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ONLY starts on a jump

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Old 01-19-2013 | 11:47 PM
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Matt F.
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From: Central New Jersey-1987 S4 Auto
Default ONLY starts on a jump

Hello All,
Friday night went to take the mistress out of the garage with me to play cards as we usually do when it's not raining. Engine didn't turn over and it felt like a dead battery (replaced old with a new one spring 2012). Lights work, etc., but couldn't get to inspect further (couldn't be late to the game) until tonight so I took my truck.

So, tonight, I hook up the jumper cables and voila...starts right up. Back her out of garage and let her run through and recharge for a few minutes. Turn it off, went to spark her up again and then...............dead again.

....jumped it again to get it back in the garage...started right up...pulled her in and in it she now lies...

So...researching the forums, some things I found sound like my issue.
Bad ground? Alternator died? I have no clue where to start....but want to try to fix this myself.

Any suggestions?
Old 01-20-2013 | 12:33 AM
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76FJ55
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My first thought is a bad connetion. When you were jumping it to start it were you using the jump post up front for connection, or were you connecting at the battery with the cables? Do you have amultimeter to use for diagnosis? First thing I'd do is check the voltage of the battery in the car. test by placing the probes directly on the battery posts, again on the cable clamps at the battery, between the positive battery post and the chassis, and also between the jump post and the chassis. let us know what you get for these values. these will give us a good starting point to assist you.

If it isn't fully charged, the first step would be to get on the charger and get it fully charged. When you know you've got a good battery in it, try again and give us specifics on what it does.

If the alternator is not working the car will still start and run with a good battery untill the battery is drained. if the battery is dead and you jump it to get it running, and if the alternator is not working wit will die when you disconnect the jumpers. So the fact that it continued to run with the cables disconnected but is completely dead once shut off tells me that the alternator is most likely function normally, and you either have a bad battery or a bad connection associated with the battery system.
Old 01-20-2013 | 12:37 AM
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Battery most likely is dead and it won't hold the charge. Also clean the terminals get a new battery and u should be ready to go. If it was the alternator the car wouldn't run once u took off the jumper cables.
Old 01-20-2013 | 12:40 AM
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Default Right way to Jump start

Dude, you jumped it all wrong. THIS is the right way, as posted by another RL member. (Who has 2000 posts so he must be an expert!).

Last edited by 928porschemangreg; 01-18-2014 at 11:50 AM.
Old 01-20-2013 | 12:43 AM
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Now, where's my cigarettes.
Old 01-20-2013 | 12:57 AM
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If you hooked the jumper cable clamps to the car battery terminals, the most likely problem is a poor connection on one of the battery terminals, with an additional possibility that the battery is faulty. The power from the jumper battery would travel over the same positive cables, and over the same ground strap, as the car battery, making it unlikely that a faulty ground strap is the problem.

If you hooked the jumper battery cable clamps to the jump start terminal under the hood and the crossbar fastener, the possible problems also include a faulty ground strap...
Old 01-20-2013 | 12:57 AM
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OK here are a few things you can test before you take anything apart
First open the hood and test the hot post voltage engine off, it SB 12.4 if not bad battery connection or battery charge low

next open the battery cover and test the battery terminals SB 12.4 if not then battery is low on charge, or has failed

get a battery jumper cable and attach it to the negative terminal of the battery and then to one of the shock mount bolts,

NOTE dont mess with the ground connection at the wingnut/chassis ground.or the battery terminal
try to start the car, no start?
If no start then remove the terminals from the battery and apply a 6 amp charger to the battery for 4 to 5 hours,
a trickle charger wont work for this.
While the battery is charging clean the battery terminals and the chassis ground connection, the hot post connection,
and the 14 pin connector above it,
fit a hot post cover if you dont have one.

With the battery charged up test it with the voltmeter .
the car should start,
if it wont then reconnect the jumper cable to the battery ground terminal and the shock bolt see if it starts,
if so then the ground cable has failed internally.

With the engine running check the hot post you should see 13.5 to 14.1 at 1500 RPM ,
if its less than 13.4 then you have a blown diode in the alternator ,
if its battery voltage then either the brushes have failed or the alternator has other issues as its not charging
Old 01-20-2013 | 12:59 AM
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Bad battery, bad battery post connection, bad ground strap, bad ground strap connection to ground point, bad positive cable to starter... all are possible... (I assumed you used the front jump post).

Alan
Old 01-20-2013 | 03:35 AM
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Bad battery. Disconnect it and take it with you to wherever you purchased it along with your receipt from earlier this year, if you still have it. They'll test the battery and exchange it if it won't maintain a proper charge. You most likely have current draws. Current draws kill batteries FAST. You need to fix any current draws ASAP. Your charging system will appreciate you for it.
Old 01-23-2013 | 09:04 PM
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From: Central New Jersey-1987 S4 Auto
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Thank you all for your input. It turned out to be a defective battery which is still under warranty.
Old 01-24-2013 | 01:48 PM
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Routine maint. includes cleaning all grounds and a batt maintainer if the car sits for any length of time; almost all of these have drains. Wally has a great list for the many gounds that can cause various problems.
Old 01-24-2013 | 05:05 PM
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Originally Posted by Matt F.
Back her out of garage and let her run through and recharge for a few minutes. ....
If the battery was dead that is not long enough to charge it, a 20 mile drive w/o lights and radio on, maybe.

Matt you did not say if you have and use a "battery minder/float charger"?

If not, get one, like the others have said you may have a drain and even if you don't these cars are have been known to be battery killers when left to sit for more than a two or three weeks.

Dave




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