halftrack78 : Extra plug on the Gen/Alt.???

Extra plug on the Gen/Alt.???
Post by halftrack78 on Sept 28, 2006, 3:44pm

Not being very familiar with the 230 yet, while cleaning up the engine compartment I noticed a waterproof plug on the backside of the gen/alt. with nothing plugged into it. Then I noticed another wire lying near it. Not knowing if I unplugged them on accident I plugged them back in. Then, the truck would turn over and not start. Unplugged them again and...No issues! What are these wires for??? She is bone stock other than a God awfull grey paint. Thanks again...

Re: Extra plug on the Gen/Alt.???
Post by brute4c on Sept 29, 2006, 9:13am

A pic would help here...are they the little metal tags on the wires with a number or letters on it?
This is a wire connection ON the alternators rear face? There isnt one there on any stock alternator I have seen.

Re: Extra plug on the Gen/Alt.???
Post by hiker on Sept 29, 2006, 12:58pm

I believe that you are talking about the voltage "feedback" plug on the alternator, for lack of a better term. I don't know why your truck won't start with it connected. It should start. here's an image of one of the stock 24v alternators with the discussed plug.

http://img153.imageshack.us/img153/9...tor24v3af4.jpg

Re: Extra plug on the Gen/Alt.???
Post by brute4c on Sept 29, 2006, 1:11pm

That wire, #468 on the stock alternator, is the Excite Wire...the wire that is needed to start the charging process. It is connected to the on/off switch as wire #27.

Might want to check and make sure that wire doesnt go to ground for some reason...also might want to see if the On/Off switch is bad...as it also feeds the ignitor...if there is an internal problem, maybe power cant get to the ignitor when this wire is hooked up....

Re: Extra plug on the Gen/Alt.???
Post by hiker on Sept 30, 2006, 1:16am

I was going to link to the wiring diagrams so halftrack78 could see what you were talking about.
I'm wondering if wire #468 is grounding under the alternator cover plate, maybe chafed. Not much protection where the wire pinches under that cover plate.
Thanks Brute4c

Re: Extra plug on the Gen/Alt.???
Post by halftrack78 on Sept 30, 2006, 7:54am

I have a key switch in mine that doesn't appear stock, could this play a part in it? I will try to get a pic on site soon. Thanks for the help.

Re: Extra plug on the Gen/Alt.???
Post by brute4c on Sept 30, 2006, 9:53am

The 468 wire, the one that connects there on the alternator, is known to chafe through right where that little metal cover is on the alternator...possible...

Then that wire goes through a factory sealed splice where it splits in 2...one wire goes to the on/off switch and the other runs to the spider harness...the feed for the gauges...these are both numbered as #27.

On the on/off switch....as it is mounted in the dash stock, there are 4 places for wires to connect...2 on the right and 2 on the left....the 2 on the left as you look at the dash from the drivers seat are numbered as #11...these 2 wires are the power in to the switch...they come from the wire that hooks to the starter switch on the floor and runs also to the alternator...the big one on the alternator...

The other 2 wires, on the right side of the on/off switch, are as follows:

Top wire is #12...power to the ignitor...this wire runs directly to the ignition housing and screws on the side with a large bronze colored cap.

Bottom wire is #27...the one that feeds the alternator excite wire, #468, and the spider harness, the gauges...

I would check for continuity to ground along those wires...none of them should have such...

I would also look at that switch and see whats up there...might be ok...might not...

Without that wire hooked up on the alternator, it wont start producing juice to run the truck and charge the batteries...if it is a stock type alternator it needs that wire!

I guess I should have asked before...how long has it been this way and are the batteries keeping charge?

Re: Extra plug on the Gen/Alt.???
Post by halftrack78 on Oct 1, 2006, 9:31am

Don't have an answer to that, have not driven it much at all, still replacing brake lines. It always starts, all the gauges, lights and switches work. I guess I will have to wait for more of an answer once I get a pic on here.