The Dodge Challenger Message Board

I am having a problem with my Challenger over-charging. While running it is charging at over 16 amps. The previous owner converted it to electronic ignition which I like. I have put 3 new voltage regulators, new distributor, new ECU and new coil but nothing has helped. If I unplug one of the field wires on the alternator it goes down to about 10. The car was running fine with a lot of power but I removed the engine to put in new cam and freshen up motor now it misses and getting to much juice. I am also only getting about 6 volts from the coil. If anyone can help I would really appreciate it.

OK. Something is up.

For a start. Batteries are charged at 14.5 VOLTS. Not Amps. I don't know where you are geting the amps from. They are not relevant. I will assume you just got the two mixed up and it was volts you meant.

Also the ignition system has nothing to do with the charging system.

If the alternator is wired correctly the regulator will stop the voltage output going over 14.5 volts. Without the regulator voltage output from the alternator will vary with rpm. i.e. the voltage will keep increasing with rpm.

If your output is holding steady at 16volts then the regulator is working but something is stopping it from seeing the correct output from the alternator.

So. My #1 guess is that the regulator is not earthed correctly. make sure its case has a good ground to the bodywork.

#2 guess would be a bad connection to the regulator.

Daves' advice as usual is golden, here is an electrical flow chart that really helps keep things in your head in order. Test the Battery first then the starter then alternator and wiring. But I think Dave's diagnosis is spot on and yes you must first understand the terminology and meaning of Amperage, Voltage, Resisitance. It's ALL tied in together and worth learning about. It will make your automotive experiences SO much easier if you learn.

I sanded the firewall where the voltage regulator bolts on and checked the wire running to the regulator and everything is fine. I bought a new alternator and an aftermarket amp gauge just to make sure it wouldn't my factory gauge. When I start the car both gauges peg out. I checked the blue field wire from the alternator and it was at 16 amps with the car idling. I do not know if this is right like I said I am lost when it comes to electrical problems. Thank you for helping me with this problem.
Jeff

Jeff, do you have a DVOM,(Digi volt/ohm meter)? It is a small electrical test equipment box. It sounds like either the voltage regulator is bad or the wiring from the regulator to the alternator is bad. This wire is called the 'sensing' wire and determines the output voltage of the alternator. It cause the voltage regulator to increase or decrease the magnetic field in the stator inside the alternator producing more or less voltage. The alternator has a set amperage it wont go any higher, but the voltage can exceed 250 volts. It can cause a fire easily. Thats why the regulator is so important. If you have replaced most of the electrical components, which it sounds like you have, I would re-check the wiring to the alternator/regulator circuit. At 2000 RPM's what is the battery voltage? Disconnect the BAT wire on the alt.(full field it), what is the voltage now? If there is NO difference in volatge the regulator or wiring is suspect.

I will do what you suggested. Thanks for your help. I will let you know what happens.
Jeff

Hold on!

If you really are measuring AMPS then what it is showing you is that you have a SHORT circuit somewhere.

Are you doing this with a fully charged Battery? Also 6V is not that uncommon to the coil after the ballast resistor. It may be going bad and causing your miss. It could be failing under load.

16A isn't too bad if the Battery is charging, after all the Alt will put out 45A or 60A whichever you got. What other things do you have on while the 16A is registering?

Do as previously mentioned with the Multimeter, this is important to check the voltages.

Tom

I checked the wire from the alternator to the voltage regulator with an ohm meter and it is good. I checked the voltage at the battery and it was 13 volts but when I put the motor to 2000 rpm's it was at 26 volts and I shut it off. I forgot to tell you earlier but when the previous owner changed it over to electronic instead of buying a conversion kit they used the engine wiring harness from a 73 or 74 Challenger. I was told this didn't matter but I would like to make sure. The ballast resistor is the only thing I haven't changed but I thought when it went bad the car wouldn't start. I don't know. [/b]

If the voltage is going up to 26 volts as you describe then the voltage regulator is not working. It is either a dead unit or not wired in correctly.

Forget about the IGNITION circuit and ballast resistor. These have absolutly nothing to do with the charging system.

The body of the car is grounded to the negative terminal of the battery OK isn't it?
There should be almost zero resistance between where you have bolted the regulator and the -ve of the battery so you need to make sure both the engine and chassis have ground straps connecting them to each other.

If you have a good connection between the negative of the battery and the case of the regulator it can only be a faulty regulator or wiring to the regulator.

