Jump to content

Wiring question from new member

Recommended Posts

Hi! I just acquired a 1966 Avanti II (RQA-0090); the car was in storage for a number of years and has more that a few issues to work out, but I'm semi-retired and have the time and interest to pursue solutions. I've ordered shop manuals and have the car up on jack stands in the garage for assessment.


The issue I'm currently dealing with involves the wiring harness. A previous owner had installed a single-wire alternator, and although the car starts and drives, I noticed semi-melted insulation on the white-red tracer 12ga wire connected to the alternator. This, along with evidence of other wiring bodges, led me to inspect the engine compartment harness a bit closer. 

Whoa. I found the vinyl wrap to be burned through along several areas, including the sub-harness that leads to the starter relay. Quickly disconnected the battery, and started stripping the harness wrap. It appears that the white-red wire and plain red wire (both 12ga) both got pretty hot and melted through their insulation in many areas. Doesn't look like adjacent wires were damaged. While I don't have the factory wiring diagram in hand, a few links I've found indicate these wires run from the alternator to the ammeter (White/red) and back to the starter relay (red) and eventually to the + battery.

I've stripped back the harness wrap to the firewall and was astonished to find tape-wrapped splices on almost every wire in the harness, with some pretty creatively soldered splicing on the red/white wire. Plan to look under the dash and try to assess the condition of the wires all the way to the ammeter...will practice my yoga first. Really hoping to not have to pull the dash board, but that's probably inevitable. 

A few thoughts here:

First, how and why did this melt-down occur? My guess is that the alternator was initially mis-wired during "conversion" and cooked the wires. There's a 12ga plain white wire to ground at the alternator (ah, yes a fiberglass car!) and reversing those two would do the trick in short order. There's supposed to be a fusible link on the red wire at the starter relay that would burn out, but I don't see it. 

Second, hopefully, the damage was contained to the two wires under discussion, and I won't have to replace the entire harness (I ordered non-stick vinyl harness tape already). I'm hoping I can just replace the affected wires and re-wrap the harness. I've looked at a few posts in this forum and several people have just installed a new generic 24 circuit harness...rather not re-invent the wheel.

Third, is the "bundle o' splices" at the firewall really the way the factory built this car? The harness wrap at that point looked pretty original. I've owned many '60's era American cars and it's not uncommon to have a bulkhead multi-connector at this point to ease assembly and servicing, or just pull the whole harness through a big grommeted hole in the firewall. This is really amazing!

Great car, great forum, great people! I've wanted an Avanti ever since my dad declined my recommendation and bought a Riviera in 1963...wish he was still around to see this car!


Comments will be appreciated!



Marc in SF CA

Link to post
Share on other sites

I think I’ve figured how to upload pics, so here’s  two shots of the rats nest uncovered near the firewall. The pencil points to what I think may be fusible links spliced into the two burnt wires in question. If that’s what they are, I’m wondering why they are still intact with all the mayhem in the rest of the alternator-to-starter relay circuit.

if they’re NOT fusible links, what the heck are they?




Link to post
Share on other sites

Thanks for weighing in, Silverstude; repair splices may well be what they are. That’s some serious technique: the stranded wire ends appear to be wrapped in solid core wire and heavily soldered. An odd thing is that it’s only the two affected wires plus the white 12ga ground wire that have the extra wire, and it’s red insulation on the “added” wire on all three. That would be an poor place for fusible links, as it’s buried deep in the harness, rather than out in the open where they could be serviced.

I mentioned in my first post that the vinyl harness wrap in this area appeared to be pretty original....the nonstick tape was the same material as on the rest of the harness, the weathering/dirt/crud was no different and the tape wrapping itself looked untouched. If this is a repair, it was done a long time ago and the entire harness section was rewrapped by a pro!

I sure don’t expect anyone to cut open their wiring harness to see if this is normal, but I wonder if anyone else has knowledge of the factory wiring procedure.



Link to post
Share on other sites

I don't know if I can help but let me add some thoughts. 

Fusible links are usually a smaller diameter wire in-line so a short will melt that section. In my experience from this era, fusible links on Chevy/SBC applications are usually in-line and attached to the lug on the starter solenoid that the alternator and fuse box feed wire attach to. 

I assume when you have driven the car some miles so it's not clear if you are finding any of the wires get hot or are just nervous about it because of the mess you found. If the wires are cool it might be worthwhile to just rewire the area you found with wire of the same gauge as the main wires and be sure the fusible links exist on the starter.

