My Eleganza's Autozone 100 amp (lifetime warranty) alternator is putting out 15.5 to 17 volts, and i've been meaning to get around to replacing it... Meanwhile, the turn signals stopped working. changed the fuse, all good, but it blew again within a day. hopefully getting a normal alternator charge happening again will solve this problem and save further troubleshooting.
More news soon, cheers
Greg
Los Angeles
76 Birch 78 Eleganza

My Eleganza's Autozone 100 amp (lifetime warranty) alternator is putting out 15.5 to 17 volts, and i've been meaning to get around to replacing it... Meanwhile, the turn signals stopped working. changed the fuse, all good, but it blew again within a day. hopefully getting a normal alternator charge happening again will solve this problem and save further troubleshooting.
More news soon, cheers
Greg
Los Angeles
76 Birch 78 Eleganza

Before you go replacing that alternator, up unplug the APC cable if you have one, or the flat 2 conductor cable that goes in the back of the alternator and make sure that the actual connectors have good tension on them. I had your exact problem last spring and I found that both connectors had lost tension over the years and were not making good contact. I only found this AFTER I traded in a good alternator for a replacement. It turns out the one I turned in was good all the time.

...I can see no reason to remove the isolator...

In my world of, repair after failure occurs, the less complex a system is, the easier it is to diagnose and repair. Fewer parts in assemblies fail less often (for the most part). It is kinda nice to have some redundancy in critical systems, but far nicer to have extreme reliability in primary systems. An isolater is a very robust device, last for years, have no moving parts, and on a GMC, sit right out there where they are easy to check. Hang a bunch more combiner wires under that same hatch cover, add battery disconnect marine switches, more battery cables, etc. and it rapidly becomes time to sit back and scratch your head. Simple systems are simply easier to service. My take anyway.
Jim Hupy
Salem, OR
78 GMC Royale 403

> I can see no reason to remove the isolator even with solar or other sources.
Actually John, i was advised by a couple different mechanics that since we were running a house battery bank that consisted of (4) Trojan T-145's, as compared to the more common bank of (2) Trojan T-1015's; that this would be too much for the 100amp alternator and/or its usual wiring.
Although i imagine there might be an upgrade or a work-around for this, at the time i just took their advice...

> Also you hardly need the 100 set up to only charge engine.
yes, i figured it might be overkill... or that it had "head-room"...

but considering the dual air pumps, the air conditioning, headlights and marker lights,... Would it really be worth it to downgrade to a smaller size alternator? And is there one that fits the current bolts and pulleys, and is easily available from national auto parts chains (autozone)? but mainly, is there any gain to be had on efficiency, or reduced stress to the engine?

> Not sure hiw you wired things when you dtiched the isolator. Lack of sense cable would cause overvoltage.

This is what im going to look into right now... thanks!

Greg

In my world of, repair after failure occurs, the less complex a system is, the easier it is to diagnose and repair. Fewer parts in assemblies fail less often (for the most part). It is kinda nice to have some redundancy in critical systems, but far nicer to have extreme reliability in primary systems. An isolater is a very robust device, last for years, have no moving parts, and on a GMC, sit right out there where they are easy to
check. Hang a bunch more combiner wires under that same hatch cover, add battery disconnect marine switches, more battery cables, etc. and it rapidly becomes time to sit back and scratch your head. Simple systems are simply easier to service. My take anyway.
Jim Hupy