knock gauge

[GOT JCE]

I installed a few new gauges in my pod holder and after reinstalling my knock gauge it won't light up brightly anymore.It was hooked up exactly as before but the green led that lets you know it is on is very dim and all the other lights stay on also..What could cause this?I checked all the connections,checked to see if it was being shorted and the only thing I see that can be wrong is that the wire that comes from the computer is showing 12v.Can that be right?There are 3 prongs on the back of the gauge.1 is a ground,1 is power and 1 is the computer connection.All three are in the right spots.Can the gauge have gone bad in a week?If anyone has any ideas please share your thoughts.Thanks,AJ

 

[Dabigguy]

You may have a bad ground, the ground wire may not be large enough for the additional gauges, the power wire may not be large enough gauge wire to supply all the gauges either.

 

[GOT JCE]

knock sensor

You might have something there.I went from a fusion boost gauge with led lighting to an autometer with a big ol light bulb and combined all the grounds on to one wire.I will try using better wire on the ground side,or finding seperate grounds.But why was the knock gauge showing 12v from the ecm wire.Does that sound right?

 

[Dabigguy]

You shouldn't have 12v on that wire. Check to see if you have 12v on the other wire also. Both wires shouldn't have constant voltage. I am not sure what voltage should be on the signal wire from the ECM, but it shouldn't be constant. Can you check the voltage on both wires? Maybe even check the signal wire on the millivolt scale. I'll check my paperwork when I get home.

 

[Dabigguy]

I don't know if you have the instructions, but looking at the rear on the gauge, the left terminal (A) is ground. (B) is 12V (C) is your signal wire from ECM. Hope this helps.