1G No battery light and no charging in '92 Galant

[sebas-1024]

Hi,

My car wouldn't turn over after a short drive last week, I used jumper cables to charge the battery a bit and get home but the alternator was not charging, I just had battery voltage with the car running. I changed the alternator belt as it had been making noises for a couple of weeks and was in pretty rough shape but that did not fix the issue. The bulb for the battery light seems to be Ok, and even if it wasn't the alternator relay/diode also tests Ok, I checked for continuity from battery terminal to B+ post, the alternator fuse also shows continuity, and I believe I properly checked the S and L terminals wires.

I suspect it's the alternator so I take it out and disassemble it, the slip rings show 3-4 ohms between each other but no continuity with the rotor core, the coil has continuity with all 4 leads, there is no continuity between coil and core, the diodes show continuity on one direction only with both the positive and negative plate, the brushes show continuity to where they connect and they're far from being worn. The only thing I'm unsure of is the voltage regulator as I don't know how to test it.

Would a bad voltage regulator cause the battery light not to be grounded at all? And also, is it likely that a voltage regulator gets damaged from driving through deep puddles? If anybody knows how to test it please let me know so I can check.

Sorry for the long post, I'm just trying to be thorough here, alternators are expensive so I'd like to be able to fix this myself without breaking the bank. Thanks in advance for any help!

 

[dwb]

Take the alternator to a parts store that offers free testing and see what the machine says.
Unfortunately alternators in DSMs are pretty much a consumable part. If you have to buy a new one, OEM is best, but like you said, expensive (if you can find one). Instead get a lifetime warranty from Autozone, NAPA, or Oriellys (I'd stay away from Advance Auto in light of their mass-closing).
There's also some parts like the voltage regulator available on ebay.

 

[sebas-1024]

Take the alternator to a parts store that offers free testing and see what the machine says.
Unfortunately alternators in DSMs are pretty much a consumable part. If you have to buy a new one, OEM is best, but like you said, expensive (if you can find one). Instead get a lifetime warranty from Autozone, NAPA, or Oriellys (I'd stay away from Advance Auto in light of their mass-closing).
There's also some parts like the voltage regulator available on ebay.

Mi idea is to fix it myself, I suspect it's the voltage regulator because it grounds both the battery light and the current coming from the alternator relay/diode, so it would make sense that both of those stopped doing their job at the same time.

I live in Venezuela so it's not so easy to just go to a store and get a warranty (much less lifetime) for any parts, that's part of the reason of why I'm trying to fix this myself. Sometimes I buy stuff from Rock auto and have it shipped, but if I have any issues after it ships then I'm on my own.

Might go for an Ebay voltage regulator but I haven't been able to prove that the regulator is faulty.

Thanks for the reply!

 

[dwb]

I've pieced together Frankenstein alternators using two cores that had different symptoms. One dead one and one that overcharged. I just put the voltage regulator from the dead one into the overcharging one.

I've also found broken solder joints between the coil and diodes (rectifier?). Worth checking.

 

[sebas-1024]

I've pieced together Frankenstein alternators using two cores that had different symptoms. One dead one and one that overcharged. I just put the voltage regulator from the dead one into the overcharging one.

I've also found broken solder joints between the coil and diodes (rectifier?). Worth checking.

Yeah, that's my idea, if I can find a broken down alternator with a working voltage regulator that is. All solder joints seemed ok so I don't really suspect those.

I'm going to check voltages on the S and L terminals with the car off and running, if those have the proper voltages then I think it's safe to assume that the voltage regulator is just failing to ground them and do whatever else it does.

 

[DSMPT]

Isn't the alternator charging the battery at all even at cold start? or it stops charging when the engine get hot? If you have a voltmeter, should check that. If it's charging at cold start but stops charging in some minutes, that's one of typical symptoms of bad regulator at the beginning.
I don't know about Galant but on my 1g, I had had a lot of bad voltage regulator cases. IIRC none of cases turned on the warning light in dash. You should log or monitor the voltage always with a aftermarket gauge while driving, that would be important for our cars.

This was my solution.

Where are all the 1990 GSX OEM Alternators?

Can someone drop your best links for an OEM alternator for my 1990 Eclipse GSX? Been digging in the forums but I couldn't find anything specific myself.

www.dsmtuners.com

 

[sebas-1024]

Isn't the alternator charging the battery at all even at cold start? or it stops charging when the engine get hot? If you have a voltmeter, should check that. If it's charging at cold start but stops charging in some minutes, that's one of typical symptoms of bad regulator at the beginning.
I don't know about Galant but on my 1g, I had had a lot of bad voltage regulator cases. IIRC none of cases turned on the warning light in dash. You should log or monitor the voltage always with a aftermarket gauge while driving would be important for our cars.

This was my solution.

Where are all the 1990 GSX OEM Alternators?

Can someone drop your best links for an OEM alternator for my 1990 Eclipse GSX? Been digging in the forums but I couldn't find anything specific myself.

www.dsmtuners.com

Not entirely sure if the charging condition changes based on the engine temperature, I did jump start it once after it had been parked for the night and it was not charging at all, the voltage was just slowly going down from 12.6 V, and the Battery light never turns on, not even with the key in the ON position before cranking the engine.

Might pull the trigger on that Ebay one, it doesn't look cheap like the ones I've found. Thanks!

 

[sebas-1024]

I've pieced together Frankenstein alternators using two cores that had different symptoms. One dead one and one that overcharged. I just put the voltage regulator from the dead one into the overcharging one.

I've also found broken solder joints between the coil and diodes (rectifier?). Worth checking.

I got a new voltage regulator (Figures 1 and 2) and I'm in the process of installing it into the alternator to see if that solves the issue, I guess you might know how it connects to it. It was soldered so I de-soldered it and was left with this in Figures 3 and 4, pretty simple I suppose. I do want to make sure, does it only connect on the single small pin circled in Figure 4? Also, any tips on how to get it to make a nice connection? It's my first time using a soldering iron and don't want to make matters worse.

Also, I was not careful enough and broke off the plastic insulator that goes on the B+ post, is that something that can be easily bought and/or replaced?

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Figure 1. New Voltage Regulator

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Figure 2. New Regulator

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Figure 3. Terminal in rectifier where regulator connects to (there's a lot of material there)

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Figure 4. Old Voltage Regulator

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Figure 5. B+ Post without insulator

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