74HC157n mux problems

[Jay23]

Hi All,
I am using quad 2:1 to control 3 relays. as the input signals to the mux are comming from 2 different uCs.
The mux has these config.
pin 15 is Enable
pin 1 Select

IN: 2,5,11 and 14
OUT: 4,7,9 and 12

The problem is when the circuit is turned on the relays are switching constantly On and Off.
The relays are SPST type. Enable and Select are grounded.

I am using the config as in the function table for this chip.
appreciate some help on this matter.

 

[barry]

Without a schematic there's no way to answer this. Your screenshot is useless. If you have Select grounded, then why even use the mux, why not just direct connect the signals?

 

[Prototyp_V1.0]

He has already got an apropriate answer in another forum.