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Posted by: FourBlades Mar 30 2015, 08:28 PM

I have had several ignition switches fail in m 1973. I am on the third "new" ignition switch in 4 years. I think these are a repro part and not up to the original standards.

What usually happens is either the ACC does not switch on so the fuel pump does not run or the starter does not switch on leaving me stranded.

Are these 3 position switches or just 2?

Does anyone have a diagram for how to wire a switch for the ACC and a starter button? I notice there are 6 terminals on an ignition switch module so I assume this is not simple.

I would keep the key just for unlocking the steering column and maybe rig a second, hidden switch for the fuel pumps.

So far my engine has been very reliable and it has always been electrical problems in the relay board (now thankfully removed by Joe O'Brien from Series9) and the stupid ignition switch that have caused my car to not run.

Thanks,

John

Posted by: screenguy914 Mar 31 2015, 01:53 AM

Most ign. switch wear and tear is due to current flow in the "Start" or "Crank" position that energizes the starter solenoid. You can reduce ign. switch wear by installing a separate momentary switch (push button, toggle, etc.) to energize the starter solenoid. Use the ignition switch only in the "ON" position to activate all other circuits (fuel pump, ignition, radio, lights, etc.).

Here's a link describing the circuit for a 911 (generic for most cars):
http://members.rennlist.org/911pcars/RemoteStarter.htm

Hope this helps,
Sherwood

Posted by: WLD419 Mar 31 2015, 03:57 AM

Hello John, here's a diagram of what I did for mine, the button only works when the
key is ON , and this fits under the dash, I also use a hidden pump switch (ground based for my fuel injection) ,
if you stall the motor while driving just push the button , no need to turn the key off and back on again, I hope this helps Bill D.

Posted by: jim_hoyland Mar 31 2015, 06:40 AM

Does the yellow wire going to the original ignition switch require a diode to protect it when the button start is used ?

Posted by: WLD419 Mar 31 2015, 08:54 AM

I didn't put one in my setup ,I don't see a need for it , the yellow wire coming out of the
switch goes to the starter solenoid , the key switch will still operate the starter ( if it's still good/ working properly)
you have the added benefit of the button ( which I prefer to use / it takes a load off of the secondary part of the key switch, which
is the part I think goes bad ) maybe I'm wrong about the diode , but I haven't had a problem so far . Bill D.

Posted by: Bartlett 914 Mar 31 2015, 09:50 AM

I think this is a good case for the "hot start relay" A simple relay located by the starter. The ignition switch pulls the relay and the relay contacts engage the starter. Look at the size of the wire that pulls the starter solenoid. It is a pretty big conductor. Your switch needs to handle all this current. Put the load on a cheap relay and save the load on the switch

Posted by: patssle Mar 31 2015, 10:45 AM

I'm using this push button...it handles the amps easily http://m.delcity.net/store/Heavy!Duty-Push-Button-Switch/p_8065.

Posted by: FourBlades Mar 31 2015, 12:12 PM

How much load is on the accessory part of the switch?

This can be a significant amount if the lights are on.

I don't want to ever have to take apart my ssteering column to fix this again.

John

Posted by: FourBlades Mar 31 2015, 12:23 PM

Double post.