[Peter Serio]

This is more a question directed to electrical guru george kujanski but anyone is more than welcome to chime in as well.


Here is the deal: I am rewiring my last convertible: '63 Lemans 326 V8 engine 2 speed transaxle. I untaped the original V8 engine harness only to find it badly melted, (see photos). Seems the main power supply wires running to and from the amp gauge got very hot. More than 1/2 of the run (Brown wire) starting at the dash harness all the way to the hot lug on the back of the old alternator is completely fried.

My plan is to upgrade this car to a modern 63 amp 10 SI alternator as well as doing away with the amp gauge altogether. I am going to install a "gen" light and possibly a volt gauge instead.

My question is this: I have noticed that nowhere in the original engine compartment are there any fusible links, was this a cost saving measure ?

Should I add in one or 2 as a safety measure as I am replacing most of the main power supply feed wires anyway. Where would be the best place to put them? At the 12 volt "+" function block on the driver's side fenderwell or at the output on the rear of the new alternator? I am going to do away with the yellow wire that runs from the rear of the old amp gauge to the junction block and simply run the 14.2 volt output wire from the new 10 SI over to the junction block on the fenderwell. This is how most modern (1980s era) GM cars are wired, does this sound about right to you?

[Old Goat 67]

Wow, you got a mess there Peter!

George will be the best for questions about the alternator, so I'll leave that alone for him to get here. I tried PM'ing him lately, but his box is full.

If it were me, I believe I'd put in a circuit breaker on the fender well, like they did on my 67 with power window or seats or convertible top motors. Rather than burn out, they will reset. Just a thought.

Charles

[Peter Serio]

I posted the worst photos first, I have another pretty clean harness that is in a lot better condition. Basically this one is good for parts.

I checked at M&H & they get $459 for a "new" 63 Lemans dash harness. When compared to the next model year GTO, you are actually getting 3 harnesses in one. The dash/fuse block, engine compartment and the front headlamp harness are all made into one on all 63 Tempest and Lemans cars. For 1964 they are all three separate. And they plug together at the firewall.


If you want M&H to build you a new one for a '63 (I called them) they request that I send in my old one, I asked what they wanted off of it. And they said "we need the plastic fuse block and the black plug that goes on the back of the ignition switch." + There is a 4 to 6 week wait.

[george kujanski]

I emptied out my inbox recently. Peter, I'll look at it later today when I have some time.

Later.

george

[HWYSTR455]

When it comes to fuse-able links, they're supposed to be as close to the accessory the wire is feeding, in general. Better= one for EACH accessory. Yes, breakers can be useful, though in certain high-load situation, they can 'cycle' too.

MAD has several tech articles that address several areas, as well as by-passing a factory ammeter.

http://www.madelectrical.com/electrical-tech.shtml

The MAD tech stuff is a great basic source of info, and even if you don't use the suggestions, worth a read. I suggest getting the concept of the 'power-up' advice clear, will help when looking at either upgrading or fixing any car electrical system.

If doing an engine harness, always upgrade the alt charge wire to a larger gauge, for future needs if not current needs (no pun intended!).

If you're looking at doing extensive repairs, you may consider a 'kit' from some place, like American Auto Wire. You get an updated fuse block (for one), and could save you time overall. (now or in the future troubleshooting).

If you're not going for the factory look, the woven expandable loom (covering) is great stuff, and looks even better than it works.


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["QUICK-SILVER"]

Since it is an 'up-grade'.

First; I think I'm starting to like the big maxi fuses better than fuse link wire. If nothing but for the ease of changing them compared to doing fuse link correctly. Sure is easy to carry spare fuses as opposed to carrying spare link, soldering iron, etc.

2: Junction block for power supply is the only way to go. I like un-cluttering engine wiring as much as possible. Especially when fuse link is used. Forget those days of having to go to the starter solenoid or undoing wiring harness behind the alternator to repair a fuse link.

3: Replace wire but use the original power supply wire locations going inside. Both engine running/alt charging (main splice under dash), and the orignal engine off/no charge junction block wire. Just splice the two together where the old amp guage connections were at. That may be overkill but is bound to last for ever.

Simplier the better. Cleaner and neater. No extra wires on a hot engine.

[HWYSTR455]

Originally Posted by "QUICK-SILVER"

Since it is an 'up-grade'.

