12V supply question

hobieboy · 03-09-2005, 07:28 AM

Hi,

I'm trying to find a 12V source inside the car that supplies voltage only AFTER the car is started. Not before and NOT during cranking.

Is there such a spot I can tap into?

thanks...

RoninLB · 03-09-2005, 02:15 PM

in the cabin is plenty, check the ign sw terminals. in the eng comp is the 3 fuse block that you can select the correct one from.

hobieboy · 03-09-2005, 05:08 PM

Ronin,
The 3 in the engine compartment is active when the engine is running, but its also active when I crank the engine, I believe? What I try to avoid is any potential voltage spike when I crank...

For the passenger compartment, any idea which pin I can tap into on the ignition switch?

thanks...

RoninLB · 03-09-2005, 09:38 PM

Quote:

Originally posted by hobieboy

For the passenger compartment, any idea which pin I can tap into on the ignition switch?

ok.. I used a circuit off the ign sw to trigger a Jacobs Accuvolt that feeds my amp. Look on the wiring diag and you'll see a terminal that's not hot when starting but goes to power after start. The radio feed should also be available.

If the Accuvolt had voltage to turn on when starting then the starter ground current draw would seek out the Accuvolt ground and crash it. The 911 starter ground is the unspoken villian if your modifing or adding elec's. More so than other cars because of the placement of battery and engine. The starter and alternator ground complicates mods imo.

911pcars · 03-09-2005, 11:45 PM

This is a case where an inexpensive investment in a digital multimeter would make your task easier. The back of the ignition switch has several positions that are ON with the ignition ON. If you don't want to venture this far, you can branch off of the wire that supplies voltage to the radio.

Sherwood

hobieboy · 03-10-2005, 05:48 AM

Ronin, thanks for the explanation. Looks like I'll have to take a 2nd look at the wiring diagram. The wiring on my car is screwed because the PO did a number of wacky things, so my radio circuit doesn't seem to be fed off the original factory way.

Sherwood - I do have a multimeter, just being lazy here

I found a good # of sources if I only want power after the ign switch is in ON position, but I also want power to cut off when the starter is on... a little more complicated unfortunately.

RoninLB · 03-11-2005, 01:55 AM

Quote:

Originally posted by hobieboy

Ronin, thanks for the explanation.
Looks like I'll have to take a 2nd look at the wiring diagram.

Sherwood - just being lazy here

... a little more complicated unfortunately.

Explainations make the job less complicated or the explain wasn't good enough. The only thing complicated may be asking the related question.

Being lazy

hobieboy · 03-11-2005, 09:04 AM

Ronin,
You're the man!!! So I just need to look for the X-pin for my application!

Why doesnt the factory wiring diagram as clear as this

RoninLB · 03-11-2005, 06:51 PM

Quote:

Originally posted by hobieboy

Why doesnt the factory wiring diagram as clear as this

use a test light and turn the key to each position. I think the sw is numbered differently than the pic?

each circuit is presented in an overview. The specifics is a story unto itself.

Pelicanheads have experienced different faults and unintended consequences in these circuits that is not written about in any book. We share our solutions and understanding here in a data base that enhances that experience.

kinda like trying to understand what make a female tick.