Stone Cold Dead

[Buzz]

While removing the alternator to install a new high volume water pump, I accidentally grounded one of the terminals against the cylinder head. I had stupidly neglected to disconnect the battery beforehand and now the entire electrical system is dead. The battery still shows a strong charge, but that is it. No lights, horn, instruments and no igntion. I understand that grounding the alternator can destroy it , but does it sound like I fried something else as well? Bear in mind that I still have the Chevy engine in the car and the alternator is a GM 3 wire unit. I have already ordered a new alternator, but in the meantime (about a week) shouldn't there be some sign of life in the rest of the system? What should I look for first? Any help will be deeply appreciated.

[pgermond]

Sounds like you most likely fried the fusible link..... that's where I would start. Mine is located on the battery side of the starter solenoid.

[Buzz]

Thanks Phil - I will check it out and report back on the results.

[Buzz]

Well, I checked the fusible link in the hot line going to the starter and it is fine. So the question now is; can I expect to bolt on my new alternator and problem solved, or is there likely to be damage elsewhere? All fuses are ok, no sign of any burned up wires in the engine compartment or behind the dash. Can a shorted out alternator alone halt all power in the rest of the system?

[Naumoff]

No, I don't think so.

Power from battery to starter rely. and power to fuse block from there.
Charging wire from the Alt. connects at the same point. Check your battery cable from the battery to the starter solonoid and the power wire from the solonoid to the fuse box. Also check the ground from the battery to the frame.
It still sounds like what Phil said.

Buzz,
Did you load test the battery or just put a volt meter accross it?

[pgermond]

Buzz,

Using a volt/ohm meter you should be able to track down where the "open" is. Follow the steps Tony outlined..... start at the battery side of the starter solenoid looking 12V. Tony also had a good point - check for a solid ground.

[JeepSnake]

Buzz,

Do you have a battery disconnect switch? If so, try switching it OFF, then back ON and see what you get. Dad's car has a circuit breaker built into the battery disconnect. We discovered its existence quite by accident right after putting the car together (at the start of a parade, no less!).

If you do have a circuit breaker in the switch that's tripped, it will "feel" just like resetting a circuit breaker in your house electrical panel. The switch will sort of feel like it's not quite ON, but it's not quite OFF either. Switching it fully to OFF, and then back to ON will reset it.

Hope the answer is this simple!

[Buzz]

Thanks for the replies, guys! I checked the battery and the connection at the starter with a voltmeter and both read over 12 volts. The battery negative to frame ground connection is good. I guess like y'all suggest I'll just have to start tracing wires from the starter forward until I find the fault. Zach, I only wish I had a battery disconnect switch that had to be reset! Thanks again and I'll update as soon as I (hopefully) track it down.

[Buzz]

Quick note: on my way through the garage, I grabbed the multimeter and verified the following:

* Full 12 volts to the starter
* 12 volts at both ends of the fusible link connected
to the starter.
* 12 volts at the alternator terminal.

Good frame ground verified at several points. Didn't have time to check any further.

[Naumoff]

Buzz,
You might want to change the ignition switch.
Serious........Check the ignition switch as it turns the power on to everything else.

Do you have power to the ignition switch?

A dead/flat battery will show 12volts too, that's why I asked if you did a load test on it.

My first lab experiment in electronics was a lesson about this. We had full voltage across a battery but couldn't figure out why the light would not come on. Dead battery.

[Buzz]

Didn't get a chance to actually work on the car today, but I decided to study the ProDesign manual that came with the wiring harness. To ease my pain tracing circuits tomorrow, I sketched up a schematic based on the info. The wires are numbered & colored as in the manual and the lightning bolts indicate points that a 12V reading has been verified so far. Question: Do I have the current flows as indicated by the white arrowheads correct? (Note: starter is a GM unit with no external solenoid)

http://www.clubcobra.com/photopost/data/500/wire_schematic.jpg

[Naumoff]

Buzz,
Check to see if you have power to your ignition switch and any power to your fuse box.