First; I think I'm starting to like the big maxi fuses better than fuse link wire....

2: Junction block for power supply is the only way to go......

3: Replace wire but use the original power supply wire locations going inside....

Simplier the better. Cleaner and neater. No extra wires on a hot engine.

That's what I did, all three, and then some. I used a ford sol as one junction block, or the main junction block, mounted above the factory bulkhead harness connector, and grouped all the power wires from the bulkhead connector to it. Also the alt charge wire, the starter wire, the wire that goes to the battery, a 2GA wire that passes into the passenger compartment with a maxi fuse in between, and another 6GA wire that goes to a fuse block on the radiator support.

The one 6GA that goes to a 6 fuse ATC/ATO block on the radiator core support I have a bank of relays off of, 2 for the fans, 2 for the headlights, and 1 for the horns.

The 2GA that goes into the passenger compartment I have a stud mounted under the dash, off that stud I have 2 4 fuse ATO/ATC block, one fuse block I have a 40amp relay that is key-on, the other full time, for under-dash accessories.

On that same stud, I go back to the trunk with a 2GA to another stud, and a 6 fuse ATC/ATO block, with a bank of relays. Those relays feed the fuel pump, N2O bottle valve, N2O bottle heater, and have spares. I feed a pair of stereo amps from the stud (they have built in fuses).

This setup provides full power to all the studs with very little drop, even with all accessories on. Also allows for easy addition of accessories, and easy troubleshooting too.

All the terminals for factory harnesses are available, so you can pop a terminal out of a connector, re-do it (even with heavier gauge), and plug it back into the connector.

Think I posted pics here somewhere, at least of sections of it, if you're interested in searching.


.

[george kujanski]

here's a quick sketch of what you can do.

The idea of using modern fuses such as the Maxi-fuse instead of links is good for the mentioned reasons. A junction block keeps the mess of cables away from the starter large bolt, which was used as a handy junction point.

Since you are not using the ammeter, you can use the existing brown wire from the alt to the junction block, and the yellow from the block, thru the fuse, to the main feed to the car.

The two fuses protect against an alt cable short and a short on the main feed to the car. As always, there's no fusible protection from the bat to the starter; that would need a 400+ A fuse.

George

[HWYSTR455]

That's pretty much what I did George, except instead of a junction block, I used a ford sol. Guess I could clean that up a little and use a junction block, will go back over it since I want to use the expandable loom stuff (mine's wrapped at the moment).

Oh, and by the way, there are pics on my photo album of the wiring on the driver, though some a little dated.

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[Peter Serio]

I like the idea of getting away from the starter for a junction, the only wire I see that needs to go there is the batt cable and the purple for sol. (Thanks for the diagram George.)


Could anyone post a photo of their fenderwell mounting junction block using those modern maxi-fuses to give me an idea of what I am looking for. Can those be sourced out of any modern car(s) in the junkyard? Ford? GM?


I read all of the MADelectrical tech articles.

I like the part on MAD about running the #2 wire to a point closer to the "branch" perhaps underneath the dash on my harness. I see a big splice that I think I can get to. 25 years ago I had a red 63 convertible and I put 10 SI alt s. on that. It gave me headlights that were a LOT brighter! In the old days we used to just loop the #2 wire right over to the big stud on the back! And then jumper the 2 wires that plugged into the old VR. I don't recall adding or having a "gen" light back then. As I recall I had to rev the engine up a little to get it to start charging. lol.

[HWYSTR455]

You don't need the purple wire to the starter, jump it to the pos cable post, and use a remote sol, like the hot-start fix does.

Junction block, there are many to choose from, and if you really wanted to get trick, you could use a modular fuse block that incorps maxi, ATC/ATO, mini, and relays, all in one. The basic stud type is what I think you would be best with.

Source, again, many out there, here's some of who I use:

http://www.delcity.net/

http://www.wiringproducts.com/

http://terminalsupplyco.com

http://www.trickcableandswitch.com

http://www.techflex.com/ (expandable loom I mentioned)

As for the splice under the dash, replace it with a stud type distribution block, will give you more flexibility.

Attached are some of the pics from my stuff over the years, might give you some ideas.

Another suggestion, if you're going to upgrade to an internal alt, use a CS130, or better yet, a CS144.

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