>on this in the last day. There IS a ballast resistor. For a 74 it
is a
>resistive wire that is run in the wiring harness from the 4A fuse
in the
>fuse block to the coil. If you measure the resistance from the +
side of
>the coil to the 4A fuse, it should be 1.35 ohms.
============
Ditto for my '75.
============
If that wire is broken,
>then that WOULD explain why the car would start and run ONLY when
the ign.
>switch was in the "start" position.
>
>When the ign. switch is in the "start" position, the ballast
resistor
>is cut out of the system. Thus allowing for a hotter spark. (For
more
>info. on this see my article on electrical - ignition on the web
page.)
>
>I would think that if this wire is broken, you could mount an
external
>ballast resistor on the fenderwell and run a "normal" wire from the
>fuse block to one side of the resistor, and then from the other
side
>of the resistor to the coil.
===========
This is the hot ticket since the OEM wire normally increases
resistance over time and affects performance.
===========
>
>Change of subject. 74's have an interesting item. They will NOT
start
>unless the seat belts are buckled. (This is what that large
whiteish
>plastic box is on the pass. side floor board.) This was NOT the
case
>in the 75s. The 74's also have a relay on the top, rear of the
pass.
>front fender well. There is a "red" rod or button sticking out.
If
>the car will NOT start, you can depress the button inside this rod
with
>the ignition on and the car should start.
>
>I've spent about 5 hours trying to get the 74 I've been working on
to
>start. I had it running great for the last month. All of a
sudden,
>a couple of days ago it would not start. I was not getting and
power
>to the start side of the starter solenoid. I replaced the ignition
>switch to no avail. Today, I managed to figure out how to by-pass
>the seat belt control module. The only problem is that I've also
>by-passed the park/neutral safety switch. So not the car will
start
>in any position on the transmission.
>
>Anybody played with the wiring for the park/neutral safety switch?
>There are 3 wires going to it. The switch is supposed to signal
>both when in park/neutral and when in reverse - it activates the
back
>up lights. There is a connector on the firewall right next to the
one
>for the wiper motor. This is the breakout for the wiring to the
>park/neutral safety switch. The center wire goes hot when the ign.
>switch is turned to "run" and "start". What I haven't figured out
>is where the wire goes when it goes back into the main harness. I
>have to find a way of getting that tied into the by-passing of the
>seatbelt safety lockout so the car will NOT start except in park/
>neutral.
=============
I know this was standard on Ford's around '74, and I assume other
makes. Have you looked at a wiring diagram from that era for a
possible clue?
GM
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