so i was wondering which wire in the boost sensor plug is the ground? a guy that i met said he had similar problems about boost cuuting out at 4k and he said he regrounded his boost sensor and it helped out alittle but also he had a different wiring pin out than mine and it was the same car 87 t2 so i dumb founed and i reedid the ground wire that he done on his and now my boost gauge (in dash gauge) dosent work so in thinking thats the reference wire but there is 2 pins with 2 brown wires in each ands then a bigger black wire and the solo brown that i reground??

info would be lovely plus i dont wanna get a volt meter and i work all weekend and week long so not alot of time to fool around with it

 

Like most ground wires in the car, it's black. The FSM wiring diagrams has sensor pin-outs and wire colours. If you don't have the FSM, click here and download it in PDF format for free.

 

What is the build date on the car?
If it's a later '87 model, Mazda had already fixed it.

http://fc3spro.com/TECH/FAQ/3800.html

See bottom of that page.


-Ted

 

Sorry, but my 86 and 87 cars, turbo and non turbo, have the ground wire as a brown/black wire as the ground JUST like the 87FSM describes it. IF you find two brown/black wires in the connector coming from the same socket, then the ground problem has been already addressed by the factory.

Around 88 the Mazda factory got all goofy footed and changed the ground wires to pure black. They screwed the pooch when they did that.

The brown/black wires are found in the top row, right next to the black/white wire.

The output wire is brown/red, reference voltage wire is brown/white and the black/white wire is battery voltage.

Next time you describe wires, please note if the iwre has a stripe on it. The ground wire is Brown with a Black stripe.

This only applys to series four car and only the early versions.....the good version.

And while here, the extra ground on that boost sensor was not to take care of a boost sensor problem but a afm problem. It was easier to get to the common ground wire (brown/black) at the boost sensor rather than the afm plug. That info came from the trouble shooting bulletin that is almost free and online at ALLDATA.COM.

 

my vin is before that

 

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