I have been posting in the main board under URGENT. So, I thought I would ask in here.

It started with my ignition not working after connecting a jumper from the distrib to the battery. Anyway I change the switch and it starts just fine. But, when I shut it off it blows the 50amp fuse. I guess what ever it is is what burned up the ignition switch.

Im guessing I have a short somewhere. I dont know where or how to check it. Any help would be appreciated.

Thanks
Tony

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obnoxious 67 camaro under construction. TH350/383 stroker w/ aluminum Edlebroc RPM heads,cam, and carb. Guldstrand mod, Hotchkis 600lbs springs. Next Hotchkis swaybar and disc brakes.This is a "Daily Driver" that still needs A LOT of work.

Tony, Get an ohm meter and Isolate the ing. wires then check them to ground, if you get a reading than thats the wire thats grounded, and should be replaced. If your meter reads clean, you might try the same thing with a megger. (this will also check your wires only with a load). sounds like you have a dead short that will blow a 50 amp fuse.... I don't know if this will help but good luck Mike

Should I pull each wire and check for ohms?

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obnoxious 67 camaro under construction. TH350/383 stroker w/ aluminum Edlebroc RPM heads,cam, and carb. Guldstrand mod, Hotchkis 600lbs springs. Next Hotchkis swaybar and disc brakes.This is a "Daily Driver" that still needs A LOT of work.

Tony, I am not and expert with DC, but yes you are checking for contunity. Isolate each wire ,to make sure they are not grounding out against anything metal, remember you are blowing a 50 amp fuse, must be something going directly to ground to do this.such as, bad insulation, pinched wire, burnt coil somewhere in the circut, etc...Mike

I pulled all the wires off the ignition and tested them. There is zero resistance for each one. Am I understanding that I should get some resistance or is this all wrong?

Please help,

Tony

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obnoxious 67 camaro under construction. TH350/383 stroker w/ aluminum Edlebroc RPM heads,cam, and carb. Guldstrand mod, Hotchkis 600lbs springs. Next Hotchkis swaybar and disc brakes.This is a "Daily Driver" that still needs A LOT of work.

This 50 amp fuse you keep blowing must be a Painless item. The standard fuse block doesn't have anything that high. I don't know what it is fusing. Maybe the inputs to the ignition switch and headlights. Does the fuse blow if you leave the ignition switch connector off?

Ive blown 3 fuses now and dont have anymore ill have to wait until I can go to the parts store.

Do you mean leaving the wire off of the ignition switch that goes to the ignition?

Tony

One of my peeves is to see the same thread in 2 different places. Kinda tough for everyone to contribute. Anyway. I assume that the 50 amp fuse is protesting the input side of both the ignition switch and the headlight switch. Harder to see when aftermarket wiring is used. Originally it was a red wire. If that's the case, disconnect the red wire or the entire ignition switch connector and see if that stops the fuse from popping.

Does the harness have a connector with all of the terminals in it for the ign switch, or, are You having to connect each individual terminal to each terminal on the back of the switch?

What I am trying to get at is that there is a terminal on the ign switch that goes to ground when the switch is turned to the off position. That ground circut is for the key buzzer and is on a 68 but I'm not sure about a 67. Maybe someone can clarify this. Or maybe somebody sold You a 68 switch???

I'm just kinda wondering why the fuse is blowing after the key is turned to off and I'm thinking that there is something wrong with the way the switch is wired. I'd verify that that is correct before I went anywhere else if it was mine.

Good Luck and as always just repost if You cannot find it. pics, schematics and any addl info is always good.

And like John said, keep the questions in one spot.

Sorry about the different post. I thought maybe someone might not read both sections so I didn't want to miss anyone who could help. Ill stay in the elec.

Anyway, my ignition switch is the kind where you hook up each individual wire onto it not a harness. The 5 wires are for: batt, sol, ground, acc, ign.

Im wondering maybe the new switch is bad?

Tony

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obnoxious 67 camaro under construction. TH350/383 stroker w/ aluminum Edlebroc RPM heads,cam, and carb. Guldstrand mod, Hotchkis 600lbs springs. Next Hotchkis swaybar and disc brakes.This is a "Daily Driver" that still needs A LOT of work.

What did you tie to the switch "GND" terminal? That terminal does not go to ground. The only thing that goes there is the wires for the TEMP idiot light. Usually a green wire.

That's strange that the fuse blows when you shut it off. I've seen starters try to pull 100 and some amps through alternate grounds, but that's a starting issue.

Don't feed it fuses. If anything install a test light where the fuse would normally go. Try disconnecting the alternator. I'm not sure how the painless system is configured, but shorted diodes in the alternator have been known to do weird things like this. The diodes basically short the battery to ground when the system isn't charging.

