Charging Circuit woes

[ralley]

The charging circuit in the Zeppelin, a 1990/91 350, has failed again. I presume that it is due, as last time, to a failed fuse in the automotive fuse box. I'll be troubleshooting when it gets back from the shop, where it is having unrelated work done. ( It started and drove to the shop, about 15 miles, fine--but the battery was flat when I arrived.)

To recapitulate:

1. Last failure was due to a failed fuse in the automotive fuse box. (the fuse didn't look bad-but it was!!)

2. The diode package in the alternator failed as well. It now has a new 100 amp alternator.

3. It has a new 600 amp cranking battery.

So, I think she's telling me that there is a further electrical problem in the charging circuit. (2 blown fuses, etc?) Dash gage shows about 12V, but no more. Battery is not charging. Starts only with the house batteries.

I suspect the relay which combines the house and starting batteries, and I think I should carry a spare in any case. Anybody got a part number? If I order it now, it might get here before the Zeppelin gets back from the shop.

Rob

[swebster]

Rob,
Pretty sure this is a simple "Ford Style" starter solenoid. I've been able to buy them before by simply describing them to the guy at the parts counter.

Two large terminals on either side for the main juice and then two smaller terminals for the switch juice.

[ralley]

Thanks--I think you are right. BUT, the Zep is about 20 miles away at the shop. I suppose it can wait until I get it back. I haven't actually looked at the solenoid since I cleaned all the corrosion off the wiring and bolts in--March, maybe.
I also think a reasonable upgrade might be the installation of a continuous duty solenoid in the charging circuit, to avoid the voltage drop in the isolator.
The other possibility is to solder in a diode which will do the same thing--we shall see.
Thanks,

Rob