Scenicruiser electrical questions

[rampeyboy]

Guys, I have several thoughts floating around in my head this afternoon. My
charging system is not charging. It is also still positive ground. I don't think
my power requirements would require I run the big gear driven
alternator/generator. I have read the archives here and at GMC busnuts, and
still have some questions..

So, since I'm not charging, it seems this might be the time to convert to
negative ground, eliminate the gear driven alternator, and install a belt driven
unit. The idea of the gear driven one locking up and destroying my engine is not
attractive. So not only would I disconnect it, I would want to remove it and
block off the mounting place.

Is there a block off plate one could buy for this purpose, or do I make it
myself? Flat plate OK? Should I use aluminum or steel, and what thickness?

I am concerned also about the engine control switch. I read elsewhere about it
having a diode in the circuit preventing shut down if polarity is reversed?
Anyone hear of this? Anything else I should be aware of? My dash mounted temp
and pressure gauges are currently inop, so I'll have to cross that hurdle
diode/polarity changes or not!

Boyce
disclaimer, I posted this message elsewhere if it looks familiar but no response there yet, so am posting here for a larger audience..

[Busted Knuckle]

Boyce,
All good questions!
I'm pretty sure there are factory block off plates available. (Clifford would know fer sure!)
Yes if it were me I'd go ahead and change over to a negative ground. (save much confusion later and maybe $ if ever worked on by someone unfamiliar w/ pos ground systems! (think wet behind the ear portable computer carrying parts changers!)
I can't help with any of the rest of it!
  BK 

[rampeyboy]

Thanks BK! I'm wet behind the ears with anything diesel, and some things gas powered too!

Boyce

[boogiethecat]

Knowing nothing about the physical attributes of your alternator, I'm wondering if you  could :

Take the thing out and modify its drive gear - bore it out and machine it to include a bronze bushing and a shear pin (same way a lot of outboard motor propellers work)... so if it locks the pin shears and the gear just spins-  that way it won' kill your engine if it locks up;
Turn it's 6 diodes around (basically get new ones that are physically the same with different polarity) and get an external regulator for it, thus converting it to a negative ground alternator.
Then you get the best of all worlds without a lot of redesign and messing around...
Just thinking out of the box a bit...

[rampeyboy]

Sounds like a good idea. I will keep that in mind! Thanks!

[bevans6]

I have a couple of cam drive position blanking plates if you decide you need one.  Email/pm me and I'll send you one.

Brian

[rampeyboy]

Thanks Brian, PM sent!


Boyce

[TedsBUSted]

There may be a few more petty polarity sensitive circuits. I know that on an '04 there is a rectifier in the warning buzzer circuit. Maybe an electric speedometer circuit would be polarity sensitive?

The deciding factor for the alternator of choice will be the available alternator, and its mounting brackets, that are most workable. I'm curious what model alternator is being considered? I used to like to fit the simple compact factory brackets and alternators used with Ford/DD applications, for 8-V's that didn't need lots of amps in the charging circuit.

Or if it's desired to stay the original positive ground course, isolated frame alternators, which don't ground via the case and can be easily configured as either polarity,  are readily available at not much, if any, premium over an internally grounded alternator.

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[TomC]

Instead of blocking the drive off, I believe you can get a conversion to make it a two groove V belt pulley-then just power the new belt driven alternator off that.  Good Luck, TomC

[rampeyboy]

At the moment, I have no working buzzers, so like the oil pressure, and coolant temp gauges that are inop, I have some work to do! Maybe I should get all this stuff working before introducing another variable.
I'm not in a huge rush to make this change, just trying to get my mind wrapped around what's involved, and bring to light whatever pitfalls there may be!

Boyce