allenr
Gold Member
- Joined
- Nov 28, 2006
- Messages
- 399
- Location
- Barossa Valley, South Australia
- Tractor
- Duetz DX3.70, Fendt 305LSA,260S & 205P,Kubota B6100E & 3 x B5100E & RTV900, Caterpillar 428C
I recently bought two dashboard warning lights to replace a blown alternator warning light on ny Kub B5100 (second as a spare). They happened to be LEDs and I figured that was probably a good thing, for longevity.
Fitted the first - didn't work, fitted the second - didn't work.
Played around with both on the bench, connecting them to a charger 12V supply.
Eventually discovered that Pos & Neg have to be one way and one way only - then they worked!
That was news to me.
Fitted it back on the tractor with correct polarity and it worked, but then stayed on even when the alternator was charging.
Disconnected the spades to the warning light and connected them to a test light. Discovered that the negative disappears when the alternator is charging and so, the light should go out.
Re-connected the spades to the light and then, with the alternator charging, disconnected just the negative lead - then the light does go out despite the fact there is no negative in the lead.
It's got me baffled. Finally reverted to a larger incandescent globe left dangling out below the dash.
Fitted the first - didn't work, fitted the second - didn't work.
Played around with both on the bench, connecting them to a charger 12V supply.
Eventually discovered that Pos & Neg have to be one way and one way only - then they worked!
That was news to me.
Fitted it back on the tractor with correct polarity and it worked, but then stayed on even when the alternator was charging.
Disconnected the spades to the warning light and connected them to a test light. Discovered that the negative disappears when the alternator is charging and so, the light should go out.
Re-connected the spades to the light and then, with the alternator charging, disconnected just the negative lead - then the light does go out despite the fact there is no negative in the lead.
It's got me baffled. Finally reverted to a larger incandescent globe left dangling out below the dash.