Cuda overcharging? Please help...

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ToastToAlmost

ToastToAlmost

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My voltage gauge in my cuda is telling me it's getting about 14volts at idle, but whenever I give it gas it makes it's way up to about 18volts. It's a brand new alternator and I've gone through 4 voltage regulators trying to get this thing to charge right. Any idea what could be causing this? If anyone could throw some ideas my way as to what the problem could be it would be great. Thanks guys
 
Check the wiring between your alternator and your voltage regulator. Mine did the same thing and I found a wire that was grounding out on the firewall behind my coil.

Mine was intermittant, but once I found it and covered up the bare copper wire, it stopped. I've also upgraded to the two field alternator and had run my own wires to the voltage regulator so the stock wiring didn't get over heated with the higher output of the new alternator, but the premise is sound. There is a wire that is shorting out that is causing your charging system to over charge.
 
You didn't mention what alternator or regulator you have but your alternator is working great, it's just not being regulated. You either have a bad regulator or it's not wired correctly or you're field winding on the alternator is getting full voltage from another source (such as a short). Pull apart your harness from the alternator back to the regulator and I'd bet you'll find the problem.
 
This will happen if the regulator loses its ground. Please do describe your charging system configuration - is it stock '65, or is it stock '70-up, or is it a mix of the two systems? Where are you getting the alternators and regulators?
 
Could also be that the regulator is "seeing" less voltage than the alt is putting out. If there is too much resistance in the wires headed to the voltage regulator, the regulator will see 12v when the alt is putting out 14v.

Dan, Correct me if I'm wrong, but if the regulator looses its ground or it's connection is marginal, the same thing happens. The ground is lost so there is nothing for the regulator to reference the input voltage signal to. Thus it does not regulate the alt, it lets it go wide open.
 
the voltage regulator does need a chassis ground at its mounting hardware. That ground path can be lost again if the ground strap between engine block and firewall is missing.
 
player1up said:
Could also be that the regulator is "seeing" less voltage than the alt is putting out. If there is too much resistance in the wires headed to the voltage regulator, the regulator will see 12v when the alt is putting out 14v.
Click to expand...

Quite right.

Dan, Correct me if I'm wrong, but if the regulator looses its ground or it's connection is marginal, the same thing happens. The ground is lost so there is nothing for the regulator to reference the input voltage signal to. Thus it does not regulate the alt, it lets it go wide open.
Click to expand...

Also quite right.
 
I can't seem to find a bad ground anywhere. Could it be anything else? I know next to nothing when it comes to electrical. The car has a 440 out of a 77 RV in it, and is running the electric ignition setup from it. Not sure that's relevant or not, but the first two regulators I got were only charging 12 volts at idle as well as with throttle, it wasn't until I got more expensive ones that it started charging okay at idle and overcharging with throttle... I just figured the cheaper regulators were both flukes
 
I also just want to add that it's a 2field, 60amp alternator... I'm wondering if maybe my problem might have something to do with the ammeter?
 
It might be something as simple as a weak battery. Let it go for a couple of days and see if it settles back down. The system might just be doing it's job and recharging a low battery.

George
 
If you've checked all of the grounds, move to the power side of the equation. My earlier post was trying to explain that there are 2 things that could cause the same symptom.
Pick up a cheap multimeter and with the engine idling check the voltage at the line that runs to the regulator, then check voltage at the battery. I'm not sure if it's the blue or the green wire (think its the blue one). A further test would be to put the negative lead of the meter to the chassis of the regulator then put the negative lead to the negative terminal of the battery while keeping the positive lead tapped to the input wire. If the voltage changes you have a ground issue. The input should be the same voltage as the battery is getting. My guess would be that the regulator input voltage is lower. It's not uncommon for a corroded system to lose 3+ volts. The reason for the voltage drop is that the regulator gets its power through the ign circuit, which runs from the battery through the bulk head connector, through the ign switch, back through the bulk head connector, and so on. ( please don't use my memory as a wiring diagram :lol: ) It's easy to see that if each connection only dropped .5 volts due to corrosion, the regulator is operating on bad info
My car had the same issue when I first got it on the road, ended up being a combination of marginal ground and low input voltage. Electrical issues can be time consuming but a methodical approach with a wiring diagram and a volt meter is usually better than swapping parts like I started off doing
 
I bypassed the ammeter today to see if it made any difference and also just because it's safer that way... Gonna go multimeter shopping tomorrow and see if I can pinpoint the source of the problem... I know a lot of those wires are looking pretty old. I would like to rip it all out and redo all the wiring someday but I need to overcome my fear of auto-electrical first haha

Hey player1up, I see you live in Orlando. Do you ever stop by the cruise nights at OldTown in Kissimmee?
 
Another thing I noticed is that when the turn signals are on the voltage gauge needle moves in sync with the blinker...

I took all 5lbs of electrical tape off the wiring and discovered that the wires from the the ignition, regulator, ballast, alternator, and the bulkhead were all bare and twisted together... Obviously the monkey job they did twisting the wires together isn't getting the best connection, but is that how it's supposed to be? I'm a complete n00b when it comes to electrical and have no wire diagram to use as a reference :( There's also a plug that I have no idea where it goes that comes from the ignition and the ballast... It's worth noting I have to start the car via push button...

I'm not too concerned about that right now though... I would just like to get it charging right so I can move it safely. What I don't understand is why (regardless of what's causing the overcharging) does it only do it when you give it gas? You'd think it would do it at idle too...

Here's the ignition with the mystery plug, and then a pic of all those wires twisted together... :(

9014b916f8b2ef611267822475.jpg


1294b916fce28a621267822542.jpg
 
I have been down to old town a few times but it's a trek from out east where I live. I should get down there more often...

I'm pretty sure that the red wires and the "twist and tape" method is NOT stock... :lol: Looks like you suffer from PO syndrome ( I'm sure the Previous Owner had good intentions... or maybe not... )
As for wiring diagrams, there is a ton of info here

The blinkers will bounce the ammeter, that's nothing to worry about, but since you bypassed it no need to worry about your car burning to the ground while you sleep either.

The pushbutton start thing could be that the ign switch or connections are gone/corroded or were forgotten from the cool wire nest.

Now the fun part. Forensic electrician work!! You have to try to understand what the PO was trying to fix and cross reference it with the original diagram before you just go tearing it out or who knows what you'll end up with.
 
Pulled that rat's nest of wires apart to today and rerouted it... No longer over charging, but now it's not quite charging enough. It's charging about 12V at idle like it does when the key is in the on position... I'm thinking either I still don't have it wired right or maybe it is the voltage regulator now?
 
Just posting an update to anyone who cares... Come to find out the previous owner mixed the power wire coming out of the bulkhead to the reg/ECU with the wire that goes from the bulkhead to the ballast. Seems to be holding a steady charge now at idle and throttle... Thanks for everything guys!
 
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