Positive about that?

[chrisk]

I have a trickle charger, that has been stored for years. I dug it out, without the lead that plugs into the bike. That part had black and red wires
The directions on the unit say there is a red wire for + and black for -.
Well there's not anymore, it has two black wires. How can I determine, which is + and which is -?

 

[Tippie]

A digital multimeter set on DCV will show a figure for volts with the meter connected as intended (red wire in + and black in -com), and a - sign before the volts figure if you have it the wrong way. However these new modern super intelligent things don?t deliver volts unless there is a battery attached, hopefully yours isn?t so smart.

 

[chrisk]

Ok, Google is faster than you blokes! 

According to the mfr, it has a polarity protection circuit to avoid nasty things happening if 'someone' connected the wrong way around.

So, 'someone' will take a 50/50 guess. What can go wrong? 

 

[chrisk]

Except for you Tippie. 

 

[chrisk]

Multimeter didn't like that, shows nothing either way, red light isn't on the charger either. Maybe it needs to be connected before it turns on-on.

 

[Terry Dymond]

Do you have an old battery lying around, if so, try it on that with the multimeter across the terminals.

 

[chrisk]

All sorted, Tippie was right. Once powered up I tested the power with the multimeter and when arse about there was a big fat - before the reading value.

She's on trickle feed now. red light is on and beer is cold.

 

[Laverdalothar]

while you are at it (and I am sure you thought about it already or have it done), I'd put some red tape around the positive wire...

 

[chrisk]

I didn't, but I hooked it up to a plug that goes into cigarette lighter socket, that charges from the trickle feed and means I can charge my phone and other stuff from the bike.

 

[Dellortoman]

It's a keen smoker that has a cigarette lighter fitted to his bike. 

 

[chrisk]

Scuze the dust. On charge.
Now ........................ where to mount the ashtray?

 

[Davo]

On the Laverda and Guzzi I have fitted one of these fused connectors https://www.rapidonline.com/yuasa-ypcringmc-motorcycle-plug-to-ring-connectors-with-fuse-18-5234

The battery charger cable connects with no worries about what is +ve or -ve except for when you connect the colour coded ring connectors to the battery.

 

[Dellortoman]

Never seen a tacho that says "FULL" at 14k revs before. Probably means you should check that you have a full wallet before revving it that far

 

[henry]

while you are at it (and I am sure you thought about it already or have it done), I'd put some red tape around the positive wire...

Whilst blindingly obvious to some, this has to rate as "Recommendation of the Week" - maybe that would make a good thread title, Lothar!

 

[sonomalaverda]

It's a keen smoker that has a cigarette lighter fitted to his bike. 

I am on a family holiday in the Southwest of the US ( literally where John Ford made all his Westerns ).

We visited the Four Corners = where Arizona, New Mexico, Colorado and Utah meet.

Whilst visiting the monument there a pair of huge Harleys pulled up. One ( I swear ) had a coffee cup holder and coffee cup in it attached to the handlebars.