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Discussion Starter #1
1986 900 8V NA I wanted to start a fresh thread on my electrical problem.
Here's what I've done to it the last 2 weeks or so:
-alternator taken out and checked at autozone = good
-new voltage regulator
-new postive battery cable and cable to frame
-new negative battery cable and cable to frame
-new cable from alt to starter
-new ground wire from alt to engine block (2 in fact)
-new battery
-battery and charge bulbs (dash) are good, light up, etc.
-all grounds that I can find have been inspected, cleaned, and fixed if needed
-wiring and plugs going to back of instrument cluster inspected, appear good, no visual problems at all
-new hall sensor in distributor
-new hall sensor plug/harness going to distributor
-misc. this-n-that
Symptoms:
With my old battery, it would start with a jump, run good for a bit, then when lights or anything electrical was turned on, sputtering, stalling, dim lights, wipers not working, etc. like it's trying to run off the dead battery.

Was told there's possibly a short in the old battery, so I got a new one..a good one. Drove most excellent for one day, and I was sure I had solved the problem, then suddenly the next morning it started sputtering again, lights dim, wipers and everything would hardly move at all...limped it home with barely any headlights, now the brand new battery is dead as hell!
Not only did it NOT charge the battery but it drained it dead as it can get in about 1 mile. I can still start it, with a jump, and it'll run fine, lights and everything electrical on, for a short period of time then starts to die. If I turn everything off it'll run...crappy, but runs. Turn the engine off, try to re-start, new battery completely dead.
It's obviously not charging but I can't find anything wrong...and there's not much to the charging system anyway. Could the ignition switch be causing it? Could a ground going to the plug for one of the headlights cause such problems?
Have I missed something? What else is there to check?
cheers-
 

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I had the exact same problem in my Volvo, unforunately I had no idea how to fix it. I would go over and check and clean all the grounds. My friend's father had a Ferrari that would kill the battery every night, and would start with a jump but wasn't really good to drive, so based on what he found in the Ferrari, it could be something is staying on, like a light or something or if you have an alarm system in the car that could be drawing power as well. Just my 2 cents, I'm not too familiar with electrical systems but thats what I'm thinking.
 

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1. Does the battery light on the dash work? It should come on for a few seconds when you first turn the key on.

2. Is the alternator grounded, there should be a wire going from the alternator frame to body or engine?

It appears you are not charging so your running off the battery which will support life for only so long, and when you turn accesories on it puts too much strain on the battery and you die.

-alternator taken out and checked at autozone = good
You can't trust that, I've had them diagnose bad ones good and good ones bad. Do you have a spare you can check it with or at least take that one out and have it checked again, maybe at a couple places. :p


And run a wire from the alternator case to the fender to help ground it.
 

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Discussion Starter #4
thanks guys -
I've got the alternator grounded at the engine/alt bracket and also at the bracket that holds the throttle cable (per my Saab mechanic friend's suggestion) both are new cables.
The alternator was such a pain to remove and reinstall, I'd hate to do that again without knowing positively that it's bad. I made the guy at autozone run the test twice, in front of me. I guess I could go pull a salvage one this friday, and swap them out and give it a try. I'm planning on spending a little time this afternoon cleaning some more grounds, etc. and just basically double checking everything (that I've looked at 10000 times HAH!)
If and when I find it, I'll post back...hopefully it'll help the next guy who has this problem, and wants to torch his Saab - like I do right now!:cheesy:
 

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Discussion Starter #5
Hold the phone...

I might have figured it out.
The alternator stops and the battery tries to run things ONLY the car starts to warm up. Could it be the alternator crapping when it heats up?
This would explain why when I took it to Autozone, it checked out fine...it had not had time to warm up yet!
And when I start it, it'll run perfect until it begins to warm up a little bit. Like, the alternator starts to get hot, and stops working...causing the battery to try to run everything.
Make any sense?
I think I'll pick up a spare alternator on friday, and give it a try. Can't hurt anything except my wallet HA!
thanks all, I'll keep you posted!
:D
 

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Simple test to find out of the altenator is working.

