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  • 1965 - 1973 Classic Mustangs -General/Talk-
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I Need serious help with my ignition switch...

  • Thread starter Thread starter Swede958
  • Start date Start date Sep 8, 2004

Swede958

Founding Member
Dec 17, 2001
712
0
0
Austin, TX
Sep 8, 2004
#1
  • Sep 8, 2004
  • #1
I've been trying to find out why my car keeps eating Optimas... so far 2 in the past 2 weeks, the last one without getting out of my driveway. I tried tracing back the wiring, here's what I found out.

With the battery out, I ohmed each wire at the solonoid . Three wires ohmed out to having continuity with ground. 2 are about 10-12ga, one black and one dark blue/green/off black. The other is a small, 18ga red one.

The wiring diagram I have lists one wire going from the solnoid back to a junction where is splits off into a black/yellow for the fuse box, a yellow for the ignition switch, and a non-color-listed to the headlight switch (later discovered to be black/red).

My car is wired with the two large wires going back to a junction, where it is joined by two wires, the yellow and the black/yellow. All wires have continuity to each other, which means when i ohm them they all have continuity to ground. Also, the headlight power is not to be found on this set of wires... so it is (N/A) on the diagram.

I ohmed my switch, and I'm getting continuity between ground and the yellow power wire with the switch off. My dad said this seems to be the cause of my problem with the switch shorting out and draining the batt in that there shouldn't be any continuity between ground and the power. And I'm not sure it's the fuse box or wouldn't I be blowing fuses all of the time?

I can elaborate on my wiring if needed. Right now I have a later model PMGR starter (on diagram) and a 3G alt (wired to BC Bronco's specs).

Can anyone PLEASE help me out with this, either confirm or deny or give other options. And does anyone know who carries a '70 ignition switch if this is indeed the culprit? No one seems to list prices.... if not, can a 71-72 switch be used instead?

Much thanks and gratitude to anyone who can help me out....
The Swede
 

pabear89

Active Member
Apr 15, 2003
2,126
0
46
High in the Hills of So Ca with the Voices in My H
Sep 9, 2004
#2
  • Sep 9, 2004
  • #2
First find out why you have power to ground on the hot leads from the Sol.
They are a direct drain on the Batt.
From you diagram, you have no hot lead to your fuse panel?
Recheck and get back to me.

PB
 

Swede958

Founding Member
Dec 17, 2001
712
0
0
Austin, TX
Sep 10, 2004
#3
  • Sep 10, 2004
  • #3
Thanks for the response PB,

I ohm out all of the wires connecting to the + side of the solonoid. Only two showed continuity to ground. They ended up joining together (factory) near the firewall. From there they split off into one yellow wire for the ignition switch and one for the fuse box (the black one with yellow slashes).

I checked the switch and it was grounding out (at least there was continuity between it's hot lead and ground with the switch off. I found a 71' switch at work that looks exactly the same as mine but with about 8" shorter leads. I'm gonna put that in tomorrow. That one didn't have continuity between hot and ground.

Thanks again for your response,
The Swede
 
R

Ronstang

New Member
Apr 4, 2004
1,294
0
0
Houston Texas
Sep 10, 2004
#4
  • Sep 10, 2004
  • #4
Check you alternator. If the a diode goes bad it can cause a direct drain on the system and it very hard to find unless you know to look for it.
 
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