BCDD wiring question.

[Chickenman]

Simple question. Is the Yellow wire that goes to the BCDD a switched +12V connection. Don't have a BCDD any more, but I may want to use that connection for something else if it is Ignition On +12v. TIA.

[Zed Head]

I think that it is switched on when the key is on (pretty sure it's the under hood click I hear when I turn the key on) but it switches off above 10 mph.  Checking for voltage above below 10 mph is part of the testing protocol.  Emission Control chapter.

 

If your car had AC but doesn't now, the AC compressor wire is in the vicinity.  They get mixed up occasionally.

 

You might also short or bypass the amplifier in the cabin.

[Chickenman]

Thanks. The switch off at 10 mph renders that wire useless for my purposes.  I'll dig around and find another source.

[Captain Obvious]

You looking for something up in that corner of the car? The power wires to the ballast might suit your purpose.

[FastWoman]

Or the power to the accessory air control valve or thermotime switch.  Or the power to the injector drop resistor assembly beneath the master cylinder.

[Chickenman]

Or the power to the accessory air control valve or thermotime switch.  Or the power to the injector drop resistor assembly beneath the master cylinder.

That just gave me a thought. I don't have the Ported Vacuum switch installed ( Federal Dizzy 1976 280Z) . That should have +12V with ignition and I believe that it is ground switched.

[Zed Head]

One more goofy 76 switch is the "top gear switch" that actuates the vacuum advance control solenoid.  It runs through the transmission switch though so you'd need to extend the wire from the switch location.

 

Looks like they used it to power a lot of small loads, like the hazard switch light and various gauges.  It's fused though.

 

 

 

 

[Chickenman]

One more goofy 76 switch is the "top gear switch" that actuates the vacuum advance control solenoid.  It runs through the transmission switch though so you'd need to extend the wire from the switch location.

 

Looks like they used it to power a lot of small loads, like the hazard switch light and various gauges.  It's fused though.

Yes..that's the thingy I was calling a Ported Vacuum Switch. I'll find it's " Hot " feed somewhere.

Edited May 30, 2015 by Chickenman