Duraspark findings, correct?

[Kurt Combs]

I have spent several hours researching Duraspark II systems on the net. I am installing one in a 72 F-250 with a 460. Here is what I know and what I am not certain about:

Both the donor truck (1977 F-150) and the 72 F-250 both have resistance wires to the coil. But the 72 has 1.3 to 1.4 Ohms resistance and the 77 has 1.05 to 1.15, this is my main area of concern. The reason is someone, in one of the posts I read, had the resistance wire overheat using the stock 72 pink wire on a Duraspark. Most posts say it is fine to use the stock 72 coil wiring. I am leaning towards using the stock wire even though it has slightly more resistance.

The pink resistance wire seems to be connected to the printed circuit that is part of the gauge wiring. So removing it seems like a bad idea. Maybe the gauge wiring connects directly to the ignition switch and does not feed off the pink wire, I can't tell from my research and following wires under my dash is a real challenge.

The white wire can feed off the "S" terminal on the start solenoid or the ignition switch as long as it is hot only when starting the engine. It can't feed off of the "I" terminal if the stock wiring is used as it would be hot all the time with reduced voltage feeding back from the pink resistance wire.

The Duraspark unit needs power when the engine is starting and running, so that should feed off of the ignition switch and from what I can tell the wire that would be best is blue on wiring diagram, but red with blue on my truck.

The Duraspark likes a cooler environment, so I will look to see if there is room for it on my firewall inside the cab.

Any and all comments appreciated. Kurt

[Kurt Combs]

And it seems there is a blue wire going through the firewall that goes to a throttle on some trucks, but not mine, could be used for the Duraspark red power wire and my electric choke.

[basketcase0302]

The pink resistance wire seems to be connected to the printed circuit that is part of the gauge wiring. So removing it seems like a bad idea. Maybe the gauge wiring connects directly to the ignition switch and does not feed off the pink wire, I can't tell from my research and following wires under my dash is a real challenge.

I believe I can help with this part Kurt as i just replaced my resistance wiring a few weeks ago. If you drop the ignition switch out of the dash-I believe you'll see where the gauge wiring ties into the resistance wiring pink right at the female spade terminal at the switch plug. But I don't think that much difference in the resistance would matter to the box. I'd run it for a few weeks then pull a plug and see what story the plug tells.

[Kurt Combs]

Thanks for the info Jeff. I wired it today and I will put some power to it tomorrow night to see if I got all the colored wires going where I think they should. I was pretty straight forward, just took a couple of hours slicing and connecting things. I fully expect the wiring to work as is, but then again you never know when working on an old vehicle.

[basketcase0302]

Love me some Duraspark Kurt! I still have the entire harness from both my 76' EB and my 79' F series here. Might still put a Duraspark in someday.