https://www.facebook.com/pickflipdrive/videos/295412271101042/And I did not pay anywhere near that, it was close to what they bought the thing for... The guy before me bought it from the show...and he did not pay what they wanted either..

The car runs down the road really nice, smooth at highway speeds, no bad suspension noises. just a bunch of little things that are growing...

This charging issue it pissing me off, I gave up drinking for lent and guess what... Lent is Over!!!

60

 

27 Volts? Great Scott!

There's a wiring diagram here:
http://wordpress.keystonestatecorvet...m/?page_id=118

I'd look for continuity from your alternator to the positive battery terminal. There are fusable links in between that may have fried. Look near the starter, the starter solenoid extension harness is a likely culprit. Also, make sure the alternator is grounded properly.

The charging circuit is most likely completed through the starter/starter solenoid, not all the way back to the battery.

If you don't have a deep discharge battery, you should keep it charged up, or the battery will be damaged and not have enough "oomph" to start the engine. If you DO have a deep discharge battery, using the alternator to charge can put too much current through the stock wiring if you have a higher current alternator.

 

bikespace,
You and some others are on to something, the alternator is putting out that 27 volts but it's not getting to the battery, it reads 12volts while the alt is @ 27 so something is open. I've had enough for one day, thanks for the diagrams, I need to order a book too...

60'

 

OK, so I took a break and did yard work for a day...and bought some wire because there is some ugly looking wires in this car. The MSD ignition hot wire was on the alternator so I moved it to the wiper hotwire so it wasnt getting the 27 volts. Started the engine, still 27-actually 28.5. There is an orange wire hooked up to the junction block in the battery compartment with a 20 amp fuse in it, I pulled the fuse and everything still worked, lights fan seat etc... So I started the engine, volts are now 35. Replaced the fuse, volts stay at 35 with engine running, everything works, this is impossible... I'll take some pics in awhile//...
CAn an alternator put out that much? (I am sure of my meter)
Can I disconnect my present alternator wire and just run a new one too the battery as a test...??

Frustrated 60

 

If you have long enough jumper cables, try using them to jumper between the alternator and battery.

 

Please do some continuity tests first, engine off, and post some photos!

Where are you measuring this 35 V? Is it from the alternator output terminal to ground? Which ground? Do you have nearly zero ohms between the engine and the negative battery terminal?

 

This is the hot wire from the alternator to the junction block in the battery box, it is disconnected at both ends and has continuity... I also have good grounds from engine, alternator, any metal under the hood tested direct to the negative battery terminal.


See that 20A fuse, do all of these cars have that? It's for that orange wire that looks like it goes to the computer, but this has a crate engine with MSD ignition so I don't think the computer is even being used..?? Car runs without the fuse...?? And Everything else look like its working... I have disconnected the big stereo fuse for now...


opps, upside down, this is the alt hot wire, everything connected, engine off, 12.4vdc, I also have that on term #2 or the small plug and a couple volts on the brown light wire.


I don't know why these are upside down they are OK on my PC,,, This is with the engine running, it was 27, then 35, now 38 and I have not really done anything, the dash guage shows batt voltage, no charge and the hot wire in the battery compartment also just shows battery voltage, - I have no idea how that can be since I have continuity through the wire unless its got some sort of splice in it somewhere. Everything that worked before still seems to work, I just don't see how this is possible... Help, before I lose my mind...

60

 

Lionel,

I was going to use my jumper cable for that but when the voltage went to 38 i backed off..got skeered... What happens to my car/dash/other wiring if I run that kind f voltage through it....?

I think I'm gonna drop my old alternator in without doing anything else and see if the voltage changes... I don't want to fry this car's electrical system... 38 volts is alot...
Thoughts?

Thanks 60

 

Another thought, what would happen if I ran the alternator with the hotwire disconected just to see what the voltage is? Would that fry the alternator?

Thanks

 

Put the original alternator in and initially got just battery voltage when running and figured it was bad, noticed the Alt light on so I reved the engine it went out and the voltage jumped to 36-38 at the alternator... but not in the battery box...
So I have two alternators basically doing the same thing.... neither is good...

60

 

It's hard to tell in the photos. Is there a black ground wire attached near where you are connecting the negative lead of the multimeter? There should be, and it should connect to "ground", either the chassis or the engine (and the engine should be grounded to the chassis separately).

With no load, the alternator output is floating. But before you try to connect the Alt+ to the Batt+, make sure the alternator is grounded properly.

Can you measure the resistance between the alternator (case) and a few points, including the battery ground? All should be zero, or very near zero (a fraction of an ohm at most). Also between the engine and Batt -.

 

The alternator to battery wire is bad. It must be or you wouldn't get a different voltage at each end. Measuring the wire with an ohmmeter on the 200 ohms scale won't detect a weak connection that can't handle the current when the alternator is working. You'd need a micro-ohmmeter that puts a significant current down the wire for that. We have portable ones at work, they put 10A through the wire and measure the voltage drop to figure out the resistance.

 

The ground wire on the alternator is used to ground the radiator support to give a ground for the lights and horn up front. It's not there to ground the alternator, but rather used as a grounding point for the electrical stuff on the front of the car.

 

Fair enough, but it's still worth checking that both the alternator and engine are grounded properly. It's a NOM, so who knows if the mount is grounding to the engine the way the stock mount would.

Clearly the alternator output is open.

 

bike space,

When I checked my grounds to the battery I did multiple spots, the Alt, Engine manifold, steering shaft and a number of other spots. That clip connect you see was just an easy spot for my meter.

I want to thank you both, and you both are telling me the alt wire is open in some way..My problem is it seems the only way to test it is to use another wire and see what happens... I can see where that would probably work but I'm a cautious sole. Before I do that, maybe I could incorporate some sort of fuse on the new wire in case the voltage/current was too much. What sort of amp fuse would you recomend. I have some 4 gauge stranded wire but I'd like to at least fuse it just in case...that 38volts still has me worried...
Sorry to be such a chicken I just can't understand how this could happen, I think there is some bubba wiring under this car that I have not found or understand

Thanks again..60

 

If you have a fuse, it couldn't hurt. 20 Amps perhaps? If the battery is fully charged, it should be okay. You might need a bigger fuse if the battery is discharged some, so to be as safe as possible, charge up the battery first.

The alternator output is floating because it is disconnected. It will tie to the battery voltage if connected correctly, so the rest of the car won't see more than 14V or so, and the alternator output will be fixed at the battery voltage, with a current corresponding to the state of charge of the battery (fully charged battery = very little current from the alt).

 

Talked with a friend today, he has 6 c2 & early 3's.. he said to disconnect the alt hot wire and wire in my drop light with 100 watt incandecent bulb from the alt output to ground... He agrees my wire is open or partially bad and this should provide enough resistance to get the alternator regulated... What do you think? I've got it wired up just making dinner first...lol -(chicken!!!)

Thanks, 60

 

That took it down to 24vdc, the small plug stayed at 12...
I'm just having a hard time connecting something thats putting out that kind of voltage to a car with 40 year old wiring and components...

60

 

The only way to get the alternator to do any kind of regulation is by connecting the alternator output to terminal 2 in the connector.

The regulator will continue to go fully on causing the output to also go to the full-on voltage as long as terminal 2 is connected to battery voltage and the output stud is left open circuit no matter what else you try.

 

Exactly. The alternator needs the feedback loop completed.

Also, the battery will clamp the voltage to 12.5V, or whatever it happens to be. It can sink a LOT of current. The rest of the electronics will not see high voltages, as long as your grounds are good, and the connection to the battery is good.