g741.org

Hey there crew - I'm adding a 12 volt circuit to my 54 M37 to run a few things including an electric power steering module and a fuel pump. I'm wondering if anyone can recommend a decent place to access ignition on power from the vehicle that is also a higher amp circuit. I have a 60 amp voltage step down box I will be installing.

Thank you
Vince

for that much power, i would run a line from your key switch to a relay, and then use the relay to drive a dedicated, fused line direct from the battery to the converter. fit it all under the seat. that way when your key is on, you've got power, but you're not pushing 60 amps (well probably 30 amps, given that the 60 is likely output amps) through a 14awg wire.

Thanks Isaac! I really wish I knew more about wiring! What you are suggesting sounds great, but I have no idea how to rig it up. I was going to run a chunky main line into the converter and then a line out to a small fuze block and split it up from there ...

if you can read a wiring diagram i'd be happy to draw one up and post it here for you (or anyone else) to take advantage of.

Hello Isaac... Yes ... I can typically make sense of wiring diagrams - especially if the items are named (vs symbols).
What I have that I need to put in line is something like this:

Switched power source to 60 amp voltage converter. Voltage converter to sub fuze block.
Three items off sub fuze block. (That last part I can handle.... It would be the wiring of the items you described).
I would be grateful! I'm an auto body guy!

Also... The "stats" on the relay I would need to buy... As I don't know how they are classified...

I've drawn something up, and attached below. Can you link to the specific converter you bought? I'm assuming that when they call it "60 amp" they mean it can deliver 60 amps of 12V power, in which case the diagram and notes should be correct.

Here are a couple of links for possible relays, depending on how much you want to spend, and how "clean" you want it to look.

first, the Amazon option. If you go this route i would get the mating socket, which is sold separately. I like this less, because the socket only has 12awg wires on it.
Amazon Relay

Then there is the Waytek Option, which is what i would do if it were me. In the notes it lists the connector that is made to plug into the spade terminals for the coil.
Waytek: Bosch/Tyco # 0332002250

Thanks SO much Isaac! That's huge, and I think I can do it!!!
My only question is the battery.... I see the fuzed line going in.... But do I run the other lines from terminal to terminal and then to ground, or is that just the existent wiring and I only run the fuzed with to the hot terminal?

correct! the wire between the batteries and then the one to ground from the battery is already existent

If you want a 12-24 volt combination system to work flawlessly without a battery over-charge / under charge condition; install a Vanner battery equalizer. We have used this unit on many fire trucks that have heavy 12-volt accessory components operating constantly. It is the best thing going in my opinion, great success here.