1997 Saturn SW2 (HELP)

[Vellyn]

Originally Posted by billr

OK, you say the battery drains "quick", but what does that mean? If fully charged (12.6V or more), does the battery drop to 11.9V in ten minutes? eight hours? What? A good battery, in a good SW2, will hold 12V or better for several weeks. If the battery is going down to 11.9 V just sitting overnight, then disconnect one battery cable and try again, see if the battery itself is bad and self-draining.

Since you say it is the 4th battery, I expect it is OK (unless it has been left discharge) for hours at a time). So, I am focused on parasitic current draw, but we need to have confidence the battery is OK. I suggest you take it to a FLAPS for load test, too.

Whatever further testing you do, be sure to always start the drive/test with the battery fully charged! Not only will this keep the battery healthy, but it gives us somewhat of a stable base-line while evaluating the symptoms you then report.

Did you try disconnecting the 10-wire cable on top of the trans and taking it for a ride? With that cable off, all electrical influence on the trans is removed and the engine should not rev freely without the car trying to move. The engine will rev up to about 2500 rpm if you give it full throttle; that is the stall speed of the trans torque converter. And, the car will not accelerate fast, even at full throttle, with that cable off. But the car should certainly not feel like it is going "backwards". If the engine rpm goes much past 2500 rpm, then there is probably a problem inside the trans. Tell us what you get.

The battery is draining within half an hour to an hour from 12.5v to between 11.9 and 11v. The battery when disconnected stays at around 12v.

We don't have a FLAPS but we have an Autozone. We had the alternator tested but haven't done a load test.

We have not tried the trans cable. (we should note, sometimes when shifting (typically into reverse) the car shifts hard and makes an audible thud)

[billr]

"The battery when disconnected stays at around 12v."

That is exactly the kind of testing/reporting I am trying to wean us away from.

Do you mean the battery cannot be fully charged into the 12.6-13.5V range? (bad battery)

OR, do you mean it fully charges, but drops down to 12V in less than a couple of months when disconnected? (also a bad battery)

OR, do you mean you haven't fully charged the battery, it will remain right as it was (12V) for a long time when disconnected? (a far less useful/definitive test)

Clarify what you did, and repeat if the battery was not fully charged.

Next, get the battery load-tested, I don't care about the alternator right now. FLAPS is simply our abbreviation for "Friendly Local Auto Parts Store". Autozone is what we would call a "FLAPS".

The trans hard shifting could be related to the electrical problems, or it may be a problem with the trans alone (the VB, Valve Body, is a frequent cause). With the 10-wire cable disconnected the shifting will be harsh, and you will only get R and one forward gear (3rd or 4th); I just want to see if the engine easily revs past 2500 rpm that way.

I am trying to lead you in a logical trouble-shooting order here:

1) Determine if there is an abnormal parasitic current.

2) Determine if the battery is OK. That can't be done reliably on the car unless we know, for sure, that there is no abnormal parasitic current. Load testing is also needed, and that is easiest done at the FLAPS. But the FLAPS testing is not 100% reliable, so don't be surprised if the battery passes that and I still ask for you to try an on-the-car DIY load test.

3) Once the battery is known to be OK and we are sure there is no parasitic, only then can we definitively test the alternator. Yes, alternator output can be tested right now, but the results could get confused if the battery or parasitic current are a problem.

4) Finally, once the battery and alternator are known good, and keeping system voltage in the 13.5-15V range while the engine is running, we can properly evaluated the trans issues. This type trans is sensitive to system voltage, so once other electrical issues are resolved the trans may be "self healed"; but I doubt it. The trans has some very common VB problems