New cluster and still not charging 85' 325e

[ThomasE30]

So i've been fighting a charging issue for months now despite wanting to bring it to an electrical place to get the issue looked at, along with getting the shitty alarm system taken out, and minor other things. On my cluster that came in the car, it's a later model MotoMeter. I used to have the battery and parking brake light both come on around the beginning of summer. But all of a sudden a while ago, both stopped working. Now I have a hunk o junk that wont charge. I try and get out and charge and drive to keep it from sitting but I need to get this fixed. The new cluster i put in isn't known working by any means but I got it for free to try. I swapped over all the new bulbs from my old cluster I put in. The only parts on this cluster that work now are the green turn signal lights, not high beams, the orange backlight, and the fuel gauge works. It was very sunny out when I tested but i got a sun visor over me and the dash and still didn't see any of those red warning lights come on. Is there anything that would cause those to just not work at all? Any help is appreciated.

[reelizmpro]

If the alternator is faulty or not connected properly, the battery light won't turn on in the Key on position like it's supposed to. Voltage at the battery should be 13.7-14.4v while running. If not, then you have a problem with the alternator and not the cluster (unless you have an early pre-86 cluster).

[ThomasE30]

If the alternator is faulty or not connected properly, the battery light won't turn on in the Key on position like it's supposed to. Voltage at the battery should be 13.7-14.4v while running. If not, then you have a problem with the alternator and not the cluster (unless you have an early pre-86 cluster).

Right now I have a 85 325e VDO cluster and later model moto meter with the 6.5k tach. I am gonna take my alt to different places tomorrow and see if maybe the first place was wrong or something. The new alt that i installed, I went back to the website and I think it may be the wrong one as its got the ground points and ECS states that it isn't the right. Oreillys says its an 80amp one and i think it may be the rubber bushing one for the m3 or 318. Could this be causing it to not be lighting up?

[reelizmpro]

The rubber bushing 318/M3 alternator are grounded to the engine via ground cable. If you don't have the cable (probably don't) it won't work. It's the wrong alternator for the M20 anyway. You should be using a solid mount alternator.

[Jaxx_]

early clusters didn't have a resistor in parallel with the charging bulb, so if the bulb is out, it won't charge. Check that the small blue wire to the alternator (D+ terminal) has 12V when the key is in run (the motor doesn't have to be running). If this has 12V and is connected properly to the alternator, I imagine the alternator ground is faulty.

If there isn't 12V, check C1 connector behind the cluster, pin 16 (blue wire, to alternator) and pin 14 (green wire, from ignition switch, hot in run and start.) If they also read 12v, confirm at C101 and keep going down the line, or up depending on what you works.

Here's the diagram:

https://i.imgur.com/wMiOD7U.png

[ThomasE30]

early clusters didn't have a resistor in parallel with the charging bulb, so if the bulb is out, it won't charge. Check that the small blue wire to the alternator (D+ terminal) has 12V when the key is in run (the motor doesn't have to be running). If this has 12V and is connected properly to the alternator, I imagine the alternator ground is faulty.

If there isn't 12V, check C1 connector behind the cluster, pin 16 (blue wire, to alternator) and pin 14 (green wire, from ignition switch, hot in run and start.) If they also read 12v, confirm at C101 and keep going down the line, or up depending on what you works.

Here's the diagram:

https://i.imgur.com/wMiOD7U.png

Thanks a lot. Those PIN numbers are exactly what I need to search for voltage numbers and everything to hopefully find the issue. Or at least it’ll be something I can explain an expert so they can more easily understand the charging system if I bring it to someone to help me. Also are you saying that blue wire should have 12v when the key is in (car not running)? You said check to see if it does have 12v and then you said if it does there might be a faulty ground so I was a little confused on if it should or shouldn’t have 12v with the key just in.

[ThomasE30]

The rubber bushing 318/M3 alternator are grounded to the engine via ground cable. If you don't have the cable (probably don't) it won't work. It's the wrong alternator for the M20 anyway. You should be using a solid mount alternator.

Going to hopefully get this replaced. For now would I just be able to get a cable attached to the alternator, and then ground it to somewhere with clean metal, like how the m3/318 cars are supposed to ground?

[reelizmpro]

Going to hopefully get this replaced. For now would I just be able to get a cable attached to the alternator, and then ground it to somewhere with clean metal, like how the m3/318 cars are supposed to ground?

Yes. It will work if you ground the alternator to the engine.

[ThomasE30]

Yes. It will work if you ground the alternator to the engine.

Okay. Until I can get the right one, that’s what I will do. Thank you.