Joe Flanagan Posted April 3, 2011 Report Posted April 3, 2011 I was running my engine today and I noticed that the ammeter needle was jumping back and forth rapidly from charge to discharge, pretty far on either side. I let it run for a while to see if it would settle down, but it kept on doing it. I searched the archives because I thought I read a post about this some time in the past, but could not find it. I know that one possibility is I could have the wires to the back of the gauge switched around, but I don't think so. I'll check that out tomorrow but I wanted to ask if anyone had any other ideas. Quote
greg g Posted April 3, 2011 Report Posted April 3, 2011 Didn't we talk about this in regards to making sure you VR was well gounded??? Did you do the frounding the field terminal test??? Quote
Joe Flanagan Posted April 3, 2011 Author Report Posted April 3, 2011 Yes and yes. When I brought this up before, I performed the ground test and the needle jumped over to the charge side and stayed there. It was erratic at first but settled down. All the activity was on the charge side. The difference now is the needle is moving without me grounding the field armature and it is jumping to both sides of zero erratically. So it seems like it's a different situation. Would your answer to my earlier post also apply to this? Quote
greg g Posted April 3, 2011 Report Posted April 3, 2011 (edited) the test would. What kind of shape are your gennerator brushes in?? Is the VR new or an older one? Any posibility that there is a wire somewhere that might not be connected to its appliance that may be inadvertantly grounding Edited April 3, 2011 by greg g Quote
oldodge41 Posted April 3, 2011 Report Posted April 3, 2011 Joe, over the years my ammeter has done that a couple times, usually after it has sat for an extended time. Each time a couple "taps" on the generator with a brass hammer has settled it right down. I suspect my brushes hang up a little and the taps loosen them up.................Tim Quote
JBNeal Posted April 3, 2011 Report Posted April 3, 2011 it sounds like a grounding issue...had a similar condition when the internals on my fuel gauge fell apart in my '48 Quote
Joe Flanagan Posted April 3, 2011 Author Report Posted April 3, 2011 Thanks for the responses. My generator is rebuilt with new brushes and the voltage regulator is new. After I posted this I read somewhere that sometimes new brushes will take some time to seat and until they do, a jumping needle can be the result. I also read that my belt could be loose. I will explore the ground issue, since that seems to be the consensus. I just want to be certain I'm not going to burn anything up. Thanks. Quote
Don Coatney Posted April 3, 2011 Report Posted April 3, 2011 If your ammeter is serious about jumping it may be too late for counseling. Quote
Joe Flanagan Posted April 3, 2011 Author Report Posted April 3, 2011 Oh, that would be just like me. Don, maybe this is just one of those ammeters that can't be reached. I expect to get under my dash to discover a tragedy one day. Quote
T120 Posted April 3, 2011 Report Posted April 3, 2011 Joe,You've probably already polarized your generator since servicing..but easy to do...Just thought I'd ask. Quote
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