1986 Winnebago Elandan 454 P30 Alternator Swap

[zaa]

I'm just posting to share some information about an alternator swap I just finished.


1986 Winnebago Elandan 454 P30


My alternator was an externally regulated Lestek, 110 amp. I had been chasing a constant battery drain of about 120mA. Through process of elimination, I eventually found the drain was a wire going to the external regulator, mounted on the passenger's side, just in front of the wheel well. I disconnected the regulator, and found that the drain was still present when testing between the alternator charge terminal, and the battery wire. I'm presuming it was a bad diode, but rather than struggle to rebuild or replace the original, I did some searching, and found that the Delco 10DN model alternators were very similar.


I decided on an internally regulated 130a (95a at idle) alternator (712710SI) from here:
http://www.qualitypowerauto.com/item_8/Early-GM-High-Output-Alternator-internal-voltage-regulator.htm


The only change I needed to make was to drill a new hole in the rear support bracket, and add a couple washers behind it. Aside from that, it bolted right on. Because I don't have a battery idiot light, I did not attach anything to the connectors on the side of the case, only the battery wire is connected. It charges at 14.5v The current drain is now down to a much more reasonable 10mA, which I expect is the clock, and radio memory.


It is important to make sure you have a very good, clean connection from the alternator to the battery. Lousy connections can burn up diodes. Also, it's not a good idea to charge a dead battery with an alternator. Many people do it and say it's never caused them a problem, but it's something to consider.


Hope this helps someone else.


Z

[Rickf1985]

Thanks for the link, I could use one of their Mega amp units on my Jeep. The single wire setup is the way to go even on the motor homes, less wire means less problems.

[DaveVA78Chieftain]

Just remember that higher amperage alternators place more strain on the fan belt which was designed for the lower rated alternator.  Can result in early fan belt failure or slipping belts because they are to small for the application.  Thats why you see 2 AC fan belts on a Dodge 440 with AC (few and far between).

[zaa]

Just remember that higher amperage alternators place more strain on the fan belt which was designed for the lower rated alternator.  Can result in early fan belt failure or slipping belts because they are to small for the application.  Thats why you see 2 AC fan belts on a Dodge 440 with AC (few and far between).

Yep, that's right, and going with a smaller pulley can make it even worse. So far, I haven't had any belt squeal, but then, I've replaced a lot of lights with LEDs, and lower consumption devices.