345 alternator

pbnjsellers · 06-02-2005, 11:58 AM

We are about to replace our inefficiently outputting alternator on the 85 345. When we pull it, since it may not be the right one installed, what should we be using to be able to handle charging the system with all of the usual running lights, etc.? What amperage rating is suggested, and should we be watchful of upgrading the wiring harness if more than the basic 65-amp (according to original manual) installed back then? Has anyone replaced one with a 100-amp unit, and had success with fitting properly?

74Argosy24MH · 06-02-2005, 04:17 PM

I think 94 amps was the largest in the 12SI alternators. They are an old design and don't have a lot of cooling capability. When the cars began demanding more power the CS series came out. These are adaptable without a lot of work but should have more than a single v belt to drive them. Some outfits will boost the SI to 150+ amps but don't really address the cooling and drive, if worked hard the alternator and belt both have short lives. Unless you have a really large house battery bank and draw it down the 94 amp will work. The marker lights don't draw much, the rest are about the same as what you have in any vehicle. You should use a heavier cable from the alternator.

John

ALANSD · 06-02-2005, 06:44 PM

I put a in 135 amp alternator and upgraded my battery isolator to handle it. The alternator has been great, run whatever you want and it keeps on charging. I got it and an aluminum cased heat resistant starter from www.4alterstart.com in Dallas. They build their own stuff.

87MH · 06-02-2005, 07:03 PM

Quote:

Originally Posted by pbnjsellers

We are about to replace our inefficiently outputting alternator on the 85 345. .... Has anyone replaced one with a 100-amp unit, and had success with fitting properly?

The '87 345 was equipped with a 105 amp Lestek alternator from the Airstream factory.

The original Airstream Manual lists their number as 1-800-433-7628.

59toaster · 06-02-2005, 08:05 PM

87-88 454 powered R20 Sub with towing package was 105 amp factory and should bolt in. 89 went to serpentine belt.

IPM · 08-06-2005, 09:41 PM

useful 12si info when visiting parts house

useful 12si info when visiting parts house

http://www.madelectrical.com/electri...elcoremy.shtml

fangthorpe · 08-07-2005, 08:45 AM

You can use a $100 Pepboys 105 A alternator from a pickup if you loosen the 3 long bolts and rotate the case so the plugs face up. It is unnecessary to order the $pecial RV alternator. Take the old one in with you to check the mounts and don't trust the book. 105 A is plenty and you don't need to change anything else.