I may not be checking to see if everything is grounded the correct way.
I have a volt meter which has a ohm setting. I touched one probe to the ground on the battery and the other to the radiator support where the groung strap is bolted to. My volt meter when checking ohm's will beep if the wire is good or in this case grounded. I also put one probe on the regulaor and the other on the firewall and it is OK. I also have a ground running from the engine block to the firewall which is checking OK. I checked both the blue and green wires from the alternator to the regulator and it is OK. If I am doing this wrong PLEASE let me know and how to do this right. Also I said earlier that the previous owner used a engine wiring harness from a 73 or 74 Challenger instead of the conversion kit. Do you think maybe this is causing my problem? I have bought 3 new regulators and it is no better. Thank You
Jeff

Sounds like you have checked the ground just as you are supposed to.

Where the wiring hasrness came from does not matter. It only matters how it is connected. There were not a lot of changes from 1970-74 anyway.

My meter 'Beeps' during continuity tets,(diodes). I've used Fluke and OTC and those meters dont 'beep' unless a continuity test is performed. I've never seen meters that beeped during resistance tests. Jeff do you have the settings on the funny looking upside down "U' which is the symbol for Ohms.(resistance) Or is it setting on the >I ?? Also can you post a pic of the engine bay? In particular the firewall, alternator and next to the battery.

Here are the photos you requested. I hope they are clear enough for you to identify the wiring to each component. When I check the OHM's, the symbol looks like an upside down "U". If there are any questions about either of the photos, please post them.

Thanks,
Jeff

I would re-check the wiring from the alternator to the voltage regulator. Do you have a wiring diagram? Another thing is it looks like the negative terminal isnt fully tightened because it looks like the wrong sized terminal. Make sure the terminals are tight.

I will check the neg. terminal I hope that's it. I have checked the wires from the alt. to the regulator and they are checking OK. I have a friend that has Challenger parts and I was thinking about getting a engine harness from him. I will get one from a 73 or a 74 Challenger so I don't have to get a conversion kit. Yes I found a wiring diagram off the net. Could the amp gauge in the dash be bad? I was told that the amp gauge could be bad. So I took the wires off the factory gauge and made extensions so they would reach my aftermarket gauge. When I did this there was no power. The dome light or radio wouldn't come on and the car would not turn over. I don't if this tells you anything but I hope it does. I had to stop working on it tonight because I have to be at work early in the morning. But I will start again tomorrow. Thanks for your help.
Jeff

I replaced the negative terminal and wire to make sure everything fits tight. I cut all the tape around the wiring from the alternator to the fuse box and everything checks OK. The green wire from the alternator runs to the voltage regulator and the blue runs to a 3 way splice. One wire runs back to the fuse box and the other runs to the ballast resistor. I started the car and let it idle at about 1000 rpm's and it was 18 volts at the battery. I unplugged the voltage regulator and the voltage dropped to 13. I don't know but shouldn't the voltage went up? I need all of your help if you know anything that will help.
Jeff

Disconnect the battery negative. Place a lead on the battery positive terminal and on the "batt' post on the alternator stud. What is the resistance? It should be near zero. If there is high resistance you have a problem with either the alternator or the wiring you just checked.

I am sure it must be the way the regulator is wired.

On the back of the alternator there are two field wires on spade connectors.
It does not matter which way around these to wires are at the alternator.

However at the regulator one of the field wires (the green one) goes to one of the pins on the regulaor. The other pin goes to ground somewhere. The case also needs to ground.

The blue field wire goes to a switched ignition source and NOT the regulator. Make sure this wire gets full battery voltage and does not go via the ballast resistor or something.

I will try this with the lead from the battery to the alternator. I feel that there is a problem with the wiring like you said. I have looked at diagrams from the internet and I don't see any difference. Is there any way you could tell me how the wiring should be going to the regulator? Is there any way that the ballast could be wired wrong? This shouldn't have anything to do with overcharging. I want to thank all of you for your help.
Jeff

I think that maybe the problem. Like I said the blue wire from the alternator runs to a splice coming from the fuse box. One wire goes to the Ballast resistor and the other goes back to the regulator. You said it should not go to the regulaor but could you tell me where the blue wire from the voltage regulaor is suppose to go? I have a good feeling this is my problem THANK YOU.
Jeff

I think the diagram I was looking at was wrong.
I found a better one.

The blue wire does go to the regulator. But still make sure this one is getting full battery voltage as this is the wire the regulator senses.

I ordered a new wiring harness from a company called Year One. I told them that the regulators that I have been buying was for a 74 challenger which all were electronic ignition. They told me these would not work so I ordered one that they said would work, Wish Me Luck.

Jeff

Same regulator all years. But there is definitely something wrong with the way you are wired up. Hopefully a new harness will correct that.