Looking for some suggestions on wiring the ignition to fuse panel. I know it depends on the current draw and how many overall circuits you have, but are you folks running the IGN and ACC wires directly from the switch to the fuse panel? or did you run it through a set of relays? I'm thinking that with a heater fan, fog lights, etc. that these all seem to add up to maybe 35A through the ign switch. Can the typical IGN switch handle this or is the recommendation to just have the switch drive the relays and then feed the fuse panel?
Accessories have been run through the ignition switch for years and we had a lot of ignition switch failures to go along with it. The main thing that a relay does is lighten the amp load on the ignition and other switches. before the mid 50's cars usually only had two accessory items. An am radio and a heater/defroster fan. Those didn't put much of a load on anything. The headlights didn't draw a lot of amps. A lot of us add a lot more electric powered items to our cars now. My ot 71 model truck used to eat dimmer switches every three months or so until I put a pair of relays on the core support to feed the power to the H-4 55-100 W halogens. It's been over a year with no switch or headlight wiring issues. When we install an HEI on an engine it needs a lot more amps to work properly and the switch might not want to handle those amps or we may not want to run a ten gage wire up to the switch. A relay lets us run ten gauge wire to the relay and then to the distributor and use a lighter gauge wire to trigger the relay.
I used a relay for the acc like shown in the referance, I have 2 6 fuse panels one for items I want to have power all the time and the other for the Acc. that uses a relay.
I ran all accessories that are "hot" with the ign on straight out of the stock '41 ford switch to the fuse panel. Have halogen headlights, heater, aux. rad. fan, C-D player and amp, vac. pump for wipers and it's been like that for 19 years with no problems.
I run relays for all high draw stuff. I just don't like the idea of a bunch of juice running through that switch. It's a lot of extra work, but I did it.
Here's a good article also, http://www.watsons-streetworks.com/current_topic.html I used the 70 AMP relay shown when I rewired I fried a switch without it because of extra circuits I ran,no problems since the relay was added.
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