Tackling a full rewire on a 67 and a few other things too

[Marshall]

Day 3: Great progress today. We now reliability have horn, brake, running, signal, headlights working... and a functional fuse block! (a HUGE thanks to Cam!

We cleaned a bunch of connection and cleaned up in the dash. In looking around the wiring we found this:


In the long term maybe a full rewire is justified, but for now we've decided this harness is repairable and actually in pretty good shape. (the above picture is the worst of it) And keeping it as close to original is always my first choice

[zed]

Heat shrink tubing will seal the punctures from further exposure to the elements.

[moore_rb]

The question we have now about the alternator is how we can tell which connection should be for the charging light and which should be the load sensing lead? We haven't found any markings anywhere and given the ridiculousness of the other wiring we're hesitant to assume that it was correct.

Go back to your original picture you posted of the alternator wiring. I think the 3 terminals on the alternator were correct

The short green wire that went to the BAT terminal on the back of the alt is your load sensing terminal for the internal regulator. The other one is the dash light lead.

The dash light lead should go to a 12v light, and then from the light to a switched 12v wire (the coil wire is not the ideal place, but it would have worked. Better would be the IGN terminal on the key switch)

so, it sounds like yours didn't have a light in the circuit at all...? Yeah. that's bad- The alternator was probably operating in "max load" mode 100% of the time. (hence the 15-16 volt readings)-

The dash light circuit is actually a comparator that evaluates the voltage on the alternator light, versus the voltage from the load sensing circuit, and it applies whatever voltage is necessary to equalize the voltage potential across the light. When there is 12v on the IGN side of the light, the comparator tries to put 12v on the Alternator side of the light, which makes the light go out). When the alternator isn't turning (or when it goes bad) this comparator acts as a ground shunt, causing the light to come on and stay on.

[moore_rb]

In the long term maybe a full rewire is justified, but for now we've decided this harness is repairable and actually in pretty good shape. (the above picture is the worst of it) And keeping it as close to original is always my first choice

That's good. Your wires may be old and crusty, but they really don't have to move very much current; except to power that aftermarket AC, which should be totally de-wired, and then re-wired correctly after all the Patrol's native circuits are working correctly again.

Let me know when it's time to re-wire that A/C, and we'll draw you up a clean circuit for it (using a relay for the compressor clutch)- I'll probably make Faux40 do that- he's better at drawing diagrams than me...

If it were up to me, you'd get a used coffee-shop napkin in the mail, with the circuit drawn on it in red grease pencil.

[Cameron110]

Rob thanks very much for the further explanation of the GM three wire, that's super helpful. being more of an old motorcyle guy means i know generator and magneto systems better, this set up is new to me.

our full update for the day will come later but we have a stupid question that we are stalled on at the moment. the filaments in the left front blinker are reversed (so was one on the back), i've pulled the two nuts from inside the fender on the front and pulled\pried as hard as I dare but the light housing won't budge. Am I doing the right thing to get them off and apart or should they rotate and pop open like the rear lights ?

Thanks

[moore_rb]

The front marker light trim rings and lenses should twist and pop off just like the rears (Be careful with those glass lenses! They are rare as hen's teeth)

the screws in the back should release the base of the light - what's left of the original rubber gasket may be stuck

[ckhorne]

I rewired my '67 patrol a year or two ago, and extremely happy that I did. I did a bit of a writeup on it here: http://60patrol.com/forum/viewtopic.php?p=22718#p22718

I tried tracing all the original wiring to begin with, taking notes, etc, but in the end, found it much easier to just pull out all the existing wiring and using the wiring diagrams to run everything new. The wiring in the patrol is fairly simple, and with a decent wiring kit, you won't have too much trouble wiring things up as needed.

I agree with others here - your two gauges that aren't working are probably a result of a burned out regulator, although IIRC, the oil pressure gauge runs off of 12v, so shouldn't need the regulator. Check the wiring diagram.