Newbe need some relay

Hi yall I'm in the process of wiring my efi up on my race car and I have a few question, right now I am wiring the outputs of my efi witch will trigger a relay to turn on say the fan or water pump now I am also going to have a 12v switch to bypass the ecu and turn on the fan or water pump manually. The ecu wire will be on 86 tab to act as a trigger. My biggest question is if I'm using a resistor type relay to prevent any fly back to the ecu would I also need a diode in line with the ecu trigger wire to prevent any back feeding when I use the switch to bypass the relay Here is a drawing of how I am thinking of wiring it up thank you for the help

In order to suppress back emf from the relay coil you would need to have a Schottky diode across the coil. The series connected diode is not required.

Ok so a resistor type coil won't work in my application and it would be a diode protected coil ? I'm not sure what a schottyk coil is

A 1N4001/L diode across the coil of your SPDT relay should be fine. https://www.the12volt.com/diodes/diodes.asp~wirewise~ Verify all wiring with your meter before making any connections!

Thanks wise now would the diode protected relays wire the same as how I have it in the drawing? And do you have a good source on where I could purchase these at?

You do still need the diode on the line coming from the ecu, and you want the switch connected to 86 also. Unless you are planning to use a 40 amp switch.

If your referring to bypass switch I have that hooked up to a fuse and relay

If I put a diode in line between the ecu output and and pin 36 wouldn't that be pretty much doing the same thing as as the diode between 85 and 86 just on the out side of the relay

The diode across 85 and 86 is needed to protect the ecu from the backlash created when the relay disengages. Is there a second relay that is not pictured?

Yes the bypass switch to by pass the ecu relay is also wired in with a relay as well