Electrical Gremlin - Help Please

[lyme]

Hello,

I've searched and tried everything already posted for this problem. I've been to every technical saab site on the net and checked all the news groups. It seems everyone who's posted anything similar has been a first poster. It seems everyone who's had these problems has somehow fixed it but I can't find a conclusive post as to what has fixed it.

The was long winded. Sorry bout that. Here is my problem in its truest form. For some reason I'm losing charge from the alternator spiratically. I can turn the car on [with the lights off] and it will charge itself fine. In park I can turn the lights on and it will charge. I can run every electrical feature while in park and it will charge. I then drive the car roughly ten minutes and it stops charging. When this happens the radio goes off. It "seems" this all occurs when I either am moving the gas peddle to the floor or am braking. You could call this the "trigger". I have NOT had any of this happen with the lights off.

Now for the things I've done. I've had 2 different alternators in the car. I've replaced the thick ground wire from the alternator to the engine block. There is a "red" wire that runs from the alternator to "something". [I have not spent enough time investigating what the heck that is. Anyways there is a yellow wire above the red one and I've replaced this. I've disconnected the cooling fan and run the car. I've pulled the cooling fan fuse and ran it. I've checked "only" the wires in the igintion switch and NOT the switch itself. I've swapped batteries. I've taken the radio out and replaced it. [Don't ask] I've taken the light switch completely out and it HAS done this. I've taken ALL of the switches out in the dash and it HAS done it. I've taken the WHOLE instrument out and it HAS done it. I've unplugged the heated seats and power window switches. I have taken the light switch apart and noticed a number of ark points and material left from the little contacts on the tabs. I cleaned those off and replaced it. Same thing every time.

Now since this only happens when it drives I have a hard time running a meter to test these things. Now I need a favour or explanation or the charging circuit. If someone could scan the schematic I'd appreciate it. I thought I had it fixed but now its back and I have a trip in 2 days. It may be wishful thinking to hope that I can fix it 2 days but here I am. I've checked everywhere locally for a book but to no avail. Any online order isn't going to be shipped now until Monday and thats when I leave. All in all this sucks and I appreciate any and all the insight you would have on this prolem.

Thanks in advance!

Charlie

[Willy Wonka]

Wow you've done a lot of testing. So here goes a quick first response. Try one more, a wire directly from the output of the alternator, usually red, to the battery. Connect this after the car has started and disconnect prior to turning off. Use 10 gage wire or thicker. It it works then follow the wire from the battery to the little funny connecter box on the rt frt fender to the light relay and alternator.
Btw also check that the engine gnd is clean as well as the front cross brace gnd.

Better yet use jumper cables from the battery + and - to the alternator + and -. Secure and drive.
Btw if it still does it check the gear selector first.

[REDTURBO84]

Hi, You could take it in to Autozone or Advanced autoparts for a free, electrical charging system check.They will load test it to see which componet is faulty .They saved me on wifes car.I thought it was the alt. Turned out to be a shorting battery.System was fine.Pat

[Knuser]

What year is your 900? I may have the schematics for it.

[lyme]

Originally Posted by Knuser

What year is your 900? I may have the schematics for it.

Woot! 1985 900 16V Turbo.

I'll try the wire in the morning and if I can get it to go run it to autozone. Actually in dane co wisconsin I don't think there is an autozone. Just checker. I realy despise CSK Auto.

Thanks for your help everyone!

Charlie

[lyme]

Originally Posted by Willy Wonka

Wow you've done a lot of testing. So here goes a quick first response. Try one more, a wire directly from the output of the alternator, usually red, to the battery. Connect this after the car has started and disconnect prior to turning off. Use 10 gage wire or thicker. It it works then follow the wire from the battery to the little funny connecter box on the rt frt fender to the light relay and alternator.
Btw also check that the engine gnd is clean as well as the front cross brace gnd.

Better yet use jumper cables from the battery + and - to the alternator + and -. Secure and drive.
BTW if it still does it check the gear selector first.

What do you mean gear selector? [I know what a gear selector is just what from there would cause the problem?] How would I check that?

The red wire from the alternator goes to this funny thing, I haven't investigated, where I replaced this yellow wire. What is this mistery thing? I assume the voltage regulator is built into the alternator. So what is it?

