Electrical Problems/Battery Dying Out

[Guest deltalady]

Contemplating a Reatta convertible purchase. This one has electrical problems (owner says that battery dies if car is not used for a day or two) and error lights come on to verify this. Owner is looking into problem(s) but they will be mine if I purchase the car. It does have high miles 150K+ (but the price is right). Any advice? <img src="http://forums.aaca.org/images/graemlins/confused.gif" alt="" />

[D-a-n-i-e-l]

probably just a bad batt.

[Guest tomt]

The battery problem may be right on and it is simple to get the battery checked, like before you make the purchase. My Buick Dealer has checked mine in under a minute. My first battery did not die like those I remember from the good old days. It was fine, cranking like crazy till it died while I was having a nice dinner out.

Since then, however, I have had problems since the new battery was installed. My dealer traced the problem to an aftermarket keyless locking system that I had installed after the factory one quit. Disconnecting the system resulted in an immediate improvement in draw. I'd ask if the keyless entry system is factory, and also have a good mechanic/dealer check for draw.

[Guest F14CRAZY]

I would also think that its a bad battery. An auto parts store should be able to check it for free. It's possible that there's a mysterious power draw somewhere, but in most cases, it is just a bad battery

[Guest TommyH]

i had a bad alternator, and the battery would charge enough, so it would die if it wasnt started within a few days. i agree with F14, take it to an auto parts store, like auto zone, or what have you.

[Guest Judster]

Delta, that car needs a thorough troubleshooting session before you lay down your cash. As with all troubleshooting exercises, assume there at least two faults, which may be related or not.

Have your battery load tested. It will tell you whether the battery is near the end of its useful life or is not being charged.

With the same test equipment, check the charging system. If the battery does not show 13 volts or more while the car is idling, it is not being charged by the alternator.

Have someone voltage check your battery while you are starting it. If the voltage across the battery terminals falls below 9 volts while the car is cranking, then your alternator is shot, most likely its internal voltage regulator or rectifier.

Also, have the negative battery terminal disconnected and check the current flow between the cable and the negative battery terminal with the engine and ignition off. Current flow should be less than 2 amps. If it is more than 2 amps you are in for a long and expensive troubleshooting and repair session ($400-$1200).

If you are not interested in doing this yourself, watch and direct the person who is doing it. It will be well worth the 10 or fewer minutes to do so.

[Guest tomt]

He's right there.

Any reputable dealer or owner should be willing to let you have a car checked by the mechanic of your choice. My local mechanic charges $75.00 for exactly this, which he shows as a pre purchase check out. It caused me to pass on my first Reatta for possible motor mount problems. I waited for my current one for a few months, and had the same mechanic perform the same test, which it passed. Worth $50-$75, which it can easily save you.

[padgett]

I have seen a number of problems besides the battery cause this. What needs to be checked is the current from the battery with everything turned off and the doors shut.

Static battery drain for a Reatta should be around 20 ma (milliamps) - this goes for various keep-alives. 200 ma (have seen) and it will be ded in less than a week. For example if the HVAC blower module shorts and the fan stays on, the battery will be drained in a few hours.

Sorry, but to me, a 2 amp static drain would indicate a serious problem, .02 amp (20 ma) is more like it.

Last time checked my 88 was 17 ma. 89-up with RKE will be slightly more. I recall (no garentees) the GM spec as being less than 50 ma.

[Guest Judster]

In this case, less is best without question. I got the parasitic load (static drain) of less than 2 amps for my Olds Aurora. But it has an 880 CCA battery; may be the difference. Do not argue with the 20 ma max limit for my 90 Reatta. Will use this to check parasitic on the 90 next week. Thanx.

Believe my other test/troubleshooting procedures are in order.

Am a retired wrench-wench. Worked mostly on mining heavy equipment. This little stuff is a bit new to me.

Judi