Ever seen an alternator fail like this? No charge, no battery light. Metro problem of the month! SOLVED!
 

I've had my winter beater Metro on the road for less than a week, and it's already sprouted a new exhaust leak and developed a charging problem! Awesome!

Let's talk about the charging problem - I've never seen one like this before.

Symptoms:

- Sometimes when I start the engine, the alternator is not charging. But sometimes it is (but much more likely not).

- On the more rare occasions it is working, if I do an engine-off coast, it may not resume charging the next time the engine is started. Alternator run time doesn't seem to change the odds that it will continue working on the next start-up.

The bizarre thing:

There's NO battery warning light showing on the dash when the alt is off but the engine is running. But it does show when the engine is off and the key is in the run position.

Because of that lack of warning, I first discovered the problem when the car radio blinked off (while driving - 100 km round trip). And when I next went to use the starter... nada. Battery voltage showed 7v! Battricide! Odd how the engine seemed to run well enough at that voltage, but the radio said "nuh-uh!"


I haven't done any kind of testing yet.

I'll check battery connections - but I don't think that would explain the lack of idiot light. Also, the engine fires right up when I turn the key (assuming 12+v SOC).

I will probably just swap the alternator with a known good one, but I'm not confident that's the problem. I've seen more than a few alternator failures in my life, but have never heard of an intermittent failure or a failure with NO idiot light warning.

Maybe idiot light only comes on at some lower voltage; lower than standard battery voltage?

Strange issue. I'd expect some loose connection based on the description.

Last time the alternator died on my Saturn it didn’t turn on the battery light. When I noticed it I had been driving for about 5 minutes, and first symptom I noticed was rather odd. I’d set my cruise control, and 2 seconds later it disengaged. Did that about 3 times and started looking at my gauges, noticed my scangauge said 12.6, so I turned around and went back home. If I turned the engine off and key on I’d be in the 11s, restarted and I was showing 12.5 at idle, 4000rpm would get me 12.7-12.8. Only way the battery light to come on was to turn the headlights on at idle, I wanna say voltage had to be down to like 11.9 to light it up.
Replaced the alternator, everything was fine. My guess is that one diode or feild went out but 2 were still trying

Yeah, my batt voltage got as low as 7 and no light! Funny that your cruise control didn't like low voltage - just like my radio.

I'll check the cable connection to the alternator too.

Check voltage drops while running. Alt output post to battery positive, and alt case to battery negative

Two problems? Is the light working and are they related?

The light works. With the engine off and the key set to RUN, it's on as it should be.

Intermittent alternator operations like that has been brushes in the past for me.

Should I hit it with a hammer?! I'm going to hit it with a hammer!

I've fixed starters that way before.

Give it a smack then replace it, but give it a smack just because you can!

hammersmack
 

I gave it a smack!

Results:


1) First couple of smacks (engine off, then started): nada

2) Second couple of smacks (engine running): immidiately started working! I could tell by the instant change in engine load, confirmed with voltage reading.


3) So I set off on a ~120 km round trip yesterday, but I brought a 2nd battery just in case. Good thing, because it stopped working about 1/3 of the way there and no additional smacks could return it to immediate service. However it spontaneously started working for a while while driving. I hooked the 2nd battery in parallel just to be safe.


I'll pull it off the car one of these days.



YKYAEM when ... you put off an alternator repair/replacement because the car sure gets better MPG when it's not working!

Install a switch when you change alternators. Then you choose when it charges.

Why not just ditch the alternator and get a decent capacity lithium deep cycle battery? Batteryhookup.com has a good selection.

Then deduct the cost of a new alternator from the cost of the battery. ;)

Why not install bicycle pedals connected to a generator so that exercise and electrical needs are covered? Throw some in the passenger side so they can do something useful. :P

Because your feet will be on the pedal properly DWLing and not using cruise control! :p

Pedals for the passengers though, hmmmm... :p

All good ideas!

I like the logic of deducting the cost of an alternator from a high capacity Li battery... but I already have a little pile of alternators that should work in the car. I'm just too lazy to do anything about it yet. (Getting the hammer out was significant progress!)

Besides, I'm currently spoiled and won't need my car until the weekend: driving my friends' Prius Prime for the rest of the week while they're away.

hammer
 

Best to use a rubber,rawhide, or brass mallet to rattle the brush.Less chance of fracturing the cast aluminum housing.

How about a hammer on a string that can be pulled while driving? :D

Sure, that would keep the other drivers in line, but what about the alternator?

Personally, I would like to see what a flux capacitor does with something that light, but maybe dilithium crystals would be easier to obtain--or perhaps plot particles?

That is what powers the TARDIS, right?

