Lost Charging Circuit

OK,
After going through the puddles WITHOUT a shield underneath, I expeienced a loss of charging.

I checked out ther following: Primary circuit wiring (yellow) and leads to starter solinoid, Alternator (was fresh rebuild by reputable shop 6 months ago) and battery.

Battery was funky and was replaced under warranty (not sure it was bad but it was low and wouldn't take a load). Wiring looked good except fusible link felt "soft" on wire from alternator to starter solinoid. Drones at Autozone tested alternator as OK.

Buttoned everything up again with new battery and drove home. On the way, I lost charge intermitantly a few times and headlights dimmed.

Any thoughts on where to look? I'm suspecting wire harness to alternator, probably the fusible link, although it rang out on resistance test just fine.

I may just "rebuild" this harness, since its one of the few I haven't on this gem.

Just because your alternator passed the bench at AZ doesn't mean it's any damn good.

If you go to a "chain" store, they're checking output voltage down around 1/10A draw. So, just because you're putting out a full, say, 14.2VDC, that's 14.2VDC at 1/10A - which is barely enough to run a decent Walkman.

I've had to work on those benches, so I know how they work.

If you suspect your alternator, and you want to get it tested, find a shop that does rewinds, and ask them to test it for you. They'll check voltag ena d current at max output - which is a far better test than just checking voltage at some arbitrary - too low - current rating.

Even with your passing the test at AZ, doesn't mean you're getting full output - it's not that sort of test. There's a reason I don't deal with chains for anything more complex than "open the bottle and pour..."

5-90 said:

Just because your alternator passed the bench at AZ doesn't mean it's any damn good.
If you suspect your alternator, and you want to get it tested, find a shop that does rewinds, and ask them to test it for you.

Click to expand...

Sorry, I forgot to mention that it took the alternator back to the local rebuilder today (excellent sho w/ 20+ years experience doing alternatorsd and starter rebuilds) for confirmation. Consider the alternator good.

Just making sure. I think you and I have talked about this before offline - and I also wanted to make sure anyone "new" coming along realises that they're not supposed to take those tests as the Gospel Truth... They suck, and they're usually wrong (for the reason I stated.)

Wiring looked good except fusible link felt "soft" on wire from alternator to starter solinoid.

Click to expand...

Since the alternator is proven good, I'd really suspect that fusible link. You can buy blade type fuse holders to replace fusible links now, but I haven't seen any greater than 50A. You'd need one equal to the value of the fusible link just to be safe......

Runnin'OnEmpty said:

Since the alternator is proven good, I'd really suspect that fusible link. You can buy blade type fuse holders to replace fusible links now, but I haven't seen any greater than 50A. You'd need one equal to the value of the fusible link just to be safe......

Click to expand...

Which is why I settled on ANL fuses, rather than MAXI. You have to "gang" MAXI fuses to get a useful rating for this sort of thing - while a single ANL will do the job.

5-90 said:

Which is why I settled on ANL fuses, rather than MAXI. You have to "gang" MAXI fuses to get a useful rating for this sort of thing - while a single ANL will do the job.

Click to expand...

Teach me about ANL and MAXI fuses. Is that like the big-ass old-school fuse I got with my Amp install kit?

On further driving the beast, it sorta seems like its charging, w/ Alt Gauge reading 14V. Then it will drop to 12V and eventually creap down to 9V.

I'm thinking the fusible link is the suspect. Anyone know what size the alternator FL is? My book is a bit far away.

Nevada City Sparky said:

Teach me about ANL and MAXI fuses. Is that like the big-ass old-school fuse I got with my Amp install kit?

On further driving the beast, it sorta seems like its charging, w/ Alt Gauge reading 14V. Then it will drop to 12V and eventually creap down to 9V.

I'm thinking the fusible link is the suspect. Anyone know what size the alternator FL is? My book is a bit far away.

Click to expand...

A MAXI fuse looks like the ATO/ATC "plastic blade" fuses - but larger. You should have several in your PDC. I think they top out somewhere around 80A, but I could be wrong.

An ANL fuse is also called a "wafer" fuse - it's a plastic wafer about an inch square, with two slotted metal tabs on it. It's retained by nuts on studs, usually.

ANL fuses can range from 60A to over 400A in ratings, and look like this:


They are commonly used in autosound (in ratings of around 100A,) and in marine mains applications (in ratings of 150A and up.) I've also seen them in industrial settings.

Fusible links used for the alternator output circuit seem to run right around 10AWG - good luck finding that... (The general rule for fusible links is to make it 4 wire gage numbers smaller than the wiring it's protecting - and ChryCo uses 6AWG for alternator output mains, battery mains, and start motor mains. Mostly.)