Parasitic current drain on 2007 95 Aero auto

[JonD]

I went to start the Saab 95 (2007 model) 3 days ago and the battery was flat, down to about 8V. The ignition key just made some relays flutter.

I am only armed with the Owner's Manual, a Haynes handbook and the web page
http://saabworld.net/showthread.php?t=27821

The battery is only a few months old and is a good quality replacement. I gave it a full charge.

I have been using my multimeter and have found results that baffle me because the drain current seems to be affected by the order in which things are done! I went through these steps

1. Put 10A range on meter and put it in series with the battery
2. Turn on ignition, meter reads 9.02A
3. Turn off ignition, meter reads 4,55A
   after about 20 secs this drops to 2.7A with all doors shut. This I describe as point A.

I then disconnect the battery lead and reconnect it.

1. Meter reads 1.7A for 20 seconds then drops to 0.15A for 10 seconds. Then it drops to 0.10A.

If I pull maxi fuse 2, drain drops to 0.0A. If I replace maxi fuse 2, drain returns to 0.1A. No other maxi fuse, when pulled, alters the current draw.

If I go to the fuse box in the side of the dashboard (fuse box 22a on the side of the dash in the above web link) and pull the fuses, one at a time, it says are connected to Maxi fuse 2 (numbers 17, 1, 16, 20) no fuse causes a change in current.

Turn on ignition etc. and get again to point A, above.
If I just pull fuse 9, current drops to 2.3A, replace it, back to 2.7A
Same with fuse 13, current drops to 1.36A, replace fuse, the CD player makes little robotic noises for about 15 seconds and the current goes back to 2.7A
If I pull Maxi fuse 1, current drops to 1.29A. The current drops from fuses 9 and 13 pretty much match that due to Maxi fuse 1.
If I pull Maxi fuse 2, as described in 4. above, it seems to do a more profound reset that just pulling the fuses that are downstream of it. The other equipment listed in the web reference as being downstream of Maxi fuse 2 are

1. Light switch 10, but I don’t know where that is
2. Main relay 229
3. Starter relay 517
4. Glow plug control module (presumably absent on my petrol vehicle)

I have to consider that these above items may be causing the current draw. My dashboard seems to be different from the one in the web reference and does not seem to have relay box 22b anywhere, so I haven’t yet seen relays 229 or 517.

To summarise, only if I pull and then replace Maxi fuse 2 then I can get the current draw down to 0.1A.

If I go through the sequence to get to point, but with fuse 13 removed, the CD and radio are of course dead, and the current draw is 2.4A.

I should add that I used the CD player a few days before all this, for the first time in a couple of years, so could it be involved in some way?

Well, there it is at the moment. If anyone can offer help I’d be very grateful!!

Kind regards,

Jon D

[GeoffR]

Having owned a few of 9-5s I can tell you that a number of circuits remain live for some time after the ignition key is removed, they are controlled by DICE and TWICE. These units also control the power to the radio/CD player and other systems that shut down after around 20 minutes with the engine off, interior lights for instance. Your 100mA (0.1A) sounds like the load represented by the security system.

I suspect that your ignition switch is sticking, you will have noticed that the barrel moves down (in) when the switch is turned, until the switch returns to the up (out) position there will be additional circuits powered. Normally the key cannot be removed unless the barrel is flush with the surround but wear may mean that this isn't the case. Dirt and debris can get down the side of the lock barrel and limit its movement.

If you decide to lubricate the switch do NOT use oil, WD40 or any other liquid lubricant, you need a dry film lubricant, the others attract and retain debris and will make the situation worse.

May I suggest that you ditch the Haynes "manual" and go here http://saabworld.net/showthread.php?t=33310 where you can download the Saab manuals WIS and EPC both of which will help you to isolate the problem and find the required parts. You will need a computer running Windows XP or later (Preferably 10 for the versions available from the link).

DICE = Dashboard Integrated Central Electronics
TWICE = Theft Warning Integrated Central Electronics
WIS = Workshop Information System
EPC = Electronic Parts Catalogue

[JonD]

Hi Geoff,
Thanks very much for your reply. I think the ignition switch seems OK. When the key is withdrawn the lock barrel pops very firmly and cleanly right to the top of its movement. I will investigate it further though.

I have had a barrel of laughs trying to download the WIS. I did it first with IE11, which, as it often does didn't work (I still use IE11 as I have a massive Favourites folder which more or less locks me in for many purposes) so I moved to with Chrome but when the download completed (25 minutes) Chrome told me that my internet security settings had blocked the download and whatever had been downloaded had then been discarded (how helpful). I made the necessary alteration to the security setting and went to repeat it only to be told by the New Zealand hosting company that my quota had been exceeded and that they wanted me to sign an monthly contract. So I went to another computer and did the download only to find out that this time I'd clicked on the much smaller EPC file. After that had downloaded when I went to do the WIS download I found was then over quota for doing that! At the point of becoming over quota it did at least tell me that in another 4 hours it would resume, so I'm waiting for that to happen.

[GeoffR]

Even if the ignition switch seems OK it is worth checking which, if any, contacts are closed with the key removed.

If you want to move from IE11 you can use Firefox and copy your favourites across. I would imagine other browsers would do something similar.

