Miata Mailing List: August 95, Message #35



   From: "Drake A. Daum" daumda@asc-en.wpafb.af.mil
Subject: Dash Switch Connectors & PIAA Wiring
   Date: Tue, 1 Aug 1995 14:35:45 -0400

   
  
     When I purchased my 1992/ B Package, it had three factory switch 
     positions to the left of the steering wheel.  One was taken up by 
     the factory cruise control, one by the dash light dimmer rheostat, 
     and the third was a blank panel.
          
     As evidenced by my article published in the Spring 1993 issue of 
     Miata Club Magazine, I was the first in the country to retrofit the 
     1993 power mirrors to a pre-1993 Miata.  I used the blank switch 
     position for the factory mirror switch.
          
     Later, when I added the PIAA 1000 driving lamps, I purchased them from 
     Brainstorm Products in Atlanta (1-800-779-3223) because they came 
     packaged with a Mazda factory fog light switch (a $30 value).  In order to 
     mount this switch in the dash, I removed the dash light dimmer unit and 
     remounted it underneath and behind the lower dash panel to the 
     left of the steering column, with the small thumbwheel control barely 
     protruding out from the lower edge of the panel.  I can access 
     the control if I need to by just sliding my finger along the edge of 
     the panel, but how often do you really need to change the brightness 
     of your dash lights?
          
     Now the three switch positions to the left of the steering wheel 
     all have factory switches to control the cruise, power mirrors, and 
     the PIAA driving lights.  Everything looks absolutely like it came 
     from the factory. I also encased all the added wiring under the hood in    
     flexible, black plasic cable conduit (sometimes called "wiring loom"),     
     packaged in 10 and 15 foot lengths at your local auto supply store. 


     There is no need to route any new wires through the firewall.  Mazda has   
     done this for you.  The connection you are looking for is a SINGLE wire    
     terminating in a small female bullet connector.  It is all by itself and   
     not part of a larger connector.  It is gray with a green stripe (as I      
     recall from memory).  It is located near the firewall and close to the     
     left fender area, outboard of the brake master cylinder.  It may be tucked 
     under some other electrical components and partially wrapped in black tape 
     or plastic sheathing.  You must use a male bullet connector to mate up 
     with this factory wiring.
     
     It is the wire that carries +12vdc from the factory dash switch to the 
     fog light relay mounted under the hood.  (This is the relay that you 
     must install yourself when you install your fog lights).  
     
     If you attach the factory dash switch directly to the connector on the 
     factory wiring harness behind the dash (this is NOT a connector for power  
     mirrors, which didn't apprear on Miatas until 1993), then power to your fog
     light relay will only be present if the headlight circuit is also turned   
     on.  To opt for autonomous operation, you must supply separate +12vdc power
     to the dash switch (LARGE red wire, if I recall correctly),instead of the  
     headlight circuit.  Be sure to use a source that is switched on/off with   
     the ignition to avoid accidentally leaving the fog lights on when you leave
     the car.  The 12v power to the PIAA relay can be obtained from the fuse box
     under the hood, near the right fender.  There is an unused position in the 
     fuse box if you don't have ABS brakes.  Use an insulated female spade      
     connector and route your wire up from underneath the fuse box.
     
     Before you attempt ANY electrical modifications to your Miata, ALWAYS 
     start by studying the Mazda factory wiring schematics.  To do 
     otherwise is just inviting trouble.

     Good Luck, and as always, YMMV !!

     Cheers,
     DRAKE A. DAUM, President
     Miami Valley Miata Club
     PO Box 33503
     Dayton, Ohio 45433-0503