GM HEI conversion questions
If you mean switching power to the ignition system, "it depends."
Many of these cars are now suffering the effects of damage to connectors, switches, and the bulkhead connector, AND with added stuff on the car, the ignition switch was never designed to carry some of those extra loads -- fuel pumps, example.
So IF your bulkhead connector/ ignition switch is in good shape and IF you are not suffering voltage drop through that circuit, there is no real reason to run a relay.
I did, though for several reasons, and also am no longer using factory wiring in my car. I found a "junker" underhood box out of a Voyager which has relays and fuses enough for expansion. What's in there now is relays for:
ignition/ charging
fuel pump
high and low beam relays
antitheft
like this one:
It mounts handily on the fender to the rear of the battery, and power from the starter relay stud goes to the two studs at bottom right.
Also, Bussman makes similar relay / fuse boxes which you can configure in all sorts of ways
If you mean switching power to the ignition system, "it depends."
Many of these cars are now suffering the effects of damage to connectors, switches, and the bulkhead connector, AND with added stuff on the car, the ignition switch was never designed to carry some of those extra loads -- fuel pumps, example.
So IF your bulkhead connector/ ignition switch is in good shape and IF you are not suffering voltage drop through that circuit, there is no real reason to run a relay.
I did, though for several reasons, and also am no longer using factory wiring in my car. I found a "junker" underhood box out of a Voyager which has relays and fuses enough for expansion. What's in there now is relays for:
ignition/ charging
fuel pump
high and low beam relays
antitheft
like this one:
It mounts handily on the fender to the rear of the battery, and power from the starter relay stud goes to the two studs at bottom right.
Also, Bussman makes similar relay / fuse boxes which you can configure in all sorts of ways
