Killer Instincts

Hey y'all,

Long story short, I have a '68 small block vert that I bought sight unseen, and it was significantly more of a project than advertised. Basically a car I bought as a driver needed all new brakes, steering column rebuild, ignition/distributor rebuild, carb rebuild, etc to even make it drivable. Okay, rant off, and an expensive (to me) lesson learned.

The main problem: despite a new alternator (NAPA P/N 213-4011, built-in regulator) and battery, I can't get the battery to charge up at all. Voltage at the alternator reads pretty high, 15.5V or so on the multimeter, but the battery is reading < 12V throughout the RPM range. I tried disconnecting the battery with it running at 1500-2k RPM and it immediately died, which I think suggests that the alternator effectively isn't hooked up to anything. I was able to drive it ~20 miles or so today before it started stumbling over itself on tip-in (not a carb issue).

The wiring is kind of a disaster, another pleasant item that was misrepresented. It appears to still be routed through the original voltage regulator (which I'm sure is shot). So, I have a few questions - first, to see if the regulator is the issue: which two wires should I pull from the 4-wire connector to the regulator in order to connect them and effectively bypass it? Second, if I decide to go further, would replacing the whole mess with the Lectric Limited engine wiring harness (link) be advisable? Finally, (broad question) what are other hotspots I should check?

I'm really hesitant to put any more money into this car, and I don't exactly have an excess of time. At this point I basically just want to get the damn thing reliably drivable and sell it.

A88FXRS

ohm out the alt charge leg to battery to see if you have continuity to batt.

ronarndt

I tried to work with the really bad wiring on my 68 convert for about 6 months when I bought the car three years ago. I finally bit the bullet and spent the $$$ for a new wiring harness. It was expensive, but it cured all of the problems I was having. Not sure you want to spend money on the car if you plan to sell it, but if it cures your electrical woes, you may want to keep it.

terrys6t8roadster

An alternator with a built in regulator needs to have the original regulator bypassed. Remove and dispose of 68 regulator. Use original wiring to feed new internal reg alt. Reuse the red wire [it is battery + pos] and the brown wire [it is ign hot]. These two go into the plug of the internal regulated alternator. Tape off the other two wires. Make sure you install a ground wire from alt to engine block.T

Killer Instincts

Thanks guys. The engine wiring harness is only $200 from Eckler's, I'm thinking that might be the best choice. It's hard to tell with the wiring as it is currently, what exactly is happening - there are two wires that plug into the alternator in addition to the positive and negative terminals, so a previous owner *may* have already bypassed the external regulator. I will have to cut it apart and find out.

Other than that, I'm thinking the full rewire the car needs (and deserves) will be a project for the next owner. I love the '68 but I really find myself missing the modern amenities and performance of the modded C6 coupe I sold last year after daily driving it for the previous 6.

caskiguy

I sold a 2001 C5 with really low miles and although I've acquired a 70' that I've completely stripped down to rebuild there are moments when I ask myself "Why did I do this exactly" ?
Life goes on.

wadenelson

Get thee to an auto electrician.

Killer Instincts

Definitely advisable, but expensive.

carriljc

Break it down into sections. With the engine running and after verifying that the generator output is about 14 VDC, then take the following readings. Be careful with that starter post reading...it's going to be near the exhaust down there and the engine will be running.
1. Take a voltage reading at the alternator output. Write it down.
2. Take a voltage reading at the Horn Relay terminal. Write it down.
3. Take a voltage reading at the Starter Post. Write it down.
4. Take a voltage reading at the +Battery Terminal Write it down.

If you report back those reading then it should be possible to ascertain where there might be an OPEN. I rewired mine to go to an internally regulated alternator and eventually to a CS-144, but we can discuss that later if you want to go that way.

Killer Instincts

Thank you, that's a solid plan of attack. I'll get to it when I get some free time... either that or I'll just bite the bullet and take it to my wiring guy.

Richard454

If you replace the harness- it'll still be set up for externally regulated alternator.

This will solve your issue-

https://www.speedwaymotors.com/Alter...ss,116911.html

Peterbuilt

So the Corvette is new to you and came to you with the problem of the battery not getting charged.
Can you compare the '68 and '69 schematics and determine what is connected to what?

https://docs.google.com/viewer?a=v&p...jI1NDMyY2I3YzQ
https://docs.google.com/viewer?a=v&p...GZjYjVhZWU4MGQ

Killer Instincts

That's useful information, thank you.

Edit: ordered new wiring harness and the conversion kit. I'll probably just have my wiring guy install them, as it will take him way less time. And then... probably up for sale. Maybe.