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View Full Version : Which one's toast...ignition switch or fuse box?



gogo34
04-07-2013, 07:49 PM
After fixing my little brakeline problem yesterday, I moved on to the new wiring harness. It's totally installed but, I'm having a problem with a couple of the systems. The headlights work, the tail lights work, the dash lights work but, I've got no front or rear flashers, no oil or ignition warning lights and no choke warning light. So, it appears everything powered directly from the battery is working and everything that comes off the IGN spade on the back of the ignition switch isn't. The IGN spade also powers the fuse box so it may be that. Is there a test I can do on the ignition switch to test the IGN spade? Anyone have any suggestions?

SafeAirOne
04-07-2013, 08:27 PM
Anyone have any suggestions?

Yup. Get a voltmeter, slap it on the "20v" setting and turn the key to 'run'. Stick the black probe into the black socket on the dash, then use the red probe to test for 12v-14v on the feed wire to the "hot in 'crank'/hot in 'run'" side of the fuse panel. Backtrack from there till you find 12v-14v.

This presumes that you have a SIII, as no model was specified. If you have a pre-SIII, just stick the black probe on a decent bare chunk of metal in the engine bay to ground it instead of the black socket.

gogo34
04-08-2013, 08:55 PM
Yup. Get a voltmeter, slap it on the "20v" setting and turn the key to 'run'. Stick the black probe into the black socket on the dash, then use the red probe to test for 12v-14v on the feed wire to the "hot in 'crank'/hot in 'run'" side of the fuse panel. Backtrack from there till you find 12v-14v.

This presumes that you have a SIII, as no model was specified. If you have a pre-SIII, just stick the black probe on a decent bare chunk of metal in the engine bay to ground it instead of the black socket.

After probing with the voltmeter, I followed a hunch and removed the 47 year old (1966 SIIa) ignition switch and took it apart. You'd be amazed at how dirty that little space had gotten. I cleaned all the contacts and reassembled it. Once I hooked it back up, it solved my original problem. Turns out the ignition switch was so dirty inside that it wasn't making the necessary contact when the key was turned. They are pretty simple devices but, you can see how a few years worth of dirt could cause a problem in such a small space.

SafeAirOne
04-08-2013, 09:14 PM
You must have one of those easy buttons from staples!

http://2.bp.blogspot.com/-sNgT43z0-SM/Tz_H1mtkUEI/AAAAAAAAAbk/A3s4LjGwjkc/s1600/easy-button1.jpg