New here! 1986 Holiday Rambler Alternator

Welcome to the forum!

If your new batteries are in fact discharged, you need to recharge them right away, as it will ruin them to sit totally discharged.

If you trust your mechanics recommendation, then someone should remove the alternator, take it to a quality auto parts store, to purchase replacement. They can look up replacement needed, and can see if theirs matches the one you have. Often times, you can trade your old one, getting a little savings on the new one.

Good luck, hope you enjoy your recent purchase. Holiday Ramblers were a good model, and the 454 a solid engine.

Jerry

You'll need a high output alternator. You have both chassis and house batteries to charge.

I can agree you want a replacement equal or higher output than original.
When it comes to alternators I have had much better luck marking mine, and taking it in for rebuild instead of part store factory rebuild.

NAPA auto parts has parts for old autos and such many times. I would try them first. Rock Auto online is the last resort for old vehicles. That engine however is some major auto engine from that time period. It wasn't made by Holiday.

Ok, thank you. I am calling Napa when they open. I like the idea of taking it out and taking it to Napa so they get the correct match. I am planning to add another Chassis battery, what is a good output for the alternator? We will be living in it and using a lot of power.

You should be able to get replacement locally without too much trouble. I would be looking for one with at least 90-amp output.
If you haven't done so, get a new set of belts at the same time.
NAPA is very pricey!
I would take to a location that performs alternator bench testing. O'Reilly's and AutoZone offer this service.
Around here they can get replacement within a day or so. Both offer lifetime guarantees on some.

If you will be living in the RV, the necessary power will not be coming from your engine alternator. The alternator may help keep the batteries charged while driving but once you stop, NADA! You will need a good battery charger, either a converter or an inverter charger larger enough to keep your house batteries charged. It may also be setup to keep your engine starting batteries charged as well (or not).

^^Above is a good point, especially if adding another house battery. All converter/chargers are not equal, and an 86 model may not have a quality converter, with smart charger. An upgrade to a newer model may be a wise decision, and not a huge expense.

You could post the brand/model you have now, to get more thoughts.

Jerry

More likely than not, you have a Magnatek 63XX converter. In the unlikely event it still works, the battery charge line output is only 3 amps.
You can keep the fuse box and converter body but you'll wan't to plan on upgrading the charger section. You can easily swap it out with a Progressive Dynamics (PDI) unit like a PDI9245 or PDI9260 and get the latest technology.
Check out Best Converter. They have detailed instructions on replacing your charge center.

Your alternator if original is probably around 80 amps. When mine went out on the road I replaced it with a 180 amp one which was able to charge my 2 6vGC house batteries as well as the chassis battery. If you go to a shop that rewinds motors and alternators, they can rewind one using your same case. I would check the alternator yourself before you remove it to see if it is actually bad. Jump start the MH and check to see if you can read 14v or so on the battery if so, it is still good. If not move up to the alternator output itself and see if it is outputting 14v's, if so, you may have a fuse or bad wire to the battery, if not you know for sure the alternator is bad. Just because you have new batteries doesn't mean your alternator is bad because the engine won't start. It maybe something as simple as corroded or loose wires to the battery or even a starter issue.