wadenelson

Can anyone tell me how we fixed ANYTHING before we had Internet forums to refer to?

Sixteen years after this thread was originally posted and here I am... with questions, corrections, seeking advice...

Here's my story, bought a '68 after lusting after one for 50 years.... this despite my buddy saying "Get a '69, the '68 is a bastard child, they were still figuring EVERYTHING out, can't find two alike... innumerable dash configurations... blah blah blah.

Did I listen? Of course not. I was thinking of the canary yellow 1968 Corvette convertible I saw on the floor of Joe V. Clayton Chevrolet in Arab Alabama while my father was purchasing an even MORE expensive 3-row 1968 Kingswood Estate wagon.... did he listen to ten-year-old me? "Dad, buy the Vette instead! My brother can sit in my lap!" Of course not.

Stubbornness runs deep in our family...

I was butt-hurt about the wagon purchase until junior year in high school, when Mary-Lou Kortney demonstrated for me the make-out advantages of the wagon's waay-back.

Fast Forward to 2018... Scottsdale Arizona... out on a test drive in a Laguna blue 1968, sunny day, t-tops off... loud pipes... life doesn't get much better than this... unless you're 18, loaded to the brim with testosterone, and have a GF with one of those Southern hyphenated double first names who's willing... but back to the test drive, for now...

Tested the wipers and the headlights and the power windows....all .worked.... Figured that was $3000 right there I wouldn't have to spend repairing this car. ...but keep reading...



I think the second time I tried to use the wipers.... door came up but wipers didn't work. Sounded like the arms were jammed so I quickly turned them off.

After taking the grille off I could see the wipers had somehow parked below the little rest they're supposed to sit on and were jammed. Misadjusted park? Didn't even try to move now even after moving them to correct parking position? Why stationary now? Bent rods? Blown fuse? Blown motor?

Car has a variety of electrical issues --- parasitic drain, power windows suddenly quit working (worked on the test drive, of course) , intermittent no crank, as well as the wipers. Battery only charging up to 12.4, not 12.6+ Time to get to work...

BTW, I'm an EE, and taught Automotive Electronics @ a local community college. Been active on iATN at times. Wrote for Motor, MotorAge, MasterTech, etc...

Found the main ground from the battery (which had obviously been replaced at some point) bolted on top of undercoating. Shined it all up, dab of anti-seize, re-bolted. (Probable cause for under-charging)

Found all kinds of horrible 14AWG solid (non-stranded) white wire under the hood, splices everywhere, most of it doing absolutely nothing. Probably several pieces broken inside the insulation from engine vibration. One set of white wires powering an (inoperative, of course) electric radiator fan through a too-small diode stuck into a fuse connector, buried in electrical tape, baked (char-broiled?) to carbonized perfection... tied directly to the alternator (Without the diode the electric fan would backfeed the ignition and prevent the engine from shutting down, according to the service notes)

I got the radiator repaired, repaired the rest of the cooling system and with no further need for an aftermarket electric fan removed the rest of the nonsense solid white wiring under the hood.

(What kind of moron uses solid wire in an automotive application. Making a list of the folks I'm going to strangle some day)

Parasitic drain seemed intermittent,. Car just wouldn't crank sometimes and battery wouldn't have a full charge.

Finally decided the intermittent no-crank MIGHT have something to do with the aftermarket alarm half-assedly installed underneath the dash. That or just a worn out ignition switch. (Starter tested good when hotwired during a no-crank).

Learned the joys of cluster removal in a C3. WITH air conditioning, I might note, as that asphalt-goo-covered left ductwork makes everything else 10X as hard, like plugging those little light bulbs back in...

Ripped the alarm system out, repaired where it had spliced into the big purple wire in the bundle... Removing an aftermarket alarm out always reminds me of the movie Alien, or a surgeon, opening up a gut and seeing cancer everywhere.... left a few scotchlocks in place figuring better off just not to touch them...

I clean stuff up, zip-tie bundles, clean up some original FACTORY grounds bolted on top of paint on the left side of the dash... remove more do-nothing wires...

