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Rocan

Charging Woes...

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So to begin, some background.

I've owned my '02 since late September 2012. Since then, lots of fixing has gone on and the car is 20x better then it was when I bought it. The PO had work done to it, and a lot of it was good, but the things that weren't done were in poor shape. Of the things that had been done, the wiring harness had been replaced at some point (yet they didn't bother to re-wrap it or clean it before they put it in >,>) and the alternator had been replaced. In that time, I have had wiring problems (fixed most all of them by fixing poor crimp connections, bad grounds, dirty connections, and busted fuses), but as far as starting up every morning, no problems whatsoever.

This morning, though, that all changed. I had been driving a lot lately, mostly all city driving, and had no problems when it came to starting up yesterday (started and stopped the car at least 5 different times). This morning, though, I got a few cranks and then the well known "click" from the starter solenoid. Not having time to fix it since I had to drive out to New Jersey, I took the battery off, threw it on the charger, and took my fathers truck out. When I got back, I reinstalled the battery and began digging. Connections looked good at the alternator and battery (aside from my negative lead needing to be replaced because the terminal connector is cracked), but the two brown wires that connect to the blade on the starter was cruddy so I replaced it. Car started right away without issue.

Now comes the testing:

battery read 12.8 volts at idle, and reading did not change when revved (even over 3k, nothing). I checked the reading at the alternator, and again received battery voltage from both the visible posts on my alternator (not sure what alternator it is, see pictures) when using the alternator as a ground. So I'm assuming that means the alternator isn't charging. Either that or this alternator isn't tested in the same way as the stock '02 alternator (I'm using the charging system guide as a reference).

That's as far as I got. The only other bit of information I have is that at one point while reconnecting wires I noticed that the green wire for the charging system light was disconnected; at the time when i reconnected it was on even with the ignition off, and starting it did not change anything so I assumed that it was disconnected because it was connected improperly somewhere, disconnected it, and left it for another day. Now I'm reading that it could mean a diode is bad on the alternator. Would a bad diode mean I can still get a charge, just a poor charge? or no charge?

My apologies for the long post, I am trying to be as thorough as possible. Car is a 1976, running megajolt/Edis ignition if it matters. Starter is new from the PO as well.

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Just going over old service records... jesus these things are helpful! I thank the PO greatly for keeping great records... I continue to add to them...

First thing I notice: Back in 2009 in a note from a shop that worked on it...

"Defective alternator keeps on charge light"

DING DING DING.... Searching forward to see if the alternator was replaced after that and I don't find any records whatsoever aside from the voltage regulator being done.

So I guess my alternator is caput....

Now where should I go for a nice high output unit? I will eventually be running an electric fan, megasquirt, stereo, small sub, halogens, etc etc... pretty large amount of stuff, so I would like at least a 85 amp alternator. Preferably higher output since I do a lot of traffic driving and keeping the battery topped off is crucial since it is a daily. What is everyone running?

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I think the stock BMW alternators (85A) are a common upgrade - I went with a rushpower alternator based on a review from a member here, but haven't even installed it yet. Looks promising though.

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I got an 85A alternator for my tii from these guys on ebay:

http://www.ebay.com/itm/BMW-85Amp-Alternator-2002-1600-1800-2000-1966-1976-Generator-/350747794211?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ABMW%7CModel%3A2002&hash=item51aa329b23&vxp=mtr

Their alternator is superb and their customer service is excellent.

I have no affiliation with them other than purchasing from them.

Best of luck to you,

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Alt light on with ig off? First clue you have a drain on system, stop at Oreilleys first and have battery tested, didnt see how old battery was. With ig off put a volt meter on battery, see if any current is running, if so start pulling fuses to isolate circut, once found the fun begins, isolate the shorted component. Ifin alt, non fused, dash is fused, hope this helps, dinners burnin............

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I got an 85A alternator for my tii from these guys on ebay:

http://www.ebay.com/itm/BMW-85Amp-Alternator-2002-1600-1800-2000-1966-1976-Generator-/350747794211?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ABMW%7CModel%3A2002&hash=item51aa329b23&vxp=mtr

Their alternator is superb and their customer service is excellent.

I have no affiliation with them other than purchasing from them.

Best of luck to you,

X2 on this ebay alt. BNR is a fantastic seller and very helpful. Before I bought I had some questions and since they had their phone number listed I figured I'd call. Called twice about a week apart and both times talked to someone who answered my questions. I understand they have a shop so you can walk in and do business if you are local. Highly recommended.

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I believe the charging light being on = bad alternator diodes (assuming wiring is proper).

