328 / 308 NO 14V but Alternator is good....Double HELP!

Just brought the alternator to the shop, they tested & it's 14V?????? Going to spend $50 - $100 to replace the 1/2 worn brushes etc. while it's out.

So as a summery (from earlier posts);
1. Running car w/ fully charged battery & only seeing 12.6V
2. After a week of 1/2 hour driving a day I get 11.4V
3. Can then starts having a starting issue (turn the key & get nothing).
4. Battery is 1 year old & I pulled it & have Auto Palace test it & they say it's good.
5. Battery terminals & cables to battery cleaned.
6. Ground point from battery disconnect cable to chassis brushed / cleaned.
7. The engine leaks at the cam seal so the alternator was oily (cleaning it & adding brushes etc.).
8. Belts seemed tight, not worn in 1 spot, or oily.

So what wiring should I be checking? Ground from engine to chassis, positive + sense from alternator to starter, resistance from connection at starter & sense w/ key on run (battery disconnected) etc.

Any ideas?? I don't want to have done the alternator pull on a 328 for nothing...aaagggg.

Brad in NH

 

Without having any specific 328 knowledge, I do have one idea. The first thing to check is the battery itself. Put your meter on the + side of the battery and touch the - lead to the plastic battery case and whatever it's sitting on. Obviously any reading would be bad (well, good actually since you'll have found the problem).

But your problem is likely the ignition switch, fuse box....the commonly mentioned 328 weak points.


Ken

 

While I am no electrical demon, here's what I understand:
- your alternator on the bench produces 14+ volts. Is the amperage output in accordance with the output chart in the OM? (there's a chart of shaft speed against alternator output which determines the operating spec)
- you don't seem to have seen this on the car. A related(?) observation is that the alternator was covered in oil.
- your car displays symptoms of the battery not charging. The battery has been validated as good by separate testing.
- you have not mentioned the voltage regulator. I'll leave someone more knowledgeable than me to comment on this baby.

so:
- put the alternator back on the car. test the voltage when the car is idling/and at say 1500 rpm. If you are getting 14.4 or thereabouts, you are done. If you are not getting the voltage, either the alternator connection via the starter to the battery is bad (test it for continuity) or the alternator is not grounding well (test this too in the same way);
- I'm am not sure how well the alternator would perform when covered in oil. While that spot can be pretty mucky, (forward cam cover leak?) you might need to put some heat wrap or a heat shield on it to keep the extraneous stuff out.

The only way I can see for it to be ignition related is if some of your accessories are constantly on and draining the battery. This may occur over a week, but when you first hook it up if the alternator is working you should see 14+.

 

It is my understand the normal output voltage on the 328 Atlernator is normally low--about 13.6V, not the 14.5 that almost all other cars have.
This 13.6volt figure has been discussed on this board before, but the manuals--Tech, owners, Etc. indicate 14V.
I'm sure some others will pipe-in, but it looks to me that the current output of you alternator is low and in my experience (VW Rabbit) this can be a mechanical problem like weak springs on the brushes (could also be oil on the armature/commentator). In my Rabbit, the alternator would read 14.5 volts, but the system would not stay charged. I used to have to replace the brush pack every so often--this was very easy to do with the alternator in the car.

Good Luck,

Mark
View attachment 328 Alt Specs Tech Manual.pdf
View attachment GT4 Alt output.pdf

 

Also, if you look at the pages following the one Mark pulled out you'll see the alternator output chart with shaft speed I referred to in my earlier post.

 

The alt had 85A / 14V noted on it & when he spun it up it regulated to very close to the 14V +/-. He measured the output & it looked good. The place I brought it to actually works on them, not a middle man. It could be some odd issue that got knocked back in while removing it. In either case I'll have new brushes, clean it all up, the rings looks clean / shinny & not gouged.

Before it goes back in I'll check the engine to frame ground, the continuity of the 2 wires form the alt to the starter & at the starter w/ key on (saw mention of an ohm resistance on another post. I just don't want to get it back in & hooked up & find out it's still not working. Taking that thing our once was enough for me..

Any other ideas of things to check just keep them coming.

Brad

 

Nah Brad, removing the starter is much more fun. Particularly when it fails after the engine has just gone back in...
Philip

 

When they test it, have them run it for at least 15 minutes. My buddy was having problems with the alternator (ND) on his 348 spider, and they tested and said all was fine initially, but once it got hot, the voltage dropped off....it needed a new voltage regulator after all.

Dave

 

If the 328 alternator is like the BOSCH alternators on the earlier 308s, the brushes are an integral part of the regulator, so replacing the brushes gets you a new regulator as well.

 

Thanks agian all. When I get eh call that it's done I'll make sure he reads the spec's posted before I take it & make sure he's run it for a while. In the car I never got anything close to 13V just after start up or 15 minutes later.

He seemed to think that the ring was clean & the brushes were 1/2 worn. It's possible that 1 of the 2 brushes stuck so it kept the ring clean but caused me problems. It this happened recently then both would still look 1/2 worn.

With the above work, some wire checking, etc. after installation & before I mess w/ the coolant I'll start it (it's on stands) to do a quick ckeck for good voltage (well before having an engine melt down).

Brad

 

Check the output wire and eyelet connector for signs of burning and or detereoration.Many times I have found that as an alternator packs it in it also takes the output wire(small wire on the back,takes a 10mm wrench) with it.Look for discoloration in the wiring where the eyelet is connected to the wire.it usually is obviously burned when this happens.You can also check this wire for excessive resistance. Tim.

 

Just so readers in the future see an end to this chain...
The alternator is back in & cleaning it up, changing brushes, running to get it how at the shop etc. it's working fine, 13.8V at the lighter when driving. Still not 100% sure it was the alternator but with how oily it was it's possible. I cleaned all of the connections & made sure they were tight. The ground form engine to chassis was also in need of a cleaning & could have possibly been the issue.

Now with good charging we'll see if the starting problem that I think was due to a drained battery not closing the starter solenoid goes away. I also changed to Mobil 1 in the transmission & 2nd goes in much sooner than before. Of coarse having the coolant our of the car for a week & 19 year old hoses I now have a leak & it's just below the plenum (that I wanted to remove & repaint but after this driving season). One more week & I should be good....

Thanks all!

Brad

 

If the starting problem does not go away, check the archives on the testarossa starting problems....they use the same solenoid as on the 328, and you could upgrade to the Ace branded one that steve magnusson recommends.

 

Did you ever find the problem ? My 328 is doing the very same thing