3-Series (E21, E30)Chat relating to the BMW 3-Series from 1975-1983 and 1984-1991 line. Specific models: BMW 315, BMW 316, BMW 318, BMW 318i, BMW 320/4, BMW 320i, BMW 320/6, BMW 323i, BMW 320i. E30 Family models include: BMW 325e, BMW 325i, BMW 325is, BMW 325ix.
325i AT 180K 1987
Car will not turn-over. Battery good... will check ground next. Interior lights come on, and everything seems to work but will not crank.
I checked the AT interlock switch on the shift lever in the console. Light that illuminates selected gear position does not light... bulb is good.
Tested AT interlock switch by:
Volt meter tested interlock switch input wire (Grn/Yel) to brown (ground) wire of the Bulb while turning on the ignition switch. No voltage. I also tested the AT interlock switch - input to output wire... as predicted, no voltage.
Because the interior lights are on, and the AT interlock switch is also low voltage circuit, I would think there should be voltage present.... even if the ground on the car is not sufficient to power the starter.
According to the circuit diagram, the AT interlock switch input wire comes from the ignition switch, through a fuse (10 amp), and to the AT interlock switch.
Does anyone know where the 10 amp fuse is located? I have not looked for it as yet.
I'm guessing the ignition switch is the source of the problem. Without taking off the steering column plastic, is there an easy way to check this? Can I test the ignition switch someplace other than inside the steering column? How?
Any other common sources of "no crank" on 325i's. I'm ok with cars, but this is my first German brand... new to this car... my son just bought it.
Had battery checked, it was low but ok. Charged battery. Fuse # 10 (7.5 amp) was bad. Changed fuse. Car cranked and started immediately. Battery light on dash was illuminated red and stayed on.
It ran ok for about 45 minutes... test drove ok.
Then the headlights went very dim... less than half brightness. I suspect the charging system is bad. I thought the battery would last longer than 45 minutes, but maybe I'm wrong... the car would still run, but less smoothly.
1) process to check the alternator? I have volt / amp / ohm meter.
2) Common problems with the charging system? Has anyone had any similar problems, and what was the cause?
Any info would be helpful.
I saw a message on another web site about the alternator brushes worn, and how to check / change them. Sounds like a good probable cause. Will check that tonight.
Anyone think I'm on the right / wrong track?
Old man Fix It
You are bang on. Set it to check VDC, with the engine off it should read 12 volts, running it should read 13 or 14 volts. Also, make sure the batery termnals are clean. If they are fuzzy with rot, sprinkle a little baking soda on them and squirt water on them. Stuff a few rags around the batery to catch the wash off. Then take the termanls off and scrub them with a battery brush (less than 5 bucks at the auto parts store) then retighten.
Removed Alternator , and removed Regulator/brush assembly. One brush appeared to be worn out. Took alternator to local auto parts store... tested no good. Installed new regulator/brush assembly. Tested alternator again... no good.
Bought new alternator.
Trickle charged battery (2 amp) for about 4 hours... full charge. Installed new alternator in car. Reconnected battery... cleaned ground in trunck... cleaned posts and connectors (very clean to begin with). Tesed Alternator at connections.... 12 volts constant on B+ wire (big one).... tested D+ wire with ignition on... 2 - 3 volts.
Tried to start car... No crank condition... i.e. would not turn over at all. Closed hood (wondered if there was a hood interlock... can't find any reference to same in circuit diagram but saw a grounding spring on right front corner between hood and frame... what is it for, anybody know?
Anyway it turned over and started immediately !!! Idled great and battery light was off !!!
Turned off engine and it will not crank again !!! I'm back to square one. The alternator was bad (battery light is now off, etc.) but there is still an intermitent electrical problem in the circuit. Fuse #10 for A/T interlock has not blown again.
I could really use some help in diagnostic procedures starting from the starter and working back... ANybody know of same??
One way to tell for sure if your starter may or may not be the cause of the intermitent no start problem, it to get at the starter wires, there are two of them one large one from the batery the other smaller. Pull it off and take a test light to it. While some one turns the key. With the wire off the car won't start or spin, however the light should flash on and off each time that person tries turning the key.
I would check for a poorly-installed alarm system as well. You may have an intermittant starter kill caused by a malfunctioning or incorrectly installed alarm. My E30 was a wiring nightmare because of poorly-installed aftermarket components...
Well it's now starting everytime... but the radio did not have power last night... but this morning it started first try and I listened to the radio.... the gremlins keep jumping around... these are both new problems.
My son has owned this car for about a year.
It does have an aftermarket security alarm system... thanks for the thought. I'll see if I can take it out... have to see if my son will agree. I never have trusted that alarm system.. already unwired the horn of alarm... drove me nuts.
I'm beginning to suspect the ignition switch in the steering column... all the power flows thru it... both radio and starter circuit... only thing I can think of that is common.
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