325e E30 NOT CHARGING

[hanta]

Hello my 1984 325e Has not been charging for awhile. The person I bought it from even bought it with the issue.

Things Iv'e tried:
- New Alternator (no change, but i see the mount has some corrosion, does it need that ground? see attached pic)
- New Battery cluster bulb (it doesn't come on with ign) Have a white back Cluster swapped in from unknown year 325e
- Different battery,
- Cleaned all connections

Bought a multimeter and not sure about all the steps of diagnosing, I've got like 30 tabs open and not sure where to start lol.

Thanks for any help, it is much appreciated.

[paultv]

If I'm not mistaken, there should be a blue wire connected to that spade terminal sticking out of your alternator - this comes from the dash charge bulb and "excites" the alternator to produce an output. The lead comes via C101 on the bulkhead pin 1 and also onto the diagnostic connector pin 12.

With the ignition on, earth pin 12 of the diagnostic connector and the dash charge lamp should light - proving at least that that part of the cicuitry is fine.

I'm sure Brian will show up with more detailed insights.

Paul

[Brianmoooore]

Blue wire should be connected to the other 'black lump' next to where the red wires are connected.
I'm not certain, but I think the unused spare terminal may be to connect an interference suppression capacitor.
Pull the rubber cover off of the terminal where the blue wire (hopefully) is connected, switch on the ignition, but do not start the engine. Use a piece of wire to connect the blue wire and terminal to a shiny piece of the alloy of the alternator. Does the battery warning lamp light?
Move the wire from the alternator alloy to clean metal on the engine, such as the lifting hook. Does the lamp light?

[hanta]

Blue wire should be connected to the other 'black lump' next to where the red wires are connected.
I'm not certain, but I think the unused spare terminal may be to connect an interference suppression capacitor.
Pull the rubber cover off of the terminal where the blue wire (hopefully) is connected, switch on the ignition, but do not start the engine. Use a piece of wire to connect the blue wire and terminal to a shiny piece of the alloy of the alternator. Does the battery warning lamp light?
Move the wire from the alternator alloy to clean metal on the engine, such as the lifting hook. Does the lamp light?

Not seeing any blue wire I have the two red wires and one black wire. Would that wire have been removed for some reason? DO I need to add it now? Damn

[hanta]

Could those 2 blue wires connecting to something below be related? dont think so just not sure what they are.

[biffer]

'Blue wire' on my '87 car is actually black plastic outer with 2 thin blue wires within.

[hanta]

'Blue wire' on my '87 car is actually black plastic outer with 2 thin blue wires within.

Hmm, so what is your ground then?

[hanta]

Soo I checked out my "black wire" and it was two blues wrapped in a black coating! I will be doing the testing and reporting my finds.

[biffer]

'Blue wire' on my '87 car is actually black plastic outer with 2 thin blue wires within.

Hmm, so what is your ground then?

My alternator earths through its mounting-bolt,like most,rather than having a separate earth-cable

[hanta]

so far it doesnt light up with either. Need to do better test though, Where is the lifting hook?

[biffer]

'tis thing sticking up in front of oil-filler cap,thatyou would use to lift engine out of bay.