[Dhastings1954]

I have a 1998 RE Bullet iron barrel. Recently the ammeter has been doing strange things. Sometimes while riding at speed the ammeter shows negative. It will stay negative for a while and then pop back over to positive. Most of the time it is on the positive side where it should be.  Any idea what is going on? Bad connections? Battery seems fine. Do thes ammeters fail over time? Any help appreciated!

[Chasfield]

If it shows both negative and positive readings it is probably telling the truth. The most likely fault condition for an ammeter would be no meter movement at all due to mechanical movement failure, or it going open circuit - in which case electrical accessories would not be working as they all pull current through the meter.

Most likely you have an intermittent feed from the alternator. Look first for the cluster of bullet connectors which connect the first part of the cable coming from the primary case to the harness somewhere at the back of the engine under the carb. Break the connections and clean/reform/re-connect. This sorted my problem out before the depressing rats' nest of corroded wires in the headlamp prompted me to rewire the bike from scratch.

[Dhastings1954]

Thanks, good advice. I was thinking (hoping) it might be as simple as a poor connection. I will look there first. Would the connections on the ammeter itself be another possible spot to check?

[Chasfield]

It would be worth having a good look at all connections, including the ammeter, in the headlamp shell as, electrically speaking, that is a very busy place. However, your problem sounds more like a charging supply current issue related to the alternator or regulator/rectifier, as the meter flips from normal charging to battery draining rather than from normal charging to a no-charging condition - as you might expect from an intermittent ammeter to battery connection.

[Chasfield]

Original Bullet circuit diagrams seem to Google quite readily if you need one.

I'll link in my home-brew rewire thread. This includes my own circuit design, which is perhaps easier to read and may help your understanding of what is going on. My approach was to do away with the separate AC lighting system as a means of making the wiring spaghetti as simple as possible.

https://forum.classicmotorworks.com/index.php/topic,3064.45.html

[Dhastings1954]

 Thanks very much for this info. I will start by checking all the wire connections. That would be too easy, right? I installed a new clutch last summer so maybe I did something to the alternator, but haven’t noticed any issues until recently. I am suspicious of rectifier regulator. I noticed with your upgrade you did not use stock rectifier regulator? Are the stock ones OK? What did you use?

[Chasfield]

I think the stock reg/rec two-piece units are ok. The new one piece unit helped to simplify the wiring a bit, and I wanted to start off with fresh components, where possible.

The combined unit I used is a Wassell Power Module and is the single phase 12V 160 Watt version. It has worked well for 9 plus years now.

Googling "single phase motorcycle regulator" still brings up similar examples.

[Dhastings1954]

Thanks. I cleaned all the connections I could, which may have helped a bit....the needle is going farther into the + side than before, but a short ride demonstrated it is still jumping into discharge territory for short periods of time.
Think I will replace the regulator and rectifier with a combined unit. I see Baker Motorsports has one listed.

[Dhastings1954]

I changed out the old two part system with a new Podtronics single phase 12 volt 200 watt rectifier regulator. Seems to have done the trick. No needle fluctuations on the ammeter. Keeping battery charged too

[Adrian II]

Replacing a 20 year-old Indian rectifier and regulator? I think I would, too...

A.