You'd be amazed at how much dirt I've managed to clean out of this harness, cant believe it could of gotten this much in it! So as I un-molest this wiring loom I keep running across little changes that are a bit confusing, I've completely unwrapped it which is a good thing cuz chasing these issues in the car would be a royal pain.

here's part of the loom, this has 2 fuse holders - previous owner must of had another power need, it was attached to the blue switched lead running down with the trans tunnel leads - it was also pulled out of the but connector in side the loom.. I think I'll replace the original white one with a new one as well







I assume this is a internally regulated alternator....







I also assume this is the correct jumper for the voltage regulator... white/black to white/red




I'm a little confused about this wire, looks like 12 GA. white/red trace located in the coil branch of the loom, I'm guessing this is the alternator feed but as you can see the alt wire is much smaller GA. - is this the charge wire for the battery?




Its a bit confusing but I think I'm almost there is getting it sorted out, if anyone can shed light on the 12GA W/R wire that'd be great.

Thx.
E

fat W/R is alt to battery

thin W/R is for charge light in dash

shoul be able to confirm that in the workshop manual wiring diagram

You will require an additional jumper for your socket where the old voltage reg was connected.

The OLD (externally regulated Alternator) had the "N" and "F" connected by the plastic "T" connector.

"N" Neutral was connected by a Y (yellow) wire.
[This is the top of the "T" connector]
"F" Field was connected by a W/B (White, black stripe) wire.
[This is the stem of the "T" connector]

New wring for IR type alternator

Splice the W (white) wire to the Y one. (Sense circuit)
Splice the W/R (white/red) wire to the W/B one. (Lamp circuit)

If you can sacrifice the un-used socket from the voltage reg , its looks way neater.

Also from my expirience [can be very time consuming] is to avoid using crimp connectors and splades. Solder and heat shrink is the way to go. Crimp connectors work but can be prone to intermittent failures over time [very annoying to troubleshoot] and also a small voltage drop can be sometimes be induced due to to poor connectivity.


Also with the last pic, That gauge wire and position is consistant with the wire that connects to the battery via the fusable link. I'm not a great fan of fusable links and replaced that component with an auto reset circuit breaker. ~ 50A from memory. [taking into account that Alternators can spike in there delivery of Amps. For my track car I am only running a 40 Amp unit as I dont have much electrical current draw other than ign and pumps. Rally cars would use larger units to power driving lights etc...
cheers
benny

thanks for the in depth info, appreciate it! I'll pay attention to it while I'm finishing getting the loom ready - may have more questions though.

Its a good tip on the solder connections instead of butt or spade, I should of thought about it & probable will use it for the internal loom connections as I don't want to chase them again.

I did find a source when I was re-doing my H1 Kawa for OEM style connections, haven't bought anything yet but they look pretty good.

Looks like nice stuff with the original style soft casings
http://www.vintageconnections.com/index.htm

I still use butt and spade type connectors, I just solder them to the wire rather than crimp them. An for groups of connections I usually go for a plug/ socket type connectors for multipin stuff.

Hey Benny, that W/R is definitely the fusible link wire, I confirmed it on my other loom. I like the idea of a circuit breaker & was looking for the amp rating of the original fusible link but didn't find it in a quick search - I know you said some where between 40 & 50 Amp - I found this...

http://www.mcmaster.com/#dc-circuit-breakers/=c9vec4

Is this similar to what your using & do you see any problems with something like this? I was thinking of a compromise of 45 Amps.....

thx.
E

BTW - took your advise & soldered the wires both together & to the connectors, also sacrificed a voltage reg. plug to make the jumper - worked well.

EDIT - so after a little more searching I found some info from DD:

Quote:

Is the relationship between a 30A fusible link wire & a 30A DC breaker going to function the same way? Are they equal is performance, the same thread stated that an actual "fuse" & fusible wire performed differently.

This the style that is suitable for automotive applications




They are commonly available at most auto stores... ranging from 12v 10A to 50A in increments of 5A from memory

Evan, the fusbile link is sized for the existing wires. You should not simply fit a larger fusible link unless you change all the wiring. In other words, the 20 gauge Fusibile Link protects a 16 guage wiring system. If you fit a larger fusible link and then get a short, the link won't blow before the harness. Not good.

Note that the original Datsun 1200 fusible link is green, and is attached to the Battery cable, not part of the wiring harness.




Both green wires are the same. Top: New, Bottom: old and faded

If you want to switch to Circuit Breaker that is fine. Do it as close to the battery as feasible and make it an 85A unit, as the stock wiring harness and fuse box is 85A total. If you want to add more capacity then add a 2nd circuit break to protect your new additional wiring. The stock wiring presumably will not handle more than 85A.

Yes, I used this exact type to protect my new wires for power windows & power seat in my 1200. The wiring for this was totally separate from the existing wire, existing fusible link and existing fuse box.

Attach file:

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  fuse.jpg (17.94 KB)

Good to see your getting through it :) Were at the same stage. Lucky I've got an auto elec at work. 100% agree with re taping/ modifying loom out of the car.