I found a "worked-when-removed" alternator in my alternator pile that I think will fit the Metro. It came off the Swift GT pars car I scrapped last year after we yanked the engine out for use in an airplane.

https://ecomodder.com/forum/attachme...1&d=1472573038

The guy who took the engine didn't want the old alternator... go figure!


I'll put it in this weekend.

Probably has four grooves on a short pulley, might not line up with your late brackets. You may have to swap pulleys if I remember correctly. I think the late cars have a longer pulley than the early cars to clear the crank sensor OBD2 crap.

Strike 2
 

^ Surprisingly, it the Swift alternator fit perfectly -- same mounting holes and pulley. Even the field control connector is the same. The diameter of the housing itself is smaller though - I suspect it has a lower output.

Unfortunately, it also didn't fix the problem - still no charging. Crud.

Next up: I'm going to pull the alt off the Firefly and try THAT one. Am I barking up the wrong tree at this point?

Should have done this sooner, but I also checked continuity to battery positive and ground through the cable & alternator housing. A-OK.

Plan C? D? There's a 2014 Mirage 5-speed for sale in Toronto with a $2600 asking price. I've never really liked this Metro.

Can you have the alternators tested somewhere? Most auto parts stores, at least in NY, will test them for free.

I'll have to look into that... Just called my usual store (Crappy Tire) and learned, "we used to, but not any more. Got rid of that machine." They said maybe NAPA does it. But they're closed today; will check tomorrow.

There used to be a local dedicated alt & starter repair shop and he would pop it on his test bench. But he's been gone for years.

Going to raid the Firefly now!

Take the whole pile! :)

"Will you test my alternator?"
"Sure!"
"Will you test one hundred alternators?"
"Manager!"

Edit. AutoZone tested my alternator the other day, you know, the last time that I broke my car.

Do you have a separate field wire and are you getting power there. If not is it fused?

Strike 3!
 

Firefly alternator tested on the Metro: still not charging.

Disconnected the field control wire, restarted, and voltage briefly hit 13.x, then went back to battery voltage.

I hope I haven't fried 2 good alternators...

As far as I know, only two of the wires on the alternator really matter. The obvious big one and the small one that goes to the ignition switch (might be labeled IG terminal). There should be battery voltage at that small wire with the ignition on.

Checking continuity on the big wire might not be enough. A corroded connection (maybe at the fuse?) might be able to pass enough current for a meter, but not for charging the battery. Try measuring voltage between the alternator main terminal and the positive battery terminal with it running. Voltage should be 0 or very close to it. Same with the negative battery terminal to the alternator housing. After typing that, I see 2000mc already suggested it. :)

I think I tested the equivalent: checked voltage at the positive alt terminal with the engine off and then running... no change. Battery voltage both times.

I'll check for corrosion at the other connections anyway tomorrow. Can't hurt.

I'm also calling about that cheap Mirage in the AM. :-P

Probably isn't getting reference/control voltage. See what you're reading at the harness with the ignition on (car doesn't need to be running).

Everything I've read says these are a "1-wire" alternators - they don't need control voltage to work. Just ground & positive cable to battery and sufficient RPM. That's why I've been testing with the control wire on & also disconnected.

Today's task: cleaning all connections & finding a shop that will test 100 alternators.

^ I think we may have a winner.

I put jumper cables directly from the alt body to battery negative, and from the alt positive output to battery positive, and it seems to work. Multiple starts. Field control connected & disconnected.

Maybe not a loose connection, but corrosion is the name of the game around here. I'm cleaning connections & grounds now.

I was never impressed with the ground cable running to the bracket on the transmission and the little body ground on the core support. I added bigger cables and bigger body grounds when I built my 91 1.3l Metro.

Buttoned up. THANKS, everyone!
 

Connections cleaned & re-connected. Everything seems to be working again based on multiple engine starts, though I haven't taken it for a drive yet... and after all that, I may not be driving it this winter anyway. (Still needed fixing, regardless.)

When I was banging my head against the wall trying to figure this out, a family member asked: don't you have someone you can ask for advice? And I said: of course! There are lots of smart people giving me good advice right now!

So thanks, everyone, for the help!

Mirage?

Comment on the last ChrisFix video:

Skills and required tools are accumulated over time. My son just took a month doing a valve job on his 4runner. He's now pretty good and fast on 4runners. Even brought back my tools, cleaned.

I now am fully skeptical of anything You tube.

Fumes: ask me tomorrow. :P

Piotrsko: and I am now pretty speedy at re & re'ing alternators on Metros.

I've seen more than a couple of problem alternators in all my automotive adventures, but have never seen one do this.

The bad connections appear to have been between the alt itself and the brackets. The battery negative post was a little cruddy too, but obviously not bad enough to cause starter problems.

The fun part: I also broke a bolt taking the known-good alternator off the Firefly to try on the Metro, so now I have to fix THAT too. Happily, that can wait until better weather.

Precient. :D


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