[Buzz]

Well, I went diggin' and found a couple of things. Firstly, I had a few details wrong in the schematic I interpreted from the directions in the manual, so here is the corrected version:
http://www.clubcobra.com/photopost/data/500/medium/wire_schematic1.jpg
Then I learned that positive feed to every electrical component except the starter on a car equipped with an ammeter must go through the ammeter and then on to ignition to coil, fusebox, etc.
I decided to run a jumper wire from the downstream end of the fusible link in wire #27 off the starter right to the "BATT" terminal on the alternator. Well hello there - everything (except the bypassed ammeter) worked like a charm. The car fired right up and actually seemed to run a bit smoother than before along with a startlingly crisp response when I blipped the throttle. First conclusion is that the fault exists somewhere between wire #27 and the ammeter since there was no power to ignition or fusebox prior to the jumper. Secondly, this exercise appears to have exposed a weakness in the system somewhere between the fusible link ,ammeter and the alternator because of the very noticable improvement in idle quality and throttle response after the bypass. I also noticed a possible ground issue in my cooling fan circuit as the fans ran intermittently when everything else was working perfectly. Back to the garage to start tearing into that portion of the harness to see the condition of wire #27 and check the ammeter then wires #39, 41 and 25. I'm sure I'll find the problem somewhere in that group. I'll keep updating...Thanks again for all the help.

[pgermond]

Buzz,

As an aside - what brand of gauges are you using? BTW - nice diagram :)

[pgermond]

Buzz,

What's the latest - any progress?

[weaver]

Phil, if I lived wher he lives ( paradise ) I would have gone to the beach and forgot about my wiring problems.

Alan

[Buzz]

Lol! Actually, I've been a bit busy as well as waiting for the new alternator to arrive. I got a chance to install it yesterday and of course the system is still dead. I probably won't be able to spend any more time on it until tomorrow so I'll update then. I'm pretty confident that I'll get to the bottom of it - just hoping it's not the ammeter that's shot - it would be much faster to replace a wire or two than to wait another week for a new gauge. Phil, I have Stewart Warner instruments. I see that the diagram pics have disappeared. They're located in my Club Cobra gallery and they should reappear when that site is back up and running.

[Buzz]

Well, it's a lot worse than I had hoped. After pulling the dash, I found power coming in to the ammeter acc. terminal through wire #27 from the starter but no power at the "batt." terminal which feeds wires 25, 39 and 41 connected to the starter, fusebox and alternator respectively. This indicated a fault in the ammeter itself which I bypassed by connecting #27 directly to 25, 39 and 41. Everything (except the ammeter, of course) seemed to come back on line and the car started up and idled beautifully. Since I had installed a new high volume water pump, I decided to let it idle for a while with the fans off to see how fast the temperature came up. Well, I soon realized that either the new pump was doing a mighty fine job or the temp gauge was not working. Unfortunately, it turned out to be the latter case and then when I turned the fans on, they ran for a second and stopped (manual - no thermostat switch). Wiggling the wire bundle connected to the fan switch got them going again but they would stop and start at the slightest touch of the wires. "Ok", I thought; What next? I turned on the headlights and the "tail" fuse in the box promptly sparked and blew leaving me with no taillights but brakelights and headlights work as well as turn signals and hazzards at all corners except the left rear. Horn, dash lights and tach are fine. My first guess (hope?) is maybe a damaged ground wire in the dash harness somewhere. I will try to trace the fault(s) tomorrow and let y'all (we say that down here too, you know) in on what I find. Time for a swim.

[Naumoff]

Buzz,

Fly me down for a week and I will help you fix it.:D

[Master]

Buzz,

I had the same problem with my fans as well earlier this year and it turned out to be my fan switch, I would wiggle the back of the switch they turn on and then off randomly. I have seen what I thought one issue turn into 3-4 issues when chasing circuits but it sounds like you are on the right track.

[Buzz]

Thanks, I think I have a spare switch - I'll try swapping it out and see what happens.
Hey Tony; no problemo buddy, but do you think you could do me a teeny lil' favor and throw a Southern Automotive Super FE and a TKO600 in your suitcase on the way down? If you sneak it through customs unchecked, it sure would save me a bundle on duty and taxes.

[Naumoff]

Buzz,

What you do is find someone( engineers) who are bringing in a bunch of equipment to do work.
List your stuff as tools and in come the goodies.:D

Send some bids my way for plumbing and Mechanical work and I hook you up.;)