I have a 99 Saab 9.5 wagon with continuing electrical problems. If the car is not driven for 4 or more days , it will not start. So far it has had a new brain, 2 new batteries, new battery cables and lately a new alternator and sparkplugs. The Rear Light Failure message lights up when you turn the key in the ignition, sometimes the car cranks, sometimes it just clicks and will not turn over. Obviously something is draining the system, but the dealer is at a loss to figure out what. Any ideas?
not driven for 4 or more days , it will not start. So far it has had a new brain, 2 new batteries, new battery cables and lately a new alternator and sparkplugs. The Rear Light Failure message lights up when you turn the key in the ignition, sometimes the car cranks, sometimes it just clicks and will not turn over. Obviously something is draining the system, but the dealer is at a loss to figure out what. Any ideas?
The first thing to do is figure out which circuit is causing the drain. Connect an ammeter in servies with the battery (with ingition off). Measure the drain. Start pulling fuses until the drain stops. This tells you which circuit has the fault on it.
Agreed. By the way, watch the fuse in your ammeter, many are 2 amps and if you have enough drain, it'll pop the fuse right away (after which all of your readings are exactly 0).
not driven for 4 or more days , it will not start. So far it has had a new brain, 2 new batteries, new battery cables and lately a new alternator and sparkplugs. The Rear Light Failure message lights up when you turn the key in the ignition, sometimes the car cranks, sometimes it just clicks and will not turn over. Obviously something is draining the system, but the dealer is at a loss to figure out what. Any ideas?
Apart from what others have said, if the rear light warning is on, then you may have a short somewhere in the rear light ciruitry.
not driven for 4 or more days , it will not start. So far it has had a new brain, 2 new batteries, new battery cables and lately a new alternator and sparkplugs. The Rear Light Failure message lights up when you turn the key in the ignition, sometimes the car cranks, sometimes it just clicks and will not turn over. Obviously something is draining the system, but the dealer is at a loss to figure out what. Any ideas?
Assuming that the battery/alternator combination is good, and the battery is being properly charged, I'd say that something is draining the battery.
You might want to check what the normal drain on the battery is with nothing turned on. Some figures I've heard are about 1/2 amp or so.
If the rear light failure comes on, I'd measure the voltage at the rear lights without them on, It should be almost the battery voltage. I'd wonder if there is something odd with the rear light driving circuits, but it's hard to say for now. I don't have access to a schematic, but I'd suspect that something is draining the battery to start with. Obviously, I'd start disconnecting things by pulling fuses with the system in power off, if you have an excessive power drain.
Remember that the battery *should* support leaving the parking lights on over night, and then allow you to start the car normally, and recharge normally. That's based on the UK/European requirement to leave parking lights on a car that is parked on the street.
Not sure what to suggest other than that, for a specific cause.
I relayed your suggestions to the dealer- they have tried the ammeter idea and that didn't diagnose any drain, which make no sense. Any other ideas? Thanks for the help!
that didn't diagnose any drain, which make no sense. Any other ideas? Thanks for the help!
Either you have a drain or you don't - there aren't really any other possibilities. Well, there is another possibility - a faulty battery. But since you say you've replaced the battery, it's unlikely.
If there really is no drain, then the car will start fine after 4 days.
and that didn't diagnose any drain, which make no sense. Any other ideas? Thanks for the help!
The logical deduction, then, is that the drain is not through any of the fuses that they pulled to diagnose the problem. What other fuses are in the car? How many other panels, and what is in it's own panel that they didn't try?
Well - while you did replace the battery - that is no guarantee that the battery was fully charged when you got it or that it wasn't defective in the first place. As it is the only recent 'new' element in the equation - have them load test the battery out of the car as they are digging around for open relays or hot wires that are grounding out in the loom. It may also be that whatever ate your old battery has gotten progressively worst since the new one went in and that is just a bug hunt I'm afraid.
Just for the record - many people make the mistake that you can properly charge a low battery with a long drive when in fact you mostly only put enough of a 'surface' charge on the battery to trip off the charging regulator. Which, would be my next stop after the battery if I were you. Sorry to hear you're having trouble though - it was sounding like bread and roses up until now..
and that didn't diagnose any drain, which make no sense. Any other ideas? Thanks for the help!
There is one possibility, which is an odd one.
Perhaps something is turning on at low temperatures (I think he mentioned that, although if the problem was there in the summer, no joy in finding a solution.
Although bad alternator and/or bad charger connection to battery might be another option.
Thanks for all your ideas, which I will relay to the dealer, who has now had my car for a week.In the past three months he has had it about the same amount of time as us. We told him we were going to put the college stickers on the loaner car, which at least we are lucky to be able to count on. And this is not the first new battery it is the second!!!!!so three batteries in 4 years.
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