Turn your cabin heaters on and rev the engine, if the speed of the heater fan picks up your alternator is working, same with the head lights.

I would have said make double sure the alternator is charging and make sure the D+ on the altenrator has continuity or how ever you spell it:lol:.
 

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You may very well be on to something with the heat and lack of charging. I haven't had that particular problem, yet, with a blower motor on a suburban, I saw the very same thing happen. It was blowing to beat the band while the air it was pushing was cool. As engine got hotter, the heater core got hot, the silly thing would start slowing down. After 1/2 day of cussing and bleeding, I got the motor out and heater core. The blower motor ground wire had 3 or 4 strands of wire making contact. The other 20 or so strands were broken.

Check that alternator while she is hot if possible. It is a pain, but knowing that heat makes wires move and do funny things, you may solved your mystery.
 

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As heat rises resistance increases.
Perhaps you have a failing breaing in the alternator that is causing heat due to friction. The other thing to look for is the exciter wire. It hooks onto the alternator near thee top on the little spade lug. It's a flimsy connector on what I think is a way too tiny wire. I know ya don't need much current, but it could be a bit beefier.
Good luck with that.
 

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Discussion Starter #9
OK today I put the new alternator in, got everything buttoned up, started it and while it was cold it ran perfect...all lights, wipers, EVERYTHING on.

As soon as 'something' in the car got warm, the SOB started doing the SAME F-ING MOTHER-FING THING!!!!!!!!!!!!!AAAAAAaaaaaaaaaaaaaaaajHHHHHHh

I'm so angry at this car. I've looked at every ground, every wire, and almost everything is new that has to do with the start and charging system!

I know it's got to be a temperature thing...when the car is cold it's perfect. When it gets warm it starts running off the battery so it kills it.
I'm not sure what to check now so I'm having a martini and letting the battery charge. The martini is stirred...not shaken.
 

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...shaking the martini might help expel some of the negative energy you're getting :D

More seriously though, get a muli-meter hooked up to measure the amp. output of your alternator. It may not be charging when the system is "cold" either, but just running off the battery till a certain point...

Heat also increases the resistance of wiring: try removing all the fuses and relays to systems that don't need to be online to start/run the engine. If this eliminates your "warm-up" charging problem then start reinstalling the fuses/relays one at time while monitoring the charging system.

You mentioned getting an alternator from the junkyard--are you 110% SURE the "new" alternator is working properly?

HTH
 

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I cant believe your having so much trouble:( this is terrible after everything you have done so far.

I dont understand why ultimately your alternator is not producing current after it warms up, but this is the key right there, some how when things warm up your alternator is not working correctly so i think the wiring for the dash is in question.

It could be your ECU but am not sure, maybe you should prey;)
 

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Discussion Starter #12
thanks banman and shadowWorks...I can't believe I'm having this much trouble either!
When I try to start it, the battery is dead. Completely dead. I can jump start it, then it'll run like a champ, wipers and lights on...if I let it run for a few minutes BEFORE it warms up, the battery is fine and I can shut the car off and start it again! So that tells me it's starting to charge the battery.
It has to be cold though. If I let it run until the car warms up, it does the 'wants to run off the battery' thing, and when I shut it down the battery is dead as hell. Then, if the car is warm and I jump it, it's still the same...trying to run off the battery and not only that, but draining the battery dead.
I'm 100% sure that alternator is good. It's a rebuilt that came from my trusted Saab repair shop. I even took out and inspected the VR before putting it in the car. The old alternator had a new VR in it too.
The only things I can think of, and I might be off base, are:
Starter? Could there be a problem with it and it's shorting out internally or something? The car starts fine (when jumped) the starter has no indication of being bad, but it's in the line with the wiring.
ShadowWorks you mentioned the dash...I read on a thread here, after searching (I've probably read 100 threads researching this problem), that someone had a charging problem, and after all the crap they tried it ended up being the 'trigger' wire going to the back of the instrument cluster. Now, I pulled the connections from the back of the instrument cluster, both of them and inspected them. All wires and connections look good as new. I couldn't find anything to even TRY to fix. I'm wondering if it could be inside my instrument cluster...but all of my 'idiot' lights work. The charge and battery lights BOTH come on when the key is turned, like normal.
I'm stumped, not sure what to do next except buy a Japanese car again!
ANOTHER MARTINI PLEASE SIR!:evil:
 

