Warning guage

[56rag1914cc]

I picked up this guage at a swap meet and want to hook it up to my oil idiot light. Not being the electrical guru...i tried grounding (from where you see red wire) and then wire to idot light from one of the bulbs on the guage. It has two connections for two bulbs and a ground. Any ideas on how to wire this sucker up?

[Marc]

Come again? You want to use this as an oil pressure warning lamp?

It's intended to be a dual bulbholder for a temperature warning system (Mercedes-Benz, probably) where an inline engine has a sensor or a V-8 has one on each bank, wired in parallel. The bulbs are wired in series between Term 15 (ignition) and Term D+ on the generator, so that when you switch on the key the lamp glows dimly, proving that both bulbs are working. When the engine is started and voltage comes up on D+, there's not enough difference in potential to light them so it goes dark. If that was all there was to it, it would effectively be nothing more than a generator warning lamp - a dim one

Term WK (the red wire) isn't ground - it comes in to an isolated mounting block which houses the two bulbs. When it's grounded by the sensor(s) there will be full voltage across each bulb (on a running engine that's charging) so the lamp glows brightly.

So, if you just want to use it as an oil pressure light you could connect the red wire to the ignition switch output and hook up the wire from the sensor to one or both bulbs.

It could also be used as the ultimate "idiot" light by connecting one lamp to the oil pressure sender and the other one to the charging system warning lamp wire...but when it lit you'd have no indication of which problem is present, so I'd only use it in addition to (not in place of) the two stock warning lamps.

[56rag1914cc]

Come again? You want to use this as an oil pressure warning lamp?

It's intended to be a dual bulbholder for a temperature warning system (Mercedes-Benz, probably) where an inline engine has a sensor or a V-8 has one on each bank, wired in parallel. The bulbs are wired in series between Term 15 (ignition) and Term D+ on the generator, so that when you switch on the key the lamp glows dimly, proving that both bulbs are working. When the engine is started and voltage comes up on D+, there's not enough difference in potential to light them so it goes dark. If that was all there was to it, it would effectively be nothing more than a generator warning lamp - a dim one

Term WK (the red wire) isn't ground - it comes in to an isolated mounting block which houses the two bulbs. When it's grounded by the sensor(s) there will be full voltage across each bulb (on a running engine that's charging) so the lamp glows brightly.

So, if you just want to use it as an oil pressure light you could connect the red wire to the ignition switch output and hook up the wire from the sensor to one or both bulbs.

It could also be used as the ultimate "idiot" light by connecting one lamp to the oil pressure sender and the other one to the charging system warning lamp wire...but when it lit you'd have no indication of which problem is present, so I'd only use it in addition to (not in place of) the two stock warning lamps.

Exactly, use as an additional oil pressure warning! The ignition switch output...the same output (#30) that runs to my coil?

[56rag1914cc]

Works like a champ!! Even tested with my Berg temp dipstick.

[Marc]

...The ignition switch output...the same output (#30) that runs to my coil?

Term 30 is the DIN standard designation for B+ (battery positive, unswitched/always present). The ignition switch output to the coil (and accessories on a VW) is Term 15. Ignition switch output to the starter solenoid is Term 50.

http://en.wikipedia.org/wiki/DIN_72552
http://www.thesamba.com/vw/archives/inf ... l_2003.pdf

[56rag1914cc]

As always you come through for me Marc, thank you so much for your time and patience. It is very appreciated.