I need a switched power source that is not interrupted by ignition. Installing electronic boost gauge.

Recommended Posts

The fancy step motor boost gauge that i bought needs an uninterrupted switched power source to function properly.  All the usual suspects are cut during ignition.  Does anyone know where I could find one?  Please let me know if you know.




Link to post
Share on other sites

I believe the big red wire to the accessory connector is on all the time. You could run a new line from the battery and install a fused switch so it only comes on after you've started the car. Back in the day I used a sunroof switch as a momentary switch for an air horn. Same could work for an additional fog light switch in the bank behind the wheel. 

Link to post
Share on other sites

The 850 has an accessory connector under the driver side dash; not sure if the S70 does? 

Look around under the driver's side dash until you find the Grn wire w/Ylw tracer.  Test it with test light or volt meter but it should be hot in RUN and START key positions. 


  • Like 1
Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.