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Discussion Starter · #1 ·
So I finally got the clutch and clutch line put together, and in the process I knocked off a black, ~16 gauge wire that appears to ground at the intake manifold (just behind the throttle).

At the time the wire appeared to go to the alternator negative, so I bolted it on there. But afterwards, the engine was acting very erratically, and some electronics like the radio were acting strange.

I've scoured the wiring diagrams and no components list having a ground at the intake manifold, at least that I saw.

It's an '89 Turbo Conv. Can anyone tell me where this ground connects to?
 

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Some people run extra ground wires to the intake manifold for the alternator, b/c the factory ground wire is a POS and causes problems. Since these cars are so old and been screwed with by how many people you would need to take a picture that way we can help further.
 

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It grounds at the intake manifold. 1 in 100 cars have problems without it. Nobody knows why. I asked SAAB Service instructors, SAAB engineers, and SAAB district service reps. Maybe someone in Sweden knows.
My best guess is a 'dirty' stray AC pulse from the alternator.
 

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Discussion Starter · #4 ·
See, it's no doubt that it grounds at the intake manifold. It's the other end that got knocked off.

Just as a test, I ran the engine with the wire on the alternator. The check battery light was on and after revs it would take forever to get back to idle. Then I disconnected the wire and the idle was much smoother, although the car was a little harder to start.
 

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Discussion Starter · #5 · (Edited)
So, since it goes to the alternator, which connection does it go to? There seems to be a ground point with a little connector on it and another one at the bottom that has a fat black wire coming from it.

The engine seriously runs terribly whenever I have route this wire to the ground point with the connector on it. Plus there's a persistent battery warning light as well.
 

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It goes to the body. Under a retaining clip maybe? I haven't seen one in a long, long time. Make sure your alternator ground wire (alternator case to engine) is intact also.
 

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Discussion Starter · #7 ·
Sorry, I'm just a little confused... so this wire connects from the intake manifold to the car body?
 

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There should be a heavy gauge wire from the alternator to the block. The lighter gauge wire goes from a bracket on the manifold to (I think) a small hydraulic line retaining clip on the inner fender.
Alternator grounded to block, intake manifold grounded to the body nearby.
 

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It's a stupid little 10 or 12g wire that runs from intake manifold (or oil tube) to the inner fender sheet metal.

I have one on my 92. Makes no sense at all; absolutely mandatory if you have one or the car runs like poo.
 

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So, since it goes to the alternator, which connection does it go to? There seems to be a ground point with a little connector on it and another one at the bottom that has a fat black wire coming from it.

The engine seriously runs terribly whenever I have route this wire to the ground point with the connector on it. Plus there's a persistent battery warning light as well.
This makes me think you grounded the warning light connection on the alternator. This would give you a "charge light" that will not shut off and would prevent the alternator from "self exiiteing" so rough running is likely caused by low battery voltage.
There were a few different alt configutation used, but the ones I'm familure with do NOT have a quick connect for the ground wire, which must be connected to the case (most often a thru bolt is used for this).
 

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This makes me think you grounded the warning light connection on the alternator. This would give you a "charge light" that will not shut off and would prevent the alternator from "self exiiteing" so rough running is likely caused by low battery voltage.
There were a few different alt configutation used, but the ones I'm familure with do NOT have a quick connect for the ground wire, which must be connected to the case (most often a thru bolt is used for this).
I would agree. The alternator earth should be a thick gauge wire. The warning lamp/exciter terminal sits above the alternator earth and will have a small stud which should either accept a small ring terminal or spade terminal.
 

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Agreed...but that's not what the o.p. is talking about. Like Jim said some of these US jobbies have a thin gauge wire that runs from the manifold to the inner fender sheet metal and the car will absolutely not run properly without it if it has one there to begin with. Mine has one and I can assure you it will absolutely not run correctly if it's detached.
 

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Agreed...but that's not what the o.p. is talking about. Like Jim said some of these US jobbies have a thin gauge wire that runs from the manifold to the inner fender sheet metal and the car will absolutely not run properly without it if it has one there to begin with. Mine has one and I can assure you it will absolutely not run correctly if it's detached.
No, I understand the O/P and I know the thin wire you are talking about... I just was saying where he attached to the alternator was incorrect and caused some of the problem. There are two seperate problems, where he did atttach it, and where it should be attached.
 

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Agreed...but that's not what the o.p. is talking about. Like Jim said some of these US jobbies have a thin gauge wire that runs from the manifold to the inner fender sheet metal and the car will absolutely not run properly without it if it has one there to begin with. Mine has one and I can assure you it will absolutely not run correctly if it's detached.
Interesting. Never seen this extra earth wire on a c900 intake before.
 

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I ran one from that accelerator bracket to the side fender where the ignition ground bolt is.
Eliminated some jerky response when on-off-on throttle in traffic.
Other ground wire I added was a second wire from the AMM connector to the same accelerator bracket. I did this chasing the consistent idle error code in the ECU. 12112(?) now only occurs occasionally, maybe after weeks, where as before it was within 30 minutes of a ECU reboot.
A hot weather quirk that also seems to have been eliminated is the car driving, used to develop a heavy low frequency surge in ambient temps above 35 deg C.
I've been braving the trips to work in the recent run of 35 to 40 C degree days here and the car has been great.
Don't know why this has worked.........
I don't particularly trust old wires/looms.
I can remember a vague lesson in tech college <cough - 30yrs ago....> about various metals and their electrical actions and reactions between different types of metals but it hasn't stuck in the brain very well over the years. Suffice it to say I'm not surprised to hear of different results of grounds on in-different or aged metals.
20 years + of metal chemical reactions..............?
 

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Discussion Starter · #17 ·
There should be a heavy gauge wire from the alternator to the block. The lighter gauge wire goes from a bracket on the manifold to (I think) a small hydraulic line retaining clip on the inner fender.
Alternator grounded to block, intake manifold grounded to the body nearby.
This was pretty much it! I hooked it right up to the brake line retainer on the body. The retainer's screw was very loose, so that explains why the wire freed itself in the first place.

And it turns out that rough idle was caused by a vacuum line I forgot to plug back in near the turbo during the clutch slave job. The car runs great now! Thanks everyone for the input. :cheesy:
 
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