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-   -   no electrical power - 70 GTO (https://forums.maxperformanceinc.com/forums/showthread.php?t=638471)

JD455 07-10-2010 03:56 PM

no electrical power - 70 GTO
 
Posted in another area - thought I try here as well. Thanks

http://www.forums.maxperformanceinc....ighlight=power

Old Goat 67 07-10-2010 04:13 PM

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Quote:

Help! Intalled the dash today and before I finished I checked for power. Everything worked fine. I disconnected positive and put the radio in. When I checked again, the positive battary terminal sparked a little and now no power. The two wires, yellow and gray, to radio was touching and might have been the cause. I checked all fuses and they are fine. Battery checked and fine. This happen twice before during normal driving and 8 months ago and a few days later just worked. No clue why. Could there be a fuse that resets itself?? See link below for past issues but almost a year ago. I would love to drive the car as its been sitting for a few months while I worked on the dash. Where should I check for 12v power to troubleshoot it? Checked and no power to fuse box.
My guesses would be either (1) bad connection in firewall connector, or (2) fusible links OR wire going open and then making contact again. Whichever will require some testing with a VOM.

Charles

stellar 07-10-2010 04:37 PM

I am leaning toward the fuse link. They can break or burn inside the insulation and not be seen. Sometimes the broken wires inside the insulation will touch making contact and even arcing themselves together, but a small electrical load or even a bump in the road can make them separate again. If you don't see any burn or open on the fuse link, you may try pulling on them. If they are bad they will stretch like a rubber band. If good it will feel like pulling on a regular piece of wire.

MescaBug 07-10-2010 04:40 PM

I had a random power problem a few weeks ago. Check my thread. Although its not the exact problem, it might help..

FWIW

http://forums.maxperformanceinc.com/...d.php?t=631642

JD455 07-10-2010 05:54 PM

I'll check the fusable link if I knew where to look. I have a wire coming from the alt that ties into four wires and goes towards the firewall. These wires, with the wires for the AC, are in a back plastic tube. There is a red one and three dark colred ones. I'll take off the black tube - does anyone know which wire its on and where - near the firewall or back over the manifold ? Also I should get power to the horn rely, unless the link is before it goes there????? Tomorrow I'll look at the starter again as it may arc there and ground out (the wire to solinoid is real close to the headers). The strange thing it works and than decides not to.

Old Goat 67 07-10-2010 06:05 PM

1 Attachment(s)
OK, the fusible links are marked on this drawing.

You have an intermittent open somewhere.

JD455 07-10-2010 06:22 PM

MescaBug, did you put in a fusable link? and if so, do you have a picture and where you got one. I have not checked yet to see if mine was messed with in the past yet.

Old Goat 67 - Thanks for the wire diagram!

JD455 07-10-2010 08:43 PM

http://www.forums.maxperformanceinc....=1#post4039839

Check out pictures and test I did. What type of fusable link is this

johnta1 07-10-2010 08:58 PM

Do you have 12 volts at the alternator post?

:confused:

JD455 07-10-2010 09:09 PM

see updated post in my link. No 12 v at post with wire from battery hooked to it. The wire is fine as I checked that unhooked. Does this sound like a ground issue

johnta1 07-10-2010 10:53 PM

You don't have 12 volts at the big red wire in this pic?

http://www.forums.maxperformanceinc....0&d=1278808823


If not, disconnect that wire and check the voltage on that wire.
(not connected to anything)

If no power, then the connection at the battery is bad.

JD455 07-11-2010 07:46 AM

I did that and disconnected I do get voltage in the red wire. Instead of the power going from the starter to the alt, it was changed and goes directly from the battery (large red wire shown in pic). I am going to check now the 10 red wire that normally goes from the starter to alt and make sure its not grounded. It must have been cut and still live since it is still connected (one of the 4 at splice)

JD455 07-11-2010 08:15 AM

SOLVED! The large red wire was corroded in the connection to the aftermarket positive battery cable. They was enough contact to get a voltage but not enough to get it to the car. I cut the large red wire, cleaned the connection and POWER to all! This explains messing with connecting the battery would fix it last year.

johnta1 07-11-2010 08:43 AM

Cool!

Glad you got it figured out.

:)

MescaBug 07-12-2010 10:52 AM

Yeah that's cool. Electrical gremlins are the worst...

JD455 07-12-2010 07:14 PM

Thanks. I could have spent weeks chasing that. It shows to start at the source - the battery- and work your way back. The connection looked tight and never would have thought it would be the problem but decided to check it out. Glad I did.


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