12v flasher relay, 3 prong

[DiscoJen]

Started installing the new wiring harness, yay! As part of converting from 24v to 12v I need to replace my turn signal flasher with a 12v unit.

Is this a Rover specific part or will any 12v 3 prong flasher relay work?

While I'm at it and trying to learn...how does a flasher work? I am assuming one prong is from fuse block to the flasher relay for power. Then one prong for Left and one prong for Right. Works kinda like a coil, the input from the signal stalk will complete the circuit and send the flash/power back to the appropriate Left or Right bulbs??? School me.

Thanks!

 

[siiirhd88]

The typical turn signal circuit using a three prong flasher is incoming power to one prong on the flasher, outgoing power to the turn signal switch on another prong, and the third prong going to a single dash indicator lamp that lights when either side turn signal is flashing.

The old style (non electronic) flashers use a bi metallic strip as a contact surface. (like one side of the strip being tin, the other side copper) When cool, the strip is flat and the contact surface is closed allowing power from one prong to the other. As the current flows thru the bi metallic strip, the strip heats up and bends due to the different metals expanding at different rates. When the strip bends enough, the contact opens, the turn signal lamp goes out, and the bi metallic strip cools.....

When you actuate the switch, power goes thru the flasher unit to the switch and out to the selected side turn signal bulbs.

Two prong flashers work the same way, except the dash indicator lamps are supplied by the same circuit as each side's turn signals.

Bob
'02 Disco II SD
'80 SIII 109
'75 SIII 88 V8
'68 SIIA 109 V8

 

[kevin-ct]

I just picked up a flasher from Napa for about $4.00

 

[DiscoJen]

Thanks guys, I love a good local purchase.