GL,

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I got an 85A alternator for my tii from these guys on ebay:

http://www.ebay.com/itm/BMW-85Amp-Alternator-2002-1600-1800-2000-1966-1976-Generator-/350747794211?pt=Motors_Car_Truck_Parts_Accessories&fits=Make%3ABMW%7CModel%3A2002&hash=item51aa329b23&vxp=mtr

Their alternator is superb and their customer service is excellent.

I have no affiliation with them other than purchasing from them.

Best of luck to you,

X2 on this ebay alt. BNR is a fantastic seller and very helpful. Before I bought I had some questions and since they had their phone number listed I figured I'd call. Called twice about a week apart and both times talked to someone who answered my questions. I understand they have a shop so you can walk in and do business if you are local. Highly recommended.

Thanks guys... Just placed my order now. I'll keep everyone posted!

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It is a very simple system, but you have to check everything.

1) battery grounds: one to the body, one to the engine

2) alternator ground: from the body of the alternator to the front upper timing cover (head) not to the battery; should be brown or black, not red, red means "hot"

3) alternator mount and fan belt: is the alternator "square" to the engine or are bushings bad, causing the belt to slip, is the tension correct, is the belt good

4) voltage regulator, Autozone sells VR 650 for about $30.00 it has the correct modular reciever plug.

5) wiring between the alternator and regulator: if you don't have the three wires with modular plugs (female) at both ends, you're asking for trouble, maybe someone here can sell you one. Both the alt and reg have three terminals, labeled: D+, DF, D-; they connect same to same, from the regulator D+ is also connected the lead to the warning light. Lastly in the wiring scheme is the red heavy output wire from the alternator screw terminal (B+) back to the battery (+)

now you can tell if the alternator is working or you need another, also available at autozone, not expensive (rebuilt bosch)

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Happy Easter!

Alternator came in yesterday... Awesome fast shipping and a beautiful product. Once the family left I ran outside and bolted in the new alternator before the rain hit. Piece of cake. Took all of about 10 minutes. Letting the battery get a full charge before I start it up so that I can avoid damaging the alternator. Unfortuntealy the rain came before I could cut open the engine bay wiring harness, clean it, and re-wrap it... It looks gross, and it really needs doing. Not having the wires running to the voltage regulator is great also since it means everything is just that little bit cleaner.

If you are considering getting this alternator, DO IT.

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Rocan, Can you take a photo of the fan clearance on that new alternator for me. Trying to find out why my fan is hitting the alternator bolt if its installed in the correct orientation. Thx, looks like I'll be buying the same one.

Cheers Girt

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Rocan, Can you take a photo of the fan clearance on that new alternator for me. Trying to find out why my fan is hitting the alternator bolt if its installed in the correct orientation. Thx, looks like I'll be buying the same one.

Cheers Girt

ill snap you one and post it by tomorrow night... its dark and raining out now.

Clearance is the same as stock alternator since it is a direct replacement. No issues whatsoever with getting it in and out. The tensioner bolt (farthest from the block) will contact the fan if you install it the wrong way. the head of it should be at the front of the car, with the threads inserting towards the rear. Mine touches the other way round.

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Thx, Mine hits the alternator pulley nut.

Any problems you can think of with using the 85 amp alt with the standard system? I know you have to ensure its got a good ground, anything else a problem with that much juice?

Cheers Girt

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Thx, Mine hits the alternator pulley nut.

Any problems you can think of with using the 85 amp alt with the standard system? I know you have to ensure its got a good ground, anything else a problem with that much juice?

Cheers Girt

There really shouldn't be unless if you had a short somewhere. It won't overcharge the battery, if that's what your wondering.

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So this morning, before work, I tore off all the worn and moily wire covering and re-wrapped it. Much better, though I still need to do the little bit between the firewall and the engine bay.

A few things I was wondering, perhaps someone could answer them... Originally the alternator B+ red wire runs into the harness and to the fuse box, and another thick red wire runs from the battery to the fuse box as well. I did a continuity test on those two wires and found they were connected. right now I have the alternator B+ wired directly to the battery since it is a nice thick gauge wire and I trust it more with the extra amps then the original wire. The other red wire must then be connected to the batter in order to provide power to the fuse box and the rest of the car. I am pretty sure this is correct; if I am doing something wrong by having the alternator connected directly to the battery, someone please let me know.

Secondly, while re-wrapping the harness and fixing broken connections, I noticed that there is a switch below the brake fluid reservoir that had the grounds cut off at some point by a previous owner. It isn't the brake switch since that is located at the linkage beside the booster; is it a warning lamp for low brake pressure? I have yet to re-connect the ground and see what light pops up.

See the pics below!

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