Re: [ihc] Coil Voltage?

[John Hofstetter <hofs@xxxxxxxxxxxx>]

on 3/22/04 1:09 PM, George B Humphrey at xgbhx@domain.elided wrote:

> 
> 
> Brainstorming here. The I terminal on the Ford solenoid gives full
> unballasted battery current during cranking. Could I use that as a
> trigger source as well as the tap I have now without frying a circuit?
> How do Fords use the I terminal in conjunction with their normal run
> circuit?
> 
> George H.
> 72 Scout II

OK, George, here's the scoop, I hope. I called my son, the Delco solenoid
expert, and I think he straightened out my age-weakened brain.

The Delco solenoid only supplies coil voltage from the R terminal and only
then to points distributor systems. No points, no use for the R terminal. I
guess we knew that.

The S terminal is only the activation for the solenoid. That's why you
inserted the Ford solenoid in that circuit.

He says that a big part of the fuse panel is "on" in both the start and run
function of the ignition. The other part of the fuse panel is for the
accessory stuff. 

Put a test light or a meter on the circuits coming from the fuse panel and
choose one that is off when the switch is off, and on in both start and run
modes. This wire should go out and trigger a relay which is fed from a lead
from the hot side of your Ford. Now the relay can supply full switched power
to the coil and whatever else needs to be switched. I supply my field lead
power on the alternator from this point.

I THINK your Pertronix (pretty sure) system has to be protected by a
resistor and I think the specs say that it can use the reduced voltage ALL
the time. So the lead from the new "trigger relay" supplies the ballast with
12 volts and the ballast resistor supplies whatever. A different wire from
the trigger relay supplies the power for the ECU.

I think this will do it.

John Hofstetter