I have a 73 dart, 225 with the electric ign. I just swapped my 2nd alternator in the car in the past 2 months. It could just have been a poor part. However, I put the new one in at it reads +40 while cruising! While warming the meter reads low. Once warm at idle it rests proper. It has a new battery that tests good and a new coil. What am I overlooking

1. Put in a new voltage regulator
2. Stop buying "remanufactured" alternators, which are junk.

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Too many people who were born on third base actually believe they've hit a triple.

Can you please provide info on where we can purchase new alternators? Last I remember it was an occational seller on ebay.

They're kind of a "catch as catch can" item these days. They do go by on eBay from time to time. I have varying stocks myself.

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Too many people who were born on third base actually believe they've hit a triple.

Royceflo,

I had a similar problem. Here is a thought....
Take a look at the wiring harness from the alternator to the first junction into the main harness. It unplugs right behind the valve cover. It's only about 4" long. After unraveling the tape you may find burnt and shorted wires wear they have been wearing against the valve cover. I found 3 wires that had gotten really hot and melted together with the alternator wire. One was the oil guage causing it to flicker at all rpms, the other was a coil wire. The wire enamel had melted off and were allowing them to short against each other.

The fix is to save the modular connector and buy some new brass connectors and wire. It took about 2 hours to crimp and soilder everything up and get it re-wraped and installed. A little conveluted tubing wouldn't hurt either to keep the abbrassion down. I used some dipped/coated clamps as standoffs from the valve cover bolts to hold the wire bundle. That way it will not rub against any metal. With the new wire bundle everything works fine now.

On the alternator, take it to the "Rebuilder". It is a business that just rebuilds starters and alternators. They carry all the stuff to rebuild them.
You can find them sometimes near Marina's or near industrial areas. I am not sure if the high amp chrome units Summit and Jeg's sells are new or not. Maybe Dan can give us an update on them. He should know.

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Aggressive Ted

http://cid-32f1e50ddb40a03c.photos.live ... %20Swinger


74 Swinger, 9.5 comp 254/.435 lift cam, 904, ram air, electric fans, 2.5" HP2 & FM70 ex, 1920 Holley#56jet, 2.76 8 3/4 Sure-Grip, 26" tires, 25+MPG

Thanks all. The 2nd replacement alternator was the original that was sent to a rebuilder as I didnt want to go with a reman. Also, I'll do as you suggested ted and check the wires but, wouldn't ground wires pull less volts or neg. Not have it run at +40. Also, the regulator has been replaced as well. I am going to have the alternator tested later today as well just to double check, as well as my battery.

Don't forget to check the regulator ground carefully. If a stock regulator isn't grounded at all, there won't be any charging at all, but if it is partially grounded it can think that the system voltage is too low and keep turning the alternator field up.

The sheet metal screws tend to corrode a bit over the years and poor grounds are not uncommon; using the wrong screws also can make for poor grounds. I finially cleaned the holes, used conductive grease and put in rivnuts to avoid the problem.

Also, I'd check for a damaged FLD wire between the alt & the regulator and a broken FLD lead insulator at the alt. The '73s feed IGN power to one FLD lead and controls the current in the (spinning) field winding (which induces much more current in the (static) stator) by connecting the other FLD to ground via a transistor inside the regulator. A short in the low side FLD will max the current in the field winding and hence max the main alternator output.

A quick test is to just unplug the regulator (you can do this safely w/ the car running) - if it still charges, your problem is the wiring; if it stops charging, it's something to do with the regulator.

A good friend of mine once ran his car with it charging full-tilt like yours; when he went to check the battery's water level, it exploded in his face. Be careful.