[eggsngrits]

I think that these schematics may help....

http://saabpics.org:3000/gallery/album176

Mike

[Knuser]

The -85 and -86 schematics are quite simple. I have just PM'ed you a copy as I do not know how to put it here.
The connections are:
Battery +
cable colour: RD
Starter motor pin 30
RD
Alternator pin 8+ (Check if the alternator earth is good!)
Alternator pin 0+
GN/VT
29 pin bulkhead connector 152C behind main fuse panel
GN/VT
charging lamp with diode in instrument cluster
BL
29 pin bulkhead connector 152B behind main fuse panel
GN/VT
+15 distribution in main fuse/relay panel
GN/VT
Fuse 22
+15 GN/VT

Good luck!

[lyme]

Thanks! Although I have not received anything in my mailbox.

I'd still like to know what the thing was with the gearbox that I'm supposed to look at.

Morning!

Charlie

[lyme]

Or maybe just too much whiskey last night in the swell of this problem.

I've been pouring over these schematics...being a toolmaker and now a design engineer [mechanical] its tedious for me to figure this out. Being its electrical.

Anyways. The trigger I talked about before was the braking or accelerating. Thinking about it would seem its more braking that may be the trigger. I notice ground [earth] 9 in the schematics. This is located near the spare tire in the trunk. If this were lose or faulty and I hit the brake would it cause the whole system to fault hence the battery being drained? NOTE: The APC is grounded by this ground as well.

Additionally can anyone give me a brighter clue as to where ground [earth] 3 is behind the dash?

Charlie

[lyme]

OK. So 3 or so hours this morning pouring over scematics and then heading outside to tinker with the Saab. I had planned to work on my beloved MR2 this weekend but the Saab is my daily driver.

First I have to thank everyone who posted and especially for the link to the schematics! Looking them over is when I realized that one of the culprits may have been ground [earth] marked 9. So the first thing I did was pull all my tools out of trunk. Lift the little latch up and to my surprise there was a pool of water in there. It seems some dirt and muck had plugged the drain pluggs. I didn't pay much attaention to the water until I started tracing wires. I notices a green and a red wire hanging and the ends drapped near the start of the deeper pit of the cavity. I pulled the spare out and found the end. Still damp from the previous night and full of muck. I have absolutely no clue where the male connector this green and red wire are supposed to go to.. hmmm Anyways I snipped the end [not really very appropriate but I can always run new wires as I have through most this car already] and tapped up the ends. Zip tied them to the cross member and took it for a 30 minute test ride. Ending the ride through many quick stops and accelerations. The gremlin did not show its filthy face once.

So, I think this may have been my problem. Braking and accelerating causing the water spash around back there and cause current to travel through the pool and ground out.

This is by far the most obscure problem I've had with a car.

Again I truly appreciate everyone's help!

Charlie

[REDTURBO84]

Hi, I fixed my constantly leaking hatch with a 3/8 drill bit and 1" piece's of hose and clear silicone. The old 84's compartment is dry even during the worst downpours :wink: The side vent windows are the place mine gets in the spare tire well. Pat

[lyme]

So what I thought had fixed this god forsaken problem did not. Now its back and I'm totlally confused. Like I wasn't before.

After the car started do the same things as it did before I decided to pull apart the iginition relay. It had arc points on the contacts. Running an ohm meter across poles 3 and 4 while engaged showed some resistance. Not a good contact. Now I drove the car on a fresh battery so we'll see after a couple hours.

A couple thing I noticed today though that have me curious. The gas gauge flucuates.... Is this normal? Also with the car off, in park and ignition to the on position I applied the brakes. The four idiot lights dimmed a bit upon application of the brakes..... Is this normal?

If the relay does not work I'm out to rewire ground [earth] 7...what fun!

Thanks again!

charlie

[john-w]

This sounds like a ground/earth problem, if you have some jumper leads, put one end on the battery earth and the other to the engine, see if this alters anything, or from the battery to the body.

[lyme]

soory if I keep posting to my own threads but this all may help someone someday. Who knows.

So I investigated ground [earth] 7. Someone had connected 5 different ground plugs to the cross member with a wood/sheet metal screw. I'm blown away. I didn't look at it too much sine that other connector was drapped into that pool of water. I've made new connections and two separate ground posts. Using a separate nut for each ground wire.

