Battery not charging? Alternator grounding out? 1989 244

[Didntchaknow]

Hey again!

My old beautiful 244 has been sitting for about a year due to a strange running/starting issue. I've finally hit a spot financially where I can put some time and money into fixing it. The issue is as follows:

I charge up the battery. I attempt to start, the engine will crank and takes a little feathering of the gas to get going. If I turn the key without feathering the gas it will crank but not turn over. Once it's running, it idles low (~600rpm) and after about 1-3 mins, the car dies and the battery is drained. Back when the issue started, I replaced the battery and the alternator. Unfortunately, the issue persists. Today I tried a few different things to try and get it to run well, and tested the voltage along the way. The battery light is NOT turning on on the dash, only a check engine light in position II.

Here's what I tried:
-Disconnected one of the ground wires on the alternator (mine has two for some reason?). This changed nothing, and the battery still drained and the car eventually stalled.
-disconnected both grounds. This allowed the car to run for longer, and better, but somehow, made the alternator hot (9V)
-tested voltage on battery (13V) and voltage on the large red wire on the alternator(~9V)
-Removed large red wire. Car would not start.
-grounded the small red wire with a plug on it (exciter wire?). This made the lights turn on on the dash, including the battery light. It did not make the car run for longer.
-Replaced fuses on 13, 14, and 15. No change

From what I can gather, I think there's a messed up ground somewhere, since removing both grounds makes the alternator hot, and grounding the small red plug on something other than the alternator makes the lights on the dash turn on. I could be entirely wrong.

Is the alternator bad? Is the wiring bad? Is the problem elsewhere? Something completely unrelated to the alternator/charging system?

Unfortunately electrical is like wizardry to me, so I'm completely lost.

I look forward to your advice and knowledge!

[Vova585]

1. Remove baterry
2. Remove alternator
3. Bring both to the local auto store(advance, zone, pep...)
4. Ask people there to charge your battery and test(free of charge in my local advance).
5. Ask them to test alternator
6. Do you still have old alternator? If yes, bring it with you to test.
7. I would love to blame main ground, but logically speaking your starter would not turn if it was completely defective (you still might have voltage drop...). 2 ground wires to alternator? We'll i can see maybe your 2nd ground looks like oem(not a specialist in 244 at all so dont throw stones) since it is braided type that you can see on modern volvo cars as well. It will not hurt to inspect/clean main baterry to chassy connection and look into literature(Chilton manual or some online pdf) where and how ground goes from chassy to engine and inspect/clean/replace that connection.
If you have some time Paul is a great teacher

[essamattougui]

This is critical on 240s. The small red wire from the instrument cluster (through the charge warning light) excites the alternator to start charging.

If the dash warning bulb is burned out, the alternator won't charge.

Key on, engine off = battery light should be on.

Start engine = light should go off.

[122sPhil]

I had an alternator I could have sworn was bad , replaced it , still the same issue. it turned out ot be tha tthe case of the alternator that ground to the motor, it was not making contact to the motor itself.

also check your battery ground to body and to the engine. every electrical thing on the car repies on a connection back to the battery. clean it well.

on some 240's the wiring leads around the front of the engine , it can get oil soaked, Id follow that and see if there could be a rotten wire issue in that area.