The ammeter wasn't working when I bought her...and I've got two twisted yellow wires still unidentified (UFO wiring) coming from that area... might touch 'em with a 9V battery just to see if it makes the needle jump) Those two (by way of 4 splices apiece) connected to more do-nothing wires in the engine bay, one of which went to the alternator connector.. perhaps some home-remedy for a non-working ammeter??? No idea how the ammeter is s'posed to be wired in this vehicle... schematic anyone?

The pile of solid white wiring I've removed, home-made "diode packs", alarm wiring,... continues growing.. Note the two pieces with three splices apiece within six inches...



So now I"
'm going after the inop windshield wipers and I find my parasitic drain -- the electrically operated vacuum relay under the dash is warm to the touch. On all the time even when the car is off. Hmm, shouldn't the wipers be powered through an ignition [controlled] feed?

Time to find a schematic.... or at least a theory of operation. Google search. Land here.

I find this gem: 1968 version - The circuit for 68 is unique and so far I have not found it in any service manual ....

Followed by a description of the circuit itself. Huzzah!!!!

Being an EE, I decide the proper way to proceed (most efficient?) is to draw out what OP describes .... "the power to run the
motor comes through the wiper door actuated limit switch..."

Figure I'll draw it out, go compare that to what's on the car, make any quick fixes necessary, and be on my way to the inaugural Durango Colorado Corvette Club meeting Wednesday night. Even if it's raining.

Rough schematic, based on description:

https://i.imgur.com/nluLsYO.jpg?1

https://i.imgur.com/nluLsYO.jpg?1

Oh, if only things were ever that simple.

OP's detailed description of the circuit, well, the inconsistencies become apparent when you try and draw it out

In one place he states "Red is power"

In another he states: "the power to run the motor comes through the wiper door actuated limit switch"

And in another he states: "and a light blue which changes to a black going to one side of the limit switch

I've posted my hand-drawn schematic twice but it won't seem to attach to this post? Image limit???

The next tab on my Chrome screen is "Wreck on the Highway." (Youtube featuring Bruce Springsteen)

This here, this is "Wreck on the Schematic" Either the power comes in via a red wire, or a light blue wire, but probably not both" I can't draw it both ways. (I tried!)



BTW, drop the steering column (2 bolts) and it's a whole lot easier to remove/install that cluster.... now you know...

Find yet another gem in this thread: Many a frustrated owner has had the experience of
(apparently) failed wipers because someone turned the rotary switch to see what it operated.

Did I do that? Well, playing with ***** and switches, that IS something I tend to do...

So my game plan now is to head out to the garage (the rain has let up a little) try and draw a schematic of what's actually there...

Maybe take a few test measurements, see what actually is and isn't hot...

Sit down with a tasty beverage and compare the two drawings.... see what jumps out at me...

Look for the "fusible link" off the horn relay that supposedly powers the wiper on a '68. (take time out to hunt down and strangle some GM wiring guy?) . Where is the horn relay, btw. Anyone know?

Try turning the rotary **** and see if that's actually why my wipers ain't working...doubt it

Figure out how or why the wiper vacuum solenoid is always hot, ignition off, and either fix it or wire in a relay so it's not

Eat lunch...

Check back on this forum to see if anyone has posted a BETTER 1968 wiper schematic, or has any tips....

UPDATE: Here's a link tp the million-dollar 1968 diagram --- Thanks Willcox!!!

https://www.corvetteforum.com/forums...or-wiring.html

Cheers! Wade Nelson Durango Colorado

Peterbuilt

Hi and Welcome,
You can find some basic information about you '68 Here:
https://www.gmheritagecenter.com/gm-...tion-kits.html

There are many posts on repairing the '68 wiper motor and door but you will have to search for them.
Willcox Corvette has a how-to.

Here's a 1968 internet schematic, I can't vouch for its accuracy but it might help.
A better schematic is in the '68 Service Manual.

https://docs.google.com/viewer?a=v&p...jI1NDMyY2I3YzQ