headlight relays

bearwolf64 said
I would like to have one relay run for both the high and low beams

If you use only one relay to control the whole headlamp system, then all it takes is one failure (a faulty connection, a dying relay, etc.) to kill your whole headlamp system, leaving you suddenly 100% dark. Much safer to control the low beams with one relay and the high beams with another relay.

I 'm also trying to use the exsiting wrining that is in the car.

A proper relay installation does not require you to cut or remove any of the existing wiring; you just use the existing wires to trigger relays and build a new power path for the headlamps from the power pickup point to the relays and from the relays to the lamps.

I can power the block of relays from the hot wire that is current running to the ammeter and bypass the ammeter.

But this does not address one of the main weak points, which is the connection of this wire where it passes through the bulkhead.

I would like to keep everything under the dash.

Much better to leave the entire existing headlamp circuit intact and put the new power path and relays up front, as close as possible to the headlamps. This makes for the shortest (lowest loss, most reliable) headlamp circuit. You can easily hide the relays under the battery or in any of several other places at the front of the car.