The wiring you show is certainly cludgy but not a bad attempt at repair. Soldering connections is the appropriate way to join wire but a couple of the joints look like a cold solder so I'd replace them all. Get a good high wattage soldering iron for the job and electrical grade solder.

In my experience,  wires usually melt close to the source of the problem so in your case, it could have been that during the po install a couple of wires touched in the bundle and caused this problem. I'd be sure to check under the dash to see if this problem has appeared there.

I don't know enough about your year car to know if it had a voltage regulator. If so, I'm over my pay grade. If not then the one wire should be a direct replacement.

Edited by Avanti83
Link to post
Share on other sites

Thanks, Avanti83.

To clarify, “starts and drives” refers to starting the engine and driving the car off the trailer into the garage. The car was in storage for several years, and brakes are next on the repair list!

i believe the car originally had a voltage regulator and was converted to single wire by a PO (Previous Owner); there’s a receipt for a new alternator in the file included with the car. I’d mentioned other electrical bodges...there’s an unused multi-wire connector near the battery that was most likely the voltage regulator location.

Here’s more pics showing an overview of the harness (the looped wire separated from the rest is the white-red to the alternator), a section of damaged harness before dissection, and the firewall bundle ‘o splices just after unwrapping.

The under dash wiring looks ok, so hopefully I can re-wire from the firewall splices. I’ll be sure to include a new fusible link at the starter relay, and maybe at the alternator post as well. Repairing vintage tube guitar amplifiers is another hobby for me; I’ve got a good iron and rosin-core solder. Good call on the cold solder joints, by the way.

I’ll also plan to test the repair BEFORE re-wrapping the harness!





Edited by MarcD
autofill substituted "bridges" for "bodges" in original post
Link to post
Share on other sites

The burning on the white, red traced wire looks like exhaust manifold damage.

A couple more thoughts. 

You should also join the SDC site. Way more members than here and also helpful.

There is a young man there that just purchased a 67 Avanti totally restored. He also works for Stephan Allen Studebaker parts in Florida. His name is Matt Burnette (mbstude - member name). I can't tell from his pictures what he has for an alternator setup but he might be worth a PM to get further pictures and assistance. His post on the SDC forum. http://forum.studebakerdriversclub.com/showthread.php?106248-67-Avanti Tell him sweetolbob sent you. I've posted a fair number of improvements and modifications to my 74 and 83 over there and linked to this site.

Bob Johnstone has a great site of Studebaker and Avanti knowledge. The problem is when Newman and Altman took over and went to SBC's, little was documented on the conversion and upgrades. Bob has some documented wiring changes but not all. These probably won't add much but will serve as an intro to his sight. There is a wealth of knowledge on all things Avanti there. Be sure to explore the site in depth.


These are great looking and driving cars when setup correctly but it takes a bit of study and perseverance to get there. Don't ask me how I know.

You mentioned brakes. If your's need a complete replacement there are a couple of newer alternatives that replace the older parts with ones available at local auto parts stores. One is Turner Brake. http://www.turnerbrake.com/ I have those on my 74.

Lastly, because the SBC's are generally from the same or previous model years as the Avanti's, their engine manual and engine bay wiring diagrams could be of some help in the future.

Welcome, Bob


Edited by Avanti83
Link to post
Share on other sites

The wiring schematics seemed to change often during the Avanti II years...different alternators and locations...separate voltage regulators and then alternators with internal regulators...different a/c compressors...location changes for switches, etc.  Avanti Motors made their own wiring harnesses in house as needed.  

If you feel the need, you can find NOS wiring harnesses for a particular year (maybe) from some of the Avanti vendors...Nostalgic Motors or Dave Thibeault come to mind.  If you go that way you'll still have to make some modifications since a one-wire alternator has been installed.  It's a fair amount of effort involved but you'll know you'll have good wiring.  

One other option is to buy a universal wiring harness from Painless Wiring or Summit Racing...they sell 12- an 18-circuit harnesses and it's all with modern plug-in fuses.  Again...a bit of work but a good way to go.

