Electrical drawing what does this mean

[spivvy]

i can read electrical drawings but i am confused about the bridge symbol or gate on the far right ,
electronic speedometer to gearbox speed sensor left wire B Y does that mean the circuit is opened or earthed as it is an ocillating variable or is it just a crap drawing

[spludge]

The speed sensor generates a square wave signal, thats what the symbol under the YN wire indicates. The BY wire is screened with the outer braid connected to earth.

The R wire on the speedo is also screened but with no external connection to earth, presumably thats taken care of inside the speedo.

Thats my interpretation anyway, hopefully there'll be someone along soon with a bit more expertise.

K

[chris_chim]

Sounds pretty accurate to me. Likely to only be earthed in one place otherwise earth loops are likely to ensue.