Loss of power after about twenty minutes.

Postby turbocal » 29 Aug 2009 4:25

After about twenty minutes of driving, my tach jumps around, all of my lights blink, including the radio and eventually the car stops. A quick check of the battery and the volts show low, 8 to 9 volts. After a 10 minute cool down, suddenly I can see the volts began to rise on the battery, up to 12.2, and the car starts as though nothing is wrong. But this cycle repeats itself. I have a new alternator,, battery, and regulator , but I have the exact same problems before the changes. Can anyone help?

Calvin
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Postby dave-r » 29 Aug 2009 9:03

Strange one that.
The only thing on your list you have not changed is the coil. Is it getting hot?
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Postby Goldenblack440 » 29 Aug 2009 12:06

Sounds like you have a 'Thermal Runaway' problem. As a conductor heats up due to the current flow (and ambient temperature) the resistance increases, therefore current through it increases, and temperature increases more and the cycle continues. If a balance is not reached (eg if the conductor is not fit for the job, or has bad connection, corrosion etc) it will open circuit or burn out. Bad earths can cause it too.

i'm wondering if it is your battery at fault. they can get hot but i would not think after only 10 minutes. Could be a dodgey battery earth wire. Have you got a good earth from the engine to the negative, as well as to the chassis?
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Postby 71_DEPUTY » 30 Aug 2009 12:41

two places to check

1- check the bulkhead connections on the firewall- look for melted, brunt wires- look for the battery and the alt ones-heavier gauge wires.

next look at the ign. switch connector at the bottom of the column- again look for burnt, melted or loose connections!!!


John Mac

last- amp meter connections- nice and tight oh ya- check all battery grounds!!!!!
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Postby dave-r » 01 Sep 2009 9:28

Oh sorry. I miss-read the description of the problem. Been a busy weekend for me.
If ALL power goes off it has to the the cable going into the bulkhead connector to the ammeter. Either that or the ammeter itself. But it is usually the connection at the bulkhead.

http://www.madelectrical.com/electrical ... uges.shtml

Or a bad ground strap as already said.
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Postby turbocal » 02 Sep 2009 2:48

I will change the ground wire and see what happens. Besides the ground wire coming from the battery are there any other ground wires to check. Also I will check the bulkhead connections and other connections mentioned.
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Postby dave-r » 02 Sep 2009 7:24

Check the bulkhead connector FIRST. 95% of the time that is where the problem is.
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Postby turbocal » 05 Sep 2009 20:01

OK. I have checked the bulkhead. Everything seems OK. There are no burned wires. The ground wire is OK. This car also has a MSD 6AL, had it since I purchased the car , and an ACCEl Supercoil that maybe about a year old, and a Keisler 5 speed transmission for about two years now. I am trying to find out when exactly this problem occurs. I started the car and let it idle for about 35 minutes, raising the rpm on occasion, no problems. Then I shifted the car through the gears in my drive way and then the problem surfaced. Missing, lights flickering, and then the car kills. I check the volts on my battery charger with the terminals connected directly to the battery and it shows 12.5 volts. I then move the negative cable of the battery charger to another location and the volts show below 10. After about 10 minutes I can see the volts increase and then the car starts, but the lights are flickering, 30 minutes or so later the car starts with no problems, but the issue soon repeats itself. Results: As long as I let my car sit and idle, raising the rpm to 2000 to 2500 on occasion, everything works perfectly. But as soon as I shift it into gear and move the car a bit, all of my problems mentioned above surfaces. Can my problem be related to the transmission? This problem puzzles me. Any other thoughts.
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Postby Jon » 06 Sep 2009 3:31

I would look for a short or bad connection. Possibly a faulty fusible link also. :| Movement helps trigger the problem it seems.
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Postby tman » 11 Oct 2009 3:20

Have you checked the Alternator?, or voltage regulator
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Postby fixit » 11 Oct 2009 18:58

check for bad cell in battery
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