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Discussion Starter #13
and Shadow you also mentioned the ECU. Is it the black box in the driver(US) side wheel well near the small relay box? It seems to stay cool though, unless I'm wrong and it's a time 'thing' instead of a 'temperature' thing...like after a certain amount of time, it dies.
It doesn't seem like the ECU gets very warm, but I suppose it would be getting warm 'enough' and turning off the charging system? Am I making any sense at this point?:D
I appreciate you guys' help!
 

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this may be totally off - but i had a similar situation (not exactly the same but similar) and its worth a try IF you have electric belts. The electric seat belts were sucking the living hell out of my battery - so far dead that it would not hold a charge (new battery). the cure was taking out their fuses (under rear seat) just a thought if you do have electric seat belts. i think there was actually a short inside one of the motors (i don't mind putting them on by hand) so today i sit with no electric belts.
 

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Ok i know whats going on, you have a current drain in your system even when the ignition is off.

There is a way to find the problem, first get a multimeter with the ability to measure current, at least 10 amps, disconnect the positive terminal on the battery, you then place the multimeter in series with the battery terminal to the positive battery cable and i would bet my last dollar you have something sucking power from your battery when the ignition is off.

!PLEASE DO NOT ATTEMPT TO START YOUR ENGINE WITH THE MUILTIMETER CONNECTED!
It is only designed to carry low levels of current from small systems, no more than 120 watts

It is normal to have say 250milliamps of current draw from the clock and alarm say but anything over 0.5 amps is a problem.

The way to locate the problem is by pulling out fuses and doing the same thing with the muilimeter, positive probe on one fuse holder end and negative probe on the other fuse holder and when you find the current drain which does not belong too the clock or alarm you have hit the bulls eye;)

I cant guess what system or item has gone bad and is drawing current but this is a sure fire way to locate it, just take your time, also look out for aftermarket installed radios which may be doggy.

There is one other thing i can think of but get back to me first after you have done this first.

Your trouble is coming to a head I am sure, the most important part is to not worry or stress about it.
 

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Part 1

To narrow this down.................

you may need to aquire some additional tools to measure some basics.

Definately a Voltmeter/multimeter. A must to be able get some indication of voltage changes. Doesn't have to be a very expensive meter, just something that will show voltages easily.
To go the extra step, a high current tong to measure current flow around the alternator.
When taking some measurements, one needs to keep the same loads or conditions while hot and cold or perfom the same tests while hot and cold.
Generally, I believe the only major change one should observe is the reduction in current draw to the battery while the battery recovers from start up, and the voltage reduce as the alternator gets hotter, ie receed back from the 14.0 volt limit to about 13.8, 13.5 volts.
Some Pics.........
Tong and meter to read tong output.


Tong in place to measure alternator positve current flow.


Meter reading just after start up....lights on, A/C on MAX, revs @ 1500rpm.


after 2 minutes...
 

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Part 2

Tong in place measure CAR current load,...


and reading....


NO load, just car running, no lights or A/C.



Current flow from the alternator will vary relative to battery condition and car load. The voltage variation may be in the order of 1 to 2 volts depending on load and battery condition and temperature of the alternator but should not be allowing the voltage to go above 14.0 volts.
 

