Electrical Problem

[FuriousCJP]

I have a 1984 318i 5spd manual coupe w/ M10. I've been having issues w/ my blower motor. Finally got the motor fixed but still need the resistor. Any way I was driving it last night. I had the headlights, heater, and hazards on. I noticed that the interior and dash lights were dimmed by this.
Ok no prob. Turn heater off and back on and noticed it affect the cluster. The rpms were jumping around from 0-4k. It was also make the car sluggish. I could accelerate just fine with just head and haz lights on but go to turn heater on and car would kinda pause/ jump ( choppy accel.) Shut the car off and batttery was dead. By the way pressing brakes with all 3 on made it even worse. Don't know were to start. I'm pretty bad w/ electrical. Any ideas guys???? Finally fixed heater now I can't use it:hitler:

[jlevie]

Sounds like the alternator isn't able to produce full output, probably from worn brushes.

[AndrewBird]

Definitely alternator. Make sure you charge the battery out of the car. Jumping it and letting the alternator charge it is bad for the alternator.

Why were you driving with the hazards on?

[603Racing]

That the way everyone drives 'in a van down by the river'. Now, how you drive an e30 in a van down by the river is beyond me.

Productive comment: If the blower is off and you have everything else in the car on (all lights, rear defrost, radio, etc) is there still a voltage issue? I would run the car with all the items you listed and check the voltage, also check the voltage with the car running and everything turned off. Then report back.

[Chuck C]

Check your alternator ground wire, and your engine ground wires, esp. the one at back of the cyl. head.

[FuriousCJP]

Why were you driving with the hazards on?

I do the paper route. Gotta have my hazarads on. You wouldn't believe the f*#king idots that drive at night in a van down by the river. Anyway here are the values, mind you the heat is on hi due to resistor and headlights is hi beams.( V =volts)
With nothing on--13.87v
headlights only--13.77v
hazard only---13.83v
headlights and hazard --13.73v
heat only--- steadily drop till 12.5v. It slows but continues to drop
headlights and heat ---steadily drop till 12.4v. It slows but continues to drop.
headlights, haz, and heat---steadily drop till 12v. It slows but continues to drop
With all 3 on, when voltage reached about 9.9v thats when the rpms start acting crazy. I should probably include that the 2nd time the heat quit (after I replaced the blower) it was a blown fuse. The fuse was fine the 1st three nights after replacing blower. Blow a fuse fixed it and here we are. You guys still thinking alternator??

[Chuck C]

Voltage regulator

[FuriousCJP]

Is the voltage regulator in/ on alternator or is it mounted separately? Is there a way to test it?? One more thing, My heat only worked on hi right. Well last night the heat worked on all settings. So my resistor isn't bad?????

[cabriodster87]

Posibly problem with high resistance in Heater Circuit/ Blower. Just a guess, but still check everything.

[FuriousCJP]

Wheres the voltage regulator??????

[jlevie]

The voltage regulator is also the brush holder. Two screws mount it to the back of the alternator. Pull the belt and check the bearings for noise. If good, replace the regulator/brush assembly. If the bearings are bad replace the alternator with a Bosh or BMW reman.

[FuriousCJP]

Ok guys either the problem got a lot worse or something else is wrong. I NEED HELP. On my way home from work all the lights, heat, etc. were working fine. Then the gets jumpy. I mean I would accelerate smoothly but car was jerking like i was letting off and then hitting the pedal. Or kinda like when you run out of gas.
When I left to go to my other job it was 10x worse. The pauses were longer. It would go a little pause 3-5secs then it kicked back in go a little farther pause.... It was 12-18 degrees out tonight. It happens in all gears. I can smell fuel( but that could be from reving when it pauses) Could the alternator make your car jerky like that????

[Jaxx_]

yes, if the coils aren't getting enough power to fire the spark plugs properly...

You need a new voltage regulator before you get stranded with a dead battery.

[cabriodster87]

I had a battery do that to my car once, it was actually shorting out internally.

[FuriousCJP]

Lets say it is alternator would it be ok to get it rebuilt by a shop??? Are bmw alternators different from domestic ones?? Has anyone had it rebuilt before?