Custom ECU/Body wiring, need help/clarification

[87_7MGTE]

hey everyone, im wiring in my new ECU (megasquirt) and i need some clarification about what some stuff means.

in the following i am referring to here: http://www.supras.nl/index.php?option=com_content&task=view&id=34&Itemid=50

if you look at the defogger relay (M1 pin 11) it says signal is switched to mass. What does it mean when the signal is switched to mass?

also on connector M1, pin 2, it says "Plus for backup light switch". what is Plus?

thank you

 

[figgie]

signal swtiched to mass = singal is switched to ground. BUT unless you replaced the harness going to the rear of the car. Why are you even looking at the rear. The engine harness is independant and seperate from the other harnesses.

 

[jetjock]

hey everyone, im wiring in my new ECU (megasquirt) and i need some clarification about what some stuff means.

in the following i am referring to here: http://www.supras.nl/index.php?option=com_content&task=view&id=34&Itemid=50

if you look at the defogger relay (M1 pin 11) it says signal is switched to mass. What does it mean when the signal is switched to mass?

also on connector M1, pin 2, it says "Plus for backup light switch". what is Plus?

thank you

Looking at the other instructions infers "mass" is ground. Seems to be a Kiwi term. Just another example of two countries separated by a common language. Even though he's not a Kiwi IJ can likely enlighten us on this

Another tip off it's ground is how the defogger switch pulls that line low (to ground) for the defogger relay and also so the ECU can change the target idle speed. Used to offset the load from the alternator when using the defogger. Since (I don't think) the MegaSquirt does ISC that may be a moot point but I don't know.

I assume "plus" is merely + 12 vdc.

 

[87_7MGTE]

thanks for the help guys, i figured "mass" either meant +12v or ground. figgie, i was just using the defogger as an example, because it was the closest to the top that used the term mass. i have replaced my whole engine harness, and the M1, B1, and B2 plug all came out along with the ECU plugs.