I traced a couple more fuses. It's not pretty, but this is just what I have so far. I'm not going to bother making it pretty until it's been checked by other people.

This is for 77 and 78 (with differences between the years noted if there are any):

Hopefully someone who is bored will check my work?

 

58 minutes ago, Captain Obvious said:

I traced a couple more fuses. It's not pretty, but this is just what I have so far. I'm not going to bother making it pretty until it's been checked by other people.

This is for 77 and 78 (with differences between the years noted if there are any):

Hopefully someone who is bored will check my work?

 

This will be invaluable for the community.  Weird that the voltage regulator would have a fuse. 

That connection to the 77 voltage regulator is the "IG" terminal and I don't remember the details of that what that connection does.

I converted my 77 over to the 78 style internally regulated system a couple years ago, and as part of that conversion, I purged my brain of the finer details of exactly how the external voltage regulator works. I used to know, but now that I don't need to know anymore... Most of it left. 

So, having a 78, you don't really need to know either.

I traced a couple more fuses. Note that this has not been checked by anyone else, but here's the latest. Also note this is for 77 and 78. I haven't looked into any years earlier than that:

Edited July 7, 20213 yr by Captain Obvious

This is awesome!  Did all cars come with glovebox and cigarette lighter lamps?  I don't believe mine has either.

Not pretty, but I'm hoping it's accurate. I'll give it some time to cure and then I might spend a little time making it look prettier. And if I get a chance, maybe I'll look at some 76 or earlier.

I don't know much about the 240's, but I believe everything 260 and 280 had both lighter and glove box lamps. Maybe your bulbs are just burned out?

Forgot to ask. There are some things on that diagram that might not really make sense to some people...

Do you know what means when there is a fuse for "defogger switch" and a completely separate different fuse for "defogger relay"? Does that make sense?

 

 

(Just in case it didn't make sense) The "defogger switch" is the low current side. It energizes a relay (the "defogger relay"). The current going through that fuse does actually ever get to the defogger itself. The fuse feeding the defogger relay is the high current side and provides the current that actually flows through the defogger.

But the tricky part is... If EITHER of those fuses is burned out, the defogger won't work.

Does any of that make sense at all? LOL.

I also don't like "steering lock switch", but that came right from the documentation. That is the "will activate the beeper if the key is in the slot while the driver's door is open". But I ran out of room.  Haha!

1 minute ago, Captain Obvious said:

Forgot to ask. There are some things on that diagram that might not really make sense to some people...

Do you know what means when there is a fuse for "defogger switch" and a completely separate different fuse for "defogger relay"? Does that make sense?

 

 

(Just in case it didn't make sense) The "defogger switch" is the low current side. It energizes a relay (the "defogger relay"). The current going through that fuse does actually ever get to the defogger itself. The fuse feeding the defogger relay is the high current side and provides the current that actually flows through the defogger.

But the tricky part is... If EITHER of those fuses is burned out, the defogger won't work.

Does any of that make sense at all? LOL.

I also don't like "steering lock switch", but that came right from the documentation. That is the "will activate the beeper if the key is in the slot while the driver's door is open". But I ran out of room.  Haha!

I was curious about that.  It's surprising to see how much current the defogger actually pulls from the system.

I took a couple minutes and looked at the 76 wiring diagram. The fuse list I posted above will not work easily for 76. They really screwed with some things in 76. Enough that it makes me wonder if it's a documentation issue, or if the 76 car really matches the FSM.

Anyone with a 76 want to do some poking around to help the cause?

Which wiring diagram are you using?

The 1976 Service Bulletin describes some changes from 1975.  Might be worth a browse.  And the eye-straining black and white diagram downloads with the 1976 FSM.  It's actually a very crisp copy, compared to some, still just all thin black lines.  I got mine from a different site though, not 100% on the CZCC version.

https://www.classiczcars.com/files/category/5-service-documents/

The problem I'm having is in the documentation from the 76 FSM. Kinda goes like this:

Here's a snippet from the 76 FSM showing the fuse block layout. Note that it shows the turn signals (FLASHER) coming from the third fuse down. This makes great sense to me since every other year from 74 through 78 uses the third fuse down on the left column to power the turn signals:

And here's a 76 cover I have here that confirms the accuracy of the pic in the manual:

But then here's another snipped from the same FSM that details the turn signal circuit, and it uses a different fuse. According to this detail, the turn signals come from the FOURTH fuse down:

And important to note that the wiring diagram agrees... According to the wiring diagram from the same FSM, the turn signals come from the FOURTH fuse down.

So which is correct..... The parts of the manual that say third fuse, or the parts of the manual that say fourth fuse?

I sold my 76 otherwise I'd have an answer right now.  Should be able to pull the third and /or/then fourth fuses and see what happens.  I'm going to go with the BE-12 diagram is wrong.  The fuse box cover has a lot more expense invested in it.

Does 77 have the same issue?  I've never been sure if there is a "real" 77 FSM available on the internet.  The ones I have downloaded look like 76 FSM's.

Actually, I just opened one of my 77 FSM's and it shows publication in 1976.  Which makes sense for 77.  And it shows turn signals on fuse 3.  So, it looks like the "76" FSM might be wrong.

Page BE-10 from the 77 FSM.  That's one of the beauties of the old Z cars.  So many layers to peel.  It's not just a sports car.