My alternator charges 6.8 amps when sitting idiling and about the same when I rev a little. When I use the headlights the gauge goes to discharge about 5 volts but the alternator is still putting out 6.8 volts. I think I have halogen headlight bulbs. Is there a way to correct it. I have a 35 amp, one wire self exciting alternator which is basically new. Is it going to leave me on the road ? Will I be okay with no night driving ? Thanks Wayne
32's didn't have them, but most newer cars do for acc.'s to keep from pulling to much juice. There was a good thread on them about a month or two back. I'll see if I can find it.
Your explanation is confusing, first you say amps, then you say is still putting out the same volts. When you say the gauge is showing discharge, that implies an amp gauge in the dash with a zero center and shows charge or discharge, is that correct? If it was a volt gauge, there should be no negative on the scale, just start at zero and go up. A relay will make no difference on what load an accessory pulls, it will just carry the load and take it off of controls or switches that are not rated for that much current, and yes your lights would probably benefit from running off of a relay.
The volt meter used on the alternator itself shows it is charging 6+ volts. the amp meter on the dash shows it is discharging.
Where is the output of your alt wired to? Is it connected to the battery? If it is disconnect it and connect to one side of the amp meter. If it still showes discharge connect to the other side of amp guage.
Does the amp meter show to the positive side with the lights off when revved a little. The reason I am asking is if it was wired backwards it would show discharge when actually charging. To know for sure watch the amp meter while the starter is turning the engine, should show discharge. Edit: Also make sure the belt is not slipping, have to be quite a bit tighter than a generator.