HELP!!! 68 Buick Skylark Sudden electrical failure yet car starts

I was getting a 68 skylark ready for tomorrows cruise, yesterday did a safety check of everything wipers light blinkers heater everything worked.
Today hooking up the final ac duct work under the dash and after buttoned it up started it up, fine turned on ac compressor kicked in , turned fan on , nothing, turned wipers on nothing , headlights nada??? fuses look good.
when I turned key on on, gen and oil warning lites lit up. Then I heard a groaning from voltage regulator, which is fairly new, it sounded like a flasher, I checked the emergency flasher on column and it was on.
Where do I check next? could I have knocked something loose I am in shock! no pun intended! No power to any of the fuses that I can measure . Since this was the duct that ran under the column could I have pulled something out? the duct snaked under the wiring harness from the steering column could that be the issue? 68 ignition switch is on the dash BTW
Any fuse links in that area?

Thanks

 

As a side note check voltage at battery 13.6 static 17.9 Running

If it is voltage regulator problem could that have burnt out a link?

 

Horn relay should be up in that area .. voltage is def. too high

 

Car starts right up , only other things that works are the gen , oil & hot warning Lights on dash when you turn the key. nothing else whatsoever

Ive been pouring over diagrams , where are the links?

 

Horn relay could be the problem?
Thanks for the tips

 

I thought the 68 horn relay is behind the drivers side headlights? Mine is.
You may have knocked a ground wire loose under the dash while installing your ducting, I would check that first since
everything worked before that.

Tony

 

Fusible links are down by the starter in the wiring harness. Big #10 or #8 red wires go to them. It will be obvious if they are fried. You need a new voltage regulator- that one probably has a stuck contact. It is charging way over normal, which is around 13.5V to 14.5V. On my '68, the horn relay was on the radiator core support, and voltage regulator was on the firewall.

 

I may not be clear.

The only thing that works is the starting system and the warning light. No power to the fuse box or any other accessory at all

 

Horn relay? no horns, one wire coming out to ground one to wire harness , 2 to nowhere (missing horns I assume

 

*UPDATE*

Swapped out regulator with a parts store brand , only one available today. Now no start at all, Have about 4 volts to fuse block with key to acc, could this be ignition switch?

Also looks like another horn style relay by fuse box

 

You have a weak connection somewhere, to have that low a voltage. You're going to have to do some wiggle testing with a meter or test light to indicate where the weakness/poor connection. The "relay" by the fuse box is likely the old ignition key buzzer.

 

I have a 67 and a 69 schematic but no 68, which one do you suggest. You are correct I am confused ou:

Thanks for the suggestions

 

I had taken photo of my schematic for a previous posting ; this photo might be cropped but hopefully help you out . Good luck !

 

'68 and '69 wiring diagrams are essentially identical; I have had my hands into both. The big difference is with the ignition switch on the column in '69. But the wires are all the same size and color.

 

Ok Fresh start

First I Checked battery and charged it to 100%

Cleaned Cable ends, installed a new negative cable since it looked as old as the car

went to fuse box made sure it was tight

connected power, turn to on Oil & gen light came on as before
Turn to start Temp light joined the 3 as it should but nothing.

Regulator wires with car ignition turned to on since it wont start

4 Brown 12.65
3 red 12.68
2 white thought I saw a some MV but could not get it to repeat
1 Dark Blue 0

As I have been at this 3 days now and in the shop since 630 this morning decided to take a coffee break

I went back to verify the ground strap behind the right head & it crumbled in my hands.

I hooked a jumper cable to the exhaust manifold and frame and went to start

Still no start but lights & wipers came on!.


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since the strap is bolted to the head and is next to impossible to reach with the AC unit there is there any other suggestions on where to mount?

 

Also just swapped the Duralast voltage regulator for the Napa Echlin (both brand new) and started it right up! and everything works