Anyway, the test light should give you a visual indication as you start disconnecting various circuits.

-dnult

First thing is to setup a test light. Remove the fuse and connect a 12vdc light in its place. have extra long leads so you can see it outside of the car. When you disconnect the shorted wire, the light will go out or go very dim. You have to have a major short to take out a 50amp fuse If its a smaller wire, the wire will generally smoke before a 50 blows. I would check the + junction behind the battery or the battery cable to the starter.



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69 convertible
LT1 4L60E

What do you mean +junction behind battery

Tony

I'm not sure if you years relays can be popped open like my old 71 t-birds but if so clean them out and if they are junky get new ones. Had a relay go bozo and ace some fuzes one hot sunny day. I didn't have the a/c functioning then I lost power windows thanks to a blitzing relay. The alternator is a lousy thing to do to good cutomers. Like mentioned the diodes going flaky will get you. Don't depend on a volt meter set to DC to pick up on AC coming out of alternator. You'll read battery voltage when the alternator is pumping AC out. The diodes are intended to staighten out the alternating current to only go into a positive and negative poles arrangement of DC. In other words the diodes go bad you'll be pumping positive one way then negative to the same wire. Ah heck it does it to all the wires it's connected to in that condition. Worse yet the voltmeter reads 12 or better volts and sears will sell you a new battey after the fancy machine says your battery is bad not holding amps. I guess if you can disconnect the alternator wires and retry blowing another dollar or so. Could be your starter relay or ignition switch with bad contacts. If it doesn't happen when cycling from off to on and back without starting "maybe" it's more prone to be a missalligned and sloppy relay mech that will ground to the case or that alernator dumping charges from it and the battery. You can get diode stacks and brushs cheap cheap instead of buying an alternator if that's the problem.

To let anyone know what has happened so far here it what the owner of the Camaro and myself found out. First, the problem has been fixed (at least for now unless this second switch goes bad).
It turned out to be a bad ignition switch of all things. When the ignition switch was turned to a certain spot the ignition terminal on the switch itself would internally short to the case of the ignition switch. With the switch mounted in the dash it would then blow the 50A underhood fuse. It would only short to the case when it was rotated and pushed in slightly and would not do it each and every time. We found this out by taking a meter with and audible beep that occurs when no resistance or very slight resistance is present and took one test lead off of the meter to the case of the switch and then took the other test lead off of the meter to each one of the terminals on the back of the switch. When the switch was rotated and pushed in just right the meter would beep and show zero resistance.
When we were troubleshooting the problem we had the switch out of the dash and everything checked out and worked just fine but after the switch was mounted it would blow the fuse. We also looked at the possibility that a wire was moving behind the dash from removing or reinstalling the ignition switch that could have been shorted to the chassis of the car but there were no problem there. I told the owner that if this second switch blows another underhood 50A fuse that he needs to look at a different supplier for an ignition switch (they may have a bad design or run).
One last thing that we learned, the Painless Wiring underhood fuse holder in this Camaro did not take any brand of Maxi-Fuse. It looked like it took a standard Maxi-Fuse but the ones I had from work and the other one from a local parts store would not fit the fuse holder. This holder has two molded in nothches that prevented two other brands of Maxi-Fuses from being inserted. You would think things would be standardized but this was not. I have not had problems with standard ATC or Mini ATC fuses fitting their particular fuse holders but I have never seen this with Maxi-Fuses or their particular holders. If you get extra fuses for yours make sure they fit before you find out they don't the hard way when your car is broken down in the middle of nowhere.

Have a Happy and Safe New Year.
Jim

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1974 Spirit Of America Nova (being restored), 1973 Nova Custom, 1977 Nova (Driver), 1973 Nova (Pro-Street someday)

Thanks for the update. We always like to hear how it turned out. We all offer suggestions, but like to know what the real issue was. Glad to hear you got it figured out. Aren't you glad you had a big fuse instead of a fusable link.

-dnult

Double post. Got hit with the "flood filter" which apparently allowed the message to post anyway.

-dnult

[This message has been edited by dnult (edited 01-01-2003).]

Yes it was the NEW ignition that had me at wits end. Thanks to everyone that helped.

Special thanks to Jim for coming over with his meter. I wouldn't have been able to figure it out with out him.

Tony

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obnoxious 67 camaro under construction. TH350/383 stroker w/ aluminum Edlebroc RPM heads,cam, and carb. Guldstrand mod, Hotchkis 600lbs springs. Next Hotchkis swaybar and disc brakes.This is a "Daily Driver" that still needs A LOT of work.