hi i have an 85 e 350 i changed the old alt,external reg to a 1 wire tuf stuff its charging just fine 14.5 at battery ,the amp gauge doesent work shows discharge with lights on can i do any thing to get it to work? thanks

 

Have you ever noticed this factory amp gauge working before you changed the alternator and were concerned about the charge? I ask because most of them don't work normally, and the ones that do don't give any useful info. I personally would not waste my time trying to get it to "work".

But this is how it's hooked up. In the original harness charge wire that left the alternator, there is a special piece of wire inserted called a shunt. When current passes through this shunt(it's really a very small calibrated resistance) a small voltage is generated across it. There are two small wires soldered on either side of the shunt, and these are what go in and drive the factory ammeter. So if you did not use the original factory alternator wire, it's not going to work.

If your new alternator is a high output job, you probably can't use the factory wire because it's too small, so you are stuck anyway.

The best thing you can do if you are concerned about the well being of your van, is to get a aftermarket gauge set and mount it under the dash. It will give you real temp and oil pressure readings with real world numbers, and also get the set with the voltmeter, and that will tell you if the alternator is charging or not.

 

thanks for the info,ill probbly look into an gauge set for it,thanks again