Upgrading to 60 amp alternator - wiring changes per Factory Service Manual

[cuda346pk]

Ok, alternator is dying so time to replace. Got a 60 amp Bosch from Napa. In looking over the service manual wiring diagram I noticed they show the optional wiring if the car came factory with a 60 amp. They run the ammeter wires straight through the firewall bypassing the bulkhead, which is of course recommended. My plan, looking at the diagram attached, is to run a 14 ga fusible link from the starter relay, marked in orange, to 8 ga red with no splices through firewall to ammeter. Disconnect the original dark blue 16 ga, fusible link and 10 ga red to bulkhead and ammeter, marked in green. Replace black 12 ga from alternator output with 8 ga black, splice 10 ga black at splice #2, continue 8 ga through firewall to ammeter. Take 10 ga from splice through 16 ga fusible link, and splice to original 12 ga black going through bulkhead at #18 to power the gauges - all marked in black. I want to keep my ammeter in the rallye dash, I have gone through and cleaned all connections and made sure all was tight when I rebuilt dash recently. My question is: looking at the diagram, the alternator field connection j2-18dbl goes to splice #1 with small alternator and j2f-18dbl to fast idle solenoid, which I do not have. The optional wiring for the 60 amp shows j2f-dbl running to #1 splice instead of j2d-18dbl. Doesn't seem to make sense to me, I would think just leave that wired as is. This is in yellow highlighter. I would rather keep my ammeter as opposed to running jumper straight to the starter relay and have to add an aftermarket volt meter.

[Chryco Psycho]

so why not just run a jumper in 8 or 10 ga from the alt output across to the start relay terminal & be done with it , your ammeter will still deflect a little with the load to the ign etc

[cuda346pk]

so why not just run a jumper in 8 or 10 ga from the alt output across to the start relay terminal & be done with it , your ammeter will still deflect a little with the load to the ign etc

I thought the ammeter became basically worthless when you ran the jumper? Would I just leave the remainder of the wiring as it is? I.E. 12 ga black running through #18 at bulkhead.

[cuda346pk]

Ok I found some more details in the threads about the ammeter with using the jumper. So if I go this route the ammeter will still function, just not as accurately as factory? It seems as long as I am smarter than the average bear I will be able to still monitor my charging once I see some of the range it has and get used to it. That correct? This is certainly a much easier and less time consuming route, plus sourcing the 8 ga wire and connectors locally seems to be a problem. I will install the new alternator and regulator, run it with wiring as it is now, then add the jumper and have a good starting point to see on the gauge. Is a single 10 ga wire enough for the jumper or should I double it up?

[Chryco Psycho]

makes sense to me , the ammeter will still have some load across it

[422STROKER]

Try a basic amplifier kit for the 8ga wiring and ends.  Comes with fuseholders etc as well.

Tom

[cuda346pk]

Try a basic amplifier kit for the 8ga wiring and ends.  Comes with fuseholders etc as well.

Tom

Good idea. What a difference a little waiting can mean, either I can go to Best Buy locally and pay $70 for a Kicker 8 AWG install kit or order through Amazon for $18 + $10 shipping. Glad I have the time to wait on that - awful big difference for an identical part. Now should I use the 50 amp AFS fuse that is included or get a 12 Gauge fusible link? Plus do I put whichever one I use at the starter relay end or alternator end of wire?

[422STROKER]

I used it at the battery end, but it's a guess which end is better.  I think I put a 60A in mine.  Odds are that wire never sees 60 A but if it does then there's an issue.  I bought it at Walmart fwiw, Scosche brand I think.

Tom

[cuda346pk]

I used it at the battery end, but it's a guess which end is better.  I think I put a 60A in mine.  Odds are that wire never sees 60 A but if it does then there's an issue.  I bought it at Walmart fwiw, Scosche brand I think.

Tom

Are the fuses as effective as the fusible links since the links will handle quick shorts like accidental grounding of a wrench or other oops moments. The fuse will be easier to use as it is coming witht he kit but I would have to find and get a 12 ga fusible link, no one seems to have them in stock around here.

[asm74]

I'd like to do this in my 73 as well, but would like to do it without permanent harness damage.  Does anyone have pictures of how they routed the new wire?

[cuda346pk]

I'd like to do this in my 73 as well, but would like to do it without permanent harness damage.  Does anyone have pictures of how they routed the new wire?

I simply ran with the current alternator wires to firewall then across to bulkhead then picked up the headlight and assorted wiring to attach to and ran to the solenoid. I just taped mine to the harness but you could zip tie no problem too. Did not cut the original harness anywhere. Great upgrade and even though I see no fluctuation on the meter I think I will still quickly see if the alternator dies by the meter. Also did the headlight relays at the same time and wow what a difference together.

[422STROKER]

Are the fuses as effective as the fusible links since the links will handle quick shorts like accidental grounding of a wrench or other oops moments. The fuse will be easier to use as it is coming witht he kit but I would have to find and get a 12 ga fusible link, no one seems to have them in stock around here.

Do new cars use fusible links?  You can get a fast acting type fuse as well if you want.

I ran the wire inside the harness, got to modify it for electric choke, msd ign, etc while in there.  Also get to check for any melting etc.

Tom