Need wire diagram for a 1994 Buick La Sabre, car's not charging and runs real bad on the take off. But with a fully charged battery car runs good.

Bad battery cables or loose cables could do thatI could not even boost my car so I towed it to a garage. They put new set of cables on and works good now.

There is no single diagram that gives you all that. I suggest you try www.AlldataDIY.com. You can access to the same diagrams the pros use for a single vehicle.

Check for power on the small purple wire at the starter while the key is being held in "start" position. If you have power, the starter is bad or there is a bad cable connection. If no power found, the rest of the circuit will have to be troubleshooted using a wiring diagram.

Go to web site WWW.HMASERVICE.COM and register your vehicle by VIN #. You'll then have access to shop manuals, wiring diagrams, technical service bulletins, illustrations, etc.
Provided there is no problem with the vehicle's wiring, find out what the charging current is to the battery. I've seen batteries which TEST good, but when under a CHARGE short out internally.
Example: Tested a battery & charging system on a Hyundai Elantra, the battery tested "Healthy" but indicated there was a CHARGING SYSTEM PROBLEM. I checked the battery voltage while the engine was running and found the battery voltage at 14.3 VDC (which was normal). I then used a Digital DC Clamp meter arount the positive (+) battery cable & found the battery was charging at 70 Amps!.. it was supposidly already fully charged (should have only been taking 4 to 6 amps when fully charged).

Best guess without looking/diagnosing the vehicle myself

Maybe this will help.

is this why you changed the battery,if so did you have the charging system checked first before replacing the battery.it could be the alternator causing the problem and the car running off of the battery until it gets to low on voltage to run the car.the other thing is you could have a voltage draw on the system as well.first you need to have the charging system checked out.

THATS SOUND LIKE FAULTY ALTERNATOR.BATTERY NOT GETTING NO CHARGE FROM ALTERNATOR.

Hi
'98 le sabre v6 3800. Dead key intermittent, ie no start, no noises.
New starter
new ign switch
earth checked
park inhibitor possible, but checked
where is the starter relay if there is one?
what else do you suggest?
Is there an immobiliser?

It's either a bad battery (low on charge) or a loose ground wire. If you are SURE that the battery has 12 volts (yes, even a low battery will run your lights, radio, door ajar chime, etc., but won't have enough to start the car). If the battery is fully charged and your volt meter shows 14.4 volts (fully charged battery reading), then it's a ground wire. There are two locations. The negative battery cable itself on the battery, and the location on the frame or engine where the cable connects to.If these are ok, check the positive cable connection on the starter.

Sounds like you a loose 12V connection at the relay box.Locate the relay box and when the engine is running wriggle the wiring harness or shake the relay bow and see if that's when the engine stalls. You may even have a bad / loose ground to the relays.