Low and behold the gas gauge didn't flucuate. Hope THIS will solve my problem.

I noticed now when pressing on the brakes and having the car running that the turbo needle went up a touch with the Tach. You could hear the engine go just a little bit faster. Is this because the car is calling for more current? [since I drained the battery a bunch on my way to work] Who knows.

I'll update in the next coming couple of days....and if this doesn't work I'll try the ground wire to the engine and chassis like your suggestion. Thanks!

Charlie

[lyme]

Yet another add to my string of posts.

It did it again! Sound ground [earth] 7 is fine. Time to try all the wires mentioned above. I'm still curious about the wire on the tranny. Would that cause this?

This has been my first drive in the night with this car in a very long time. I noticed something new now. When accelerating and hiting 3,000 RPM the battery light starts to come on. Slightly and then gradually increasing to full brightness at 4,200 RPM. Then the car upshifts and the light comes off. This is a repeatable phenominon. [spelling]

Does anyone know what causes this? Has anyone had this battery light problem and found the problem?

This is soo frustrating.

Charlie

[lyme]

Today I've taken off the main positive and negative cables, checked for continuity and cleaned the connections.

Still the same problem. The battery won't charge.

Another thing noticed in the dark tonight was when I turn the car off the battery light and the light next to it go on. If this means anything. This is on top of the gradual brightness when going from 3000 to 42000 rpm.[listed in a previous post] I also noticed the battery light does NOT go on when the car has just been started and it is in park.

Hmph!

I'm at either the ignition switch or something in the distrubution terminal.

The ignition switch functions as it should. Turning the car to parked, on and start. If its faulty, would it cause the battery light to come on like that when turning the car off? would the ignition switch be bad and still function like it would normally?

What items has anyone seen go bad in the distrubution terminal to cause the battery to fail?

I suppose tomorrow will be a day to take the whole distribution terminal apart. Anyone have an hints for getting it apart easily?

Thanks

Charlie

[Heiliger]

Well.. Im completely stumped man... Ive been following this thread for days... I think Im about as frustrated as you are. Anyone have some help for this guy?

I hope you get it worked out man... sorry I couldnt be of some help.

Dont give up!

[Willy Wonka]

I'm not convinced that the alternator is ok. Prove it. Remove all the wires to it and test them use a continuity meter. Then replace and start and run and test the voltage levels. They should rise till they stabilize 13.5 +-.25 . Wait the ten minutes and note what's happening. If the voltage starts to drop. Gently tap the alternator on the casing on the side nearest the radiator. Gently, you're trying to check for brush contact. Nope. Start removing fuses one at a time, noting changes in voltage. Make a table. This is the easy stuff. Prior to really testing the wiring take the car to auto zone they have a load tester for the alternator. If the alternator is good under load. Then we should be smelling burnt wires. If that's the case then you've found the short. If not then it's a voltage regulator issue. Test the indicator light for operation and type. Some alternators/regulators use the light as part of a bridge circuit.
BTW there are 18,000 champaign producers in France. Think you've troubles, try putting on a blue coat and sorting them.

Ok back to the electric. Take the sensor wire to the regulator to positive through a 30k variable resistor. Slowly increase the resistance. I haven't had to do this in since I was 14. The output of the alternator should all of the sudden start to change near it's bridge resistance value.
Did you say, you had changed the alternator as a test?
Ok if it changes then look to the indicator circuit. If not then try another alternator or get it tested out of the car by an electric shop.
Do you have an alarm? There's a device called a time delay relay which is a counter now, but used to be a heat driven device, that could cause this issue. After you've solved this we'll get into how to selectively mimic this with the time delay relay.

[lyme]

Thats actually a good suggestion. Although now I think I may be an idiot.

I have checked to see if the battery was getting a charge when in park but not under high load. ie. 3000-4200 rpm. Could it be possible the belt is slipping on the crank shaft pulley? Hence the light coming on under high load and getting brighter the faster you go. I know that belt tension is good but I don't know that the crank shaft pulley is clean of debris or oil.

I'm seriously going to kick myself if thats it.

I'm going to look into the belt today and test the alternator like you suggested. Note: Yes, I had a new alterntor on the engine and the car did the same thing. My assumption was that it could not have been two different alternators but as murphy has his was his with me I may be wrong.

Thanks!

Charlie