Ignition switch

[decoupe]

Arrrrrrgh. I needed to get that out first.

I've had an intermittent problem with the ignition switch in the start position - it won't start. I tested it by checking all other functions in the switch (everything fine) and then turn the key to the run position and hot wired from the battery to solenoid. Started fine every time therefore it's the switch which is a sealed unit so ordered a new OEM replacement from a reputable source. It is the correct part and should be straight forward installation. Right.

Put in the new switch, turned the key and the # 7 (green wire run position) fuse pops. Accessory (violet wire #10 fuse) is fine and the starter (black wire) turns over. Replace fuse check all connections, try again and same thing happens.

Put the old switch back in and everything works (including my intermittent start position). Put the new switch in and this time everything is perfect so button up the steering column cover and neaten up the wiring. Turn the key and pop!!!!!!!!!!

Unless someone can come up with an alternate conclusion I'm convinced the new switch is defective. When I get the knot out of my back from the inverted electrical position the CS is famous for I'm going to put the old switch back in and pray that it works - even intermittently. I'm down to my last 8 amp fuse.

Doug

 

[Honolulu]

don't get mad...

Doug, suggest you bench test one or the other switch. I suspect you'll find they are both okay, which won't make your next job any easier...

What it surely sounds like is that you have a dead short somewhere to ground. Of course, the most common cause would be a spot where the insulation has been rubbed raw, and copper conductor is exposed. The bare spot might not happen right at the switch, or even within 6 inches of the switch... might be required to trace power all the way back to wherever it comes from.

But if it isn't the switch itself (which I doubt) then it has to be a dead short bare wire. I wish you luck finding it. Recall that the seat is removeable by just 4 little 10 mm boltheads. I'm helping a neighbor doing under-dash work on two '57 Tbirds and it is a comparative joy not to have that damn bench front seat taking up all the cockpit space.

 

[decoupe]

I'll definitely get it tested as I don't want the supplier to take an undeserved hit. What I find baffling is that the old switch has completely different issues (intermittent start problems) from the new (blowing the run position fuse).