switched +12V source that doesn't cycle while cranking the engine?

[G.T]

this has baffled me for a while, but i forgot about it till i came across an old video of a problem with my Autometer nexus fuel pressure gauge (you just have to watch the first 15 seconds):



notice how back when i first installed my gauges, i wired the switched power source somewhere that didn't cycle while the engine is being cranked, which meant the gauges would initialize once and stay on till i turn the car off and take the key out (which is perfect)

however since i've rewired everything a while back, my gauges and all interior accessories (radar detector, etc) turn off while i crank the engine, which is fine for most accessories except the nexus gauges that have to initialize twice everytime i start the car.

i remember looking everywhere for a that elusive point that didn't lose power during the engine start up, but couldn't seem to find it!

can anyone spare me from checking every wire inside the cabin again?

 

[Riptide]

Will be hooking up a wideband soon and also was wondering about this.

/subscribed

 

[viciousride]

Wiper Motor? For my wideband I used a 5A Add-A-Circuit tapped to the wiper motor fuse which is 12V switched power.

 

[bigray327]

See here. I'm pretty sure I used "C". I have a fuse box with 8 slots running from there to my glovebox, where all of the interior stuff is wired.

 

[bigwilly43729]

Painless wiring fuse block. Problem solved.

 

[G.T]

See here. I'm pretty sure I used "C". I have a fuse box with 8 slots running from there to my glovebox, where all of the interior stuff is wired.

that's where all my stuff is wired now too!
C is a +12V switched source that also turns off while the engine is cranking

 

[dysan]

I used C and my Innovate wideband does not turn off when starting the car. I wonder if your battery is getting weak and when you start your car it looses enough voltage that your gauge is turning off.

 

[G.T]

certainly not a battery issue as the problem started since the rewiring.. and is still there with a new battery

i wonder if something is screwed up in my SJB

then again i know the switched source normally does cut off while the engine is cranking (like the factory head unit) so i think i'm just tapped into the wrong source.. not sure

 

[Boozshey]

 

[bigray327]

Do you have water leak issues? The world might be pissing on your SJB.

"C" works for me reliably, but if you really want to get hard core about it, you could dig up the WOTbox installation instructions and see where it ties into the PCM, then spend the next 15 hours soldering into that.

 

[G.T]

no water leaks.. never even spilled a coke in there

like i said, interior switched sources are supposed to power off while the engine is cranking to preserve power.
you'll notice even your dashboard resets, etc..

anyway i guess i'll wait for the weather to clear up a bit, and spend a few hours with a voltmeter

 

[slammed 06]

We tied our power source for my wideband into the passenger side kick panel area. There is a junction power distribution block located over there. I also used it for power for my intercooler pump. I will take some pics if you need me too just let me know.

 

[G.T]

We tied our power source for my wideband into the passenger side kick panel area. There is a junction power distribution block located over there. I also used it for power for my intercooler pump. I will take some pics if you need me too just let me know.

that's where mine are tapped, but if it's not too much of a hassle even a blurry photo will help me narrow down the target
thanks in advance!

 

[slammed 06]

k give me a few and I will take one.

 

[slammed 06]

The pic with the screw driver pointing towards position 4 is the one I used for constant power when cranking over. There are very few power sources like this short of running wire all the way to the battery and then ya have to deal with it being on all the time.

 

[concours_greg]

True ignition, remains hot while cranking: white/yellow - ignition switch, 7 pin plug, pin 1

I have attached a .pdf of all of the wiring info you will need on this car. It is for a 2008, but most should be close.

 

[G.T]

Thanks man I really appreciate it.. Will check this line out

 

[INTRUDER]

See here. I'm pretty sure I used "C". I have a fuse box with 8 slots running from there to my glovebox, where all of the interior stuff is wired.

I used "C" to power my Autometer Cobalt boost gauge. works perfect ever time now.

 

[G.T]

True ignition, remains hot while cranking: white/yellow - ignition switch, 7 pin plug, pin 1

I have attached a .pdf of all of the wiring info you will need on this car. It is for a 2008, but most should be close.

i had all this info in the wiring diagrams section in the service manual, but the file you posted is quite comprehensive and a lot simpler.. thanks

 

[MikeVistaBlue06]

certainly not a battery issue as the problem started since the rewiring.. and is still there with a new battery

i wonder if something is screwed up in my SJB

then again i know the switched source normally does cut off while the engine is cranking (like the factory head unit) so i think i'm just tapped into the wrong source.. not sure

If your starter is "dragging" it will pull a lot more current than normal and this will cause the terminal voltage of the battery to drop lower than it normally would. This would in turn cause lower voltage readings on anything that remains "hot" while cranking.

Just a thought...

HTH

Mike