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Part 3

As I mentioned in the earlier post, have you managed to establish if the wires for the oil press. and alt bleed are in the correct positions?
Measure the voltage on the alt bleed wire when it's cold and when it is hot, ( should remain the same voltage, HOT or COLD) squeeze the recepticle plug with pliers to make the grip tighter. When these recepticle plugs age and get hot, they can lose their temper and the metal/copper in the plug can become weak.




Has the globe for the batt lamp been changed at all?
If so, is it the correct WATTAGE? The resistive property of the batt globe is important, it's not about brightness, it's more to do with current bleed across the excitors in the alt.

To see the list of items you have changed certainly covers just about everything, you're almost there!

Good luck.

(An hour later..... then Too many pictures:evil: )

Post edit,......6 hours later.....
What is the CCA rating of the new battery? Brand?
My money is on the alt not charging for some reason.
The first and most indicative check, measure the voltage after start up and turn on your lights and blower fan, rev to above 1500 rpms. Should be 13.2/13.5 volts steady.
If it's near 12 or below, the alt is not charging.

Let's assume for a moment that the alt and battery are O.K.
To have the battery die that quickly, to would be safe to assume that the load required to drain the battery would need to be in EXCESS of 100 to 150 amps (CONSTANT). That is, the 80 amps that the alternator would be supplying plus current being drained from the battery as well. If for arguements sake that this load is at say, at best, 100 amps, power dissipated would be around 1200 watts. One would be able to smell or feel or see cable insulation just melt before your eyes if such a constant load was evident. That's equal to a half size electric bar heater. There would be very few items in the average car that could use that much power on its own.
When you described the cars' behaviour when you installed the fresh new battery, that for me did sound like the alternator was or is not right. I would've expected to see the car run for at least a day (with few items switched on) on a good battery if the alt was inactive.
Are you able to give the new battery an overnight charge on a trickle charger? I would believe the car will run like the day you bought the new battery if the battery has a long steady gentle charge.
 

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Discussion Starter #19
Man, I can't thank you guys enough...especially Rodentmaster, for all of you help! I've got the battery on the charger (been there all night) and will get the meters I need...soon as I can wake up this morning and hit the store.
To answer a couple of questions: Yes the charge and battery lamps in the dash light up, and goe off once the car is started. They haven't been changed since I've had the car, which has been a while, and this problem just recently popped up. I'll change them out today, just to be sure. Also, I'm positive the oil light and the alt bleed are plugged in properly. Today I'll pull the alt cable and strip the nice black outside covering away and see if it's stripped somewhere along the path. All other cables are new!
Yesterday while changing out alternators, I checked that plug and squeezed it a little to make sure it was tight. I dropped the plastic cover down into the great void of Saab wheel well, and I guess I'll dig it out today. It was getting late and I gave up.
I'll post back if anything happens (or doesn't happen ) later today!
Again - many thanks!
:cheesy:
 

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Discussion Starter #20
OK, I took my full charged NEW battery (sat on the charger all night) out this morning and hooked it up. The car started right up, ran like a champ, warmed up and is acting like normal. This is what it did when I got the new battery so I thought it was fixed.
So this morning I let it run until it was warm, shut it off and started it back up about 10 times. Both the battery light and the one next to it, charge I'm assuming, come on like normal. The battery lamp is a 2.0 (green case) and the charge is a 1.2 (black case) Actually all of the bulbs in the dash are 1.2 except the battery bulb. Are these lamps they sell at Autozone or Advance Auto Parts? I can order them online I suppose.
I'm wondering if that 1.2 charge bulb is causing the problems. It comes on, but I've had the car a couple of years and have never changed any of the dash bulbs, so who knows how old it is. I would think if it were preventing the alternator from charging, it would have to be OUT. Don't know.
Anyway I'll get a meter when the wife gets home and do some more troubleshooting. Thanks again all!
HAPPY NEW YEAR!
 
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