It is two years since I owned an OG 9-5 so I can't remember where everything is so I am having to rely on a copy of WIS that doesn't seem to want to show me illustrations.
The Light switch 10 is hard to miss, it is on the dashboard on the right.
The relay box 22b is behind the fuse box on the right hand end of the dashboard. You access it from underneath 229 is in the middle column, this isn't the "main" relay it is the engine management relay.
The starter relay 517 is in the same place bottom of the middle column, 229 is two up.
You don't have the Diesel pre-heating relay 641

You might give the relay immediately above 517 a gentle tap, it is the Ignition relay, essentially it is in parallel with the ignition switch. It connects Maxi fuse 2 to the main fuse box, if it is stuck it will cause the problems you are seeing. It can also appear that the ignition switch is the problem, hence my earlier comment. I'd forget about any other relays, pull the Ignition relay and see if the drain stops, if it does check across pins 1 and 2 of the relay, with it removed they should be open circuit, if they aren't that is the problem.

You will have noted that I have changed the names of the relays from those you gave, that is because Haynes have not used the correct names. Mine come from WIS, which is now behaving and showing me diagrams.

[JonD]

Thanks very much for this Geoff. I have tried t act on your suggestions.

I went back and did discover the fuse box under the dashboard - it was much more tucked away than I'd thought as removing the panel only showed its underside and not the tops of the relays. I took out the relay 21 and checked it's operation with a 12V source and a continuity tester - all ok. I tried pulling and replacing all the other relays you mentioned and couldn't get the drain current to change.

I then looked at the ignition switch. While I was getting the barrel out - and before it had come out - the current draw dropped from 2.7A to 0.1A. When I did get it out, it stayed at that for at least 10 minutes. Putting the barrel back in and turning the key to the On position, then turning it off, got me back to the 2.7A draw. I then took out the barrel again and waited. The current draw stayed at 2.7A for several minutes (untimed). I noticed that the metal and plastic piece at the bottom of the barrel's hole - which the key on the end of the barrel fits into - was pushed up by a rather weak spring, weak enough that it didn't quite press it to the top of its motion. I tried wiggling this piece around, and holding it up to the top of its range of movement with forceps, but that didn't induce any immediate lowering of the current draw. When I pulled and replaced Maxi fuse 2 under the bonnet, the current draw went to zero then back to 0.1A, where it stayed. I noted that turning the parking lights on then off caused the immediate drain to be 1.5A and after leaving it for 20 minutes this had dropped to 0.01A. I repeated this, it spent about 20 minutes at 0.1A and then again went to 0.01A.

If there is any uncertainty or likely inconsistency in what I report above, I have to apologise. I think it's maybe because one has to wait appreciable times before one knows whether the current draw one is looking at is stable or about to drop to some lower level. While all the above work has been going on I've been downloading the Saab WIS and getting it running. There is a diagram I've found in there that makes it clear that when turned off, the car is periodically sniffing around electrically, with current drawn from the battery going through complicated patterns of change. This suggests to me that any measuring of current draw while parked need to be interpreted in the light of that activity. Not easy!

I'm beginning to wonder if I have a consistent problem, or whether it's either an intermittent one or what. I think I will leave the car overnight and see what the drain current and battery voltage are in the morning. Advice is still most welcome!

Jon

[GeoffR]

Thanks very much for this Geoff. I have tried t act on your suggestions.

I went back and did discover the fuse box under the dashboard - it was much more tucked away than I'd thought as removing the panel only showed its underside and not the tops of the relays. I took out the relay 21 and checked it's operation with a 12V source and a continuity tester - all ok. I tried pulling and replacing all the other relays you mentioned and couldn't get the drain current to change.

I then looked at the ignition switch. While I was getting the barrel out - and before it had come out - the current draw dropped from 2.7A to 0.1A. When I did get it out, it stayed at that for at least 10 minutes. Putting the barrel back in and turning the key to the On position, then turning it off, got me back to the 2.7A draw. I then took out the barrel again and waited. The current draw stayed at 2.7A for several minutes (untimed). I noticed that the metal and plastic piece at the bottom of the barrel's hole - which the key on the end of the barrel fits into - was pushed up by a rather weak spring, weak enough that it didn't quite press it to the top of its motion. I tried wiggling this piece around, and holding it up to the top of its range of movement with forceps, but that didn't induce any immediate lowering of the current draw. When I pulled and replaced Maxi fuse 2 under the bonnet, the current draw went to zero then back to 0.1A, where it stayed. I noted that turning the parking lights on then off caused the immediate drain to be 1.5A and after leaving it for 20 minutes this had dropped to 0.01A. I repeated this, it spent about 20 minutes at 0.1A and then again went to 0.01A.

Sounds like the ignition switch/lock is at least part of the problem, I'd be inclined to replace it as it clearly has a problem from what you say.

If there is any uncertainty or likely inconsistency in what I report above, I have to apologise. I think it's maybe because one has to wait appreciable times before one knows whether the current draw one is looking at is stable or about to drop to some lower level. While all the above work has been going on I've been downloading the Saab WIS and getting it running. There is a diagram I've found in there that makes it clear that when turned off, the car is periodically sniffing around electrically, with current drawn from the battery going through complicated patterns of change. This suggests to me that any measuring of current draw while parked need to be interpreted in the light of that activity. Not easy!

I'm beginning to wonder if I have a consistent problem, or whether it's either an intermittent one or what. I think I will leave the car overnight and see what the drain current and battery voltage are in the morning. Advice is still most welcome!

Jon

You are over thinking this, good troubleshooting follows a path and replaces/interchanges one item at a time then looks for the effect. You have already seen that something isn't right in relation to the ignition switch so replace it and see what happens. The circuit is simple enough, the switch energises the ignition relay and the relay switches the output from Maxi 2 to the fuse box.

You have demonstrated that removing Maxi 2 cuts the current from 2.4A to 100mA, if it isn't the relay the switch is a high probability.

In my experience the complicated defect is really only a combination of simple things. I can only remember one defect that was more difficult to find than a simple component change and even that turned out to be a single wire that was damaged. Go for the simple first and see if it works.