tearing it apart... (I'll stop!)

 

Thanks both Focker and Dave! Looks like I've got a short term fix and a longer term project opportunity. Love working on this old thing so it will help keep me busy.

 

late to party . horn gets its power from circuit breaker on headlight switch , wire to horn button is just a ground , no need for a fuse there

 

That's true if stock. I didn't read and re-read the OP well enough. Likely he is stock, as he refers to a diagram with the inline fuse between headlight switch and ignition switch.

 

Just a comment on this.

Focker's work is outstanding, but I'd like to point out that adding a lot of extra wire increases its vulnerability to failure. The factory Jeep harness is very minimal, and only the wires upstream of the fuses are unprotected. To me, it makes sense to keep those upstream runs as short as possible, and to protect those upstream wires as much as possible.

To me, fuses are like insurance - you hope to never use it. Having them inline with the harness does not seem like much of a burden considering that my efforts should be directed at making sure I never have to access them.

So, I think you can either 1) accept the original minimalist concept with short wires and just a few strategic fuses or 2) take the modern approach that puts all the fuses in a panel, and resorts to dozens of fused circuits to divide the functions among many accessible circuits.

My focus would be on protecting the wires. A short due to abrasion with the body panels or hot engine components would be my central concern.

 

Along these same lines, I need to put a fusible link in my main 12-volt line. What value is normally found in early CJ-5's? I have a 35 amp Motorcraft alternator if that really even matters...

 

Early CJ5's did not use a fusible link. However many cars (Dodge for example) had a fusible link that was about 4 inches long.

 

Looking at the various TSMs, it seems Jeep did not start equipping the CJ with fusible links until they started using an under-dash fuse panel, ie 1975.

If you look here http://oljeep.com/gw/76_tsm/Section22.pdf you can see the fusible link that protects the alternator charging wire and the power wire that goes under the dash, between splices G and H. Wire gauge gives you an indication of what size link to use - Catalog Note that the 10 ga wire goes to splice P and fans out to feed several devices.

My understanding is the fusible link is simply a last resort - it's there to prevent a car fire in the event of a catastrophe, like a major collision. My feeling is that those small-gauge under-dash feeder wires are still going to end up melted if they need short protection.

 

Tim, I hear what you are saying, but I once had a Vega a long time ago, and the main battery cable (Positive, of course) somehow became shorted to ground. I don't remember exactly how, since it was long ago. I didn't have a fusible link in line and it was not pretty. Took out the battery and the alternator. I installed an in-line link after that happened.

I agree 100% that if anything shorts downstream of the fuse panel and it is not protected correctly, the small AWG wires are going to become a fusible link on their own. Have a good weekend. I will be bouncing around town in my Jeep. Need to get it off-road, but my schedule is not allowing me much time for that right now.