im confused, also engine swap? 1988 325i

[Stijmonkey]

Ok I was on here earlier with some issues about my car but ive since fixed it and its been running well for about 3 weeks until last night, I noticed the lights where a little dim on the way home, anyway my battery was draining and it seemed like the alternator wasn't charging the battery but both the battery and altenator are new and the battery light never came on. So unless the battery is faulty I don't know what's going on,

Also I heard that you could swap the engine for a m5x I believe relatively easy so I'm wondering how easily and if anyone knows a price range for those engines?

[Stijmonkey]

I checked and found out that the battery light is burnt out could this be affecting the charging of my battery somehow? If anyone knows help would be much appreciated thanx!

[Rrrockhound]

I think that's right, a blown or missing battery bulb in the cluster will keep the alternator from charging.

[Stijmonkey]

Thanx, does anyone know if I just switch the battery bulb for another one say the oil bulb, until I can get my hands on a new bulb, will that get my car drivable again?

[bostogrun]

The charging system warning light is the only "idiot light" without a sending unit. It is wired in parralell circuit with the ignition switch. When you trun the ignition on, the charge lamp goes on but its grounded to the alternator. As the alternator begins to crank out voltage the ground wire becomes positivley charged becasue there is no negative pole, a circuit is impossible so the light is extinguished. Because its wired in a series parralell circuit, I doubt it would affect the whole charging system. It's very rare for these bulbs to burn out because they hardly get any hours on them like a tail or brake light would.

Did you test your alternator output with a volt meter? Is at least 13.5 volts? If it is not at this level that your problem. Also is your serpentine belt tight enough? A loose belt, usually the result of worn tensioner, can cause undercharing.

[Stijmonkey]

The first thing I checked was the belt and it was still tight, I haven't checked the alternator yet but that's because its new, I assumed it was the battery light because when I turn the key all the lights came on like normal except the battery light, and it didn't come on while I was driving and the charging system cut out, but ill get a boost and get it started and check out the alternator

[Stijmonkey]

So i just switched the oil light bulb and the battery light bulb and you were right its not that, i boosted it and still the oil light(the bulb that used to be the battery light) came on with the others but the battery light still wouldnt turn on, i started it and it ran fine i took a quick look at the alternator and the belt seemed tight and was turning the alternator fine i didnt get a chance to test it as it started raining pretty hard so i shut the hood and went to disconnect the booster cables as soon as i did the the car instantly died, am i missing something incredibly obvious like a blown fuse or something i know it still might be the alternator but then why wont the battery light come on at all? and i still dont think its alternator anyway because again its new

[bostogrun]

Why havent you tested the battery charging voltage? Are you getting at least 13.5 with the car running. Thats the easiest way to see if the alternator is good. If your not getting 13.5 volts or more you are good. Just because the alternator is new it could still be bad, slight chance but still possible.

Are you sure you hooked up those alternator wires right?