MSefi.com read only forum (Jan.15,2018)

Would there be any problem with installing the relay board directly on the engine? i have a perfect spot right next to the coil on the drivers side valve cover. Just wondering how sensitive they are to heat, vibration, and coil interference.

Thanks,

Jason

By placing the relay board on the engine you'd be subjecting it to heat and vibration which are the enemy of electronics. Regardless of how much heat and vibration the relay board can hold up to, you'd be subjecting it to conditions that will eventually cause a failure. It's much safer to mount the relay board on the body or chassis and preserve the reliability of the device.

Also, if you clean your engine with water and solvents, the relay would be exposed to the liquids.

Cheers

Also mounting it close to the coil would pick up static from the coil.