Link to post
Share on other sites

As above, welcome.  These cars are, indeed, a joy.  I have a '66 (0108) and, as you, had fried wiring when I got it -- from your description, the same wires.  Like you, the instant I discovered it, the battery was immediately disconnected.  Mine came with the one wire set up; the regulator is mounted under the dash below the fuse block -- I retained that setup.  I had insulation melted and hanging under the dash and under the hood.  Not knowing how it looked inside the bundle, I decided to replace those wires and they had melted insulation all inside the bundle.  The Reader's Digest version is that I took down the dash and ran new wiring through the bundle.  I took this opportunity to do several things with the dash out:  change the defroster hoses (rotted and full of holes) and the hoses running from the cowling to the transmission tunnel (same), put in relays to control the lights, make new ventilation 'doors' (about as much air leaking as being blocked), etc.  If you decide to take your dash down, be sure to label everything.  It is not an easy task but it is certainly do-able.  Just do some thinking and reading about what you might want to do and do it all at once.  I wrote an article in one of the AOAI magazines which has several things listed regarding what I did.  I'm not at home right now but will find out in a couple of days what issue it's in and edit this post to include that info.

As per above, I'd strongly suggest the Turner brake system, at least for the front.  I'd suggest putting in a fuel shutoff solenoid; the procedure, and why to do it, is addressed in the article.  I'd also suggest a Ford type starter solenoid set up.  These SBC motors apparently had solenoid problems in that, often when hot, you hear a clicking but the starter does not engage; the 'Ford' set up cures that.  Summit racing sells that setup as a kit, or at least they did a couple of years ago, for $20.00 which is probably cheaper than you can buy the individual parts (solenoid, heavy jumper wire, jumper clip, ...).  I submitted another article regarding this; I'll find that issue number also.  I wrote another article regarding exhaust odor; I'll find that one also.  Succinctly, mine had a hole in the heat riser which, apparently originally, had a tube which led to the choke to conduct heat from the exhaust to control the choke.  Plugging that hole quieted down the noise and removed almost all the exhaust odor when riding down the road.

I had a 700R4 GM transmission put in mine; they originally had the Borg Warner 3 speed which is, of course, one to one in high gear.  The GM transmission has a torque converter lockup and an overdrive.  Mine has the 3.07 differential and the GM lowered the rpm's at 70mph from about 3100 to 2200, or so.  Saves the engine, better gas mileage, and you can talk with someone riding with you.  The cars are certainly light enough and the engine strong enough to handle the overdrive.

I'll edit this post in a couple of days to point out the articles.

Again, welcome.


Link to post
Share on other sites

Thanks for the info and warm welcome, Bob!

Small world; I ordered manuals from Stephan Allan last week and the very helpful and knowledgeable young man on the phone was...Matt! Nice to see the flame being carried forward; I had to practically drag my kids to the DMV to even get them to drive!

RE: the white-red wire damage; that wire was completely encased within the harness and not in contact with the manifold. The damage you see must be entirely caused by shorting!

Thanks again for the forum tips; I’ll follow up and keep expanding my knowledge base and hopefully contribute from my past mistakes..uh, experiences.




Link to post
Share on other sites

Hi Mel


Thank you as well for the welcome and tips; I’m already in process of installing the Turner Brake kit, and will certainly ponder long and hard before diving into the dash.

Looking forward to reading your magazine articles. My PO is a great guy and included dozens of back issues with the car, and the manuals arrived from Stephan Allen today...lots of study ahead!




Link to post
Share on other sites

Hi Marc,

Rather than edit the previous post, I'll just add another.

The article regarding the headlight relays, kick panel vent doors, headlight reminder circuit, etc., is in issue 170, page 47.  (I'll suggest checking the vent doors as my factory doors had basically disintegrated and they leaked tons of air.)

The article regarding the 'Ford' type solenoid set up is in issue 174, page 7.  Very easy to install.

The article regarding the exhaust leak is in issue 175, page 35.

If you decide to take the dash down, the service manual has the procedure laid out.  There is an article in issue 82, page 38, which the guy says is easier than the procedure as laid out in the manual.  Might be easier; I found it after I'd done the job.

You can get back issues of all the magazines on disc; some good info.  They're pdf's but, again, some good info.  If you can get a copy of the '2018/2019 Membership Roster' from AOAI, that publication has not only the roster of all members (by state, by serial #, and owner alphabetic listing), it also has an index of all the articles written in all AOAI magazines.

Keep us posted and be sure to post any questions.  This is a great community and folks are great about providing answers, experience and moral support.

Good luck,


Edited by Mel
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...