Alternator 90 amp or 115

[P944GUY]

Does anyone know the difference, and should i spend the money on a 115 amp alternator..What is the difference between that and a 90 amp...there's a few alternators out there...Hi-Test..who are they? the part number Bosch AL-170X doesn't say if it is a 90 or 115...but on a few sites they offer a Bosch 115 amp for the 944, which is a separate part number....Please give me some info...

I've been hearing a little bit of a grinding metal sound recently from my 87 944 na..and figuring it is the alternator going bad..been having some symptoms:

1. noticeably, the metalish grinding sound when a heavy load is on..a/c, fan on high, and then when rad. fans kick in...engine seems to really bog down..and when i have the interior fan on high it doesn't seem to blow as fast as it used to...

2. I have the upgraded wiring harness from renn bay for the headlights, which bypass the switch and lights are fed power right off alternator...which really bogs the engine down when I turn them on

3. noticed that the battery gauge is reading lower when all these things are on, anywhere from normal to below 10 mark..driving

4. but when everything is off, car running..no load, battery gauge reads a little lower than normal

5. battery is about 3 years old..and for Arizona that is amazing..usually only lasting about 2 years..using an Interstate Megatron

So if I take it somewhere to get checked can they check the load off the alternator and see how much power it is generating..

I've had the car since 2002 and have replaced everything but the alternator, and was my daily driver for about 3 years, until 1 year ago..now it's only a weekend car..however deplaced the VR back in 2003..all belts incl. timing were replaced last year...and this sound just started a few days ago...

alternator 90 or 115 amp....which one...is more power better...I am running an Alpine stereo with an amp...I think 400w, 100 going to each speaker.

[Vicious]

if you are running a amp i would go with the 115amp just for the extra power and ability to be able to add to the system without worrying about not having the charge power.

[John_AZ]

I bought the 115 amp for my 1987 924S in 2008. On line rebuilder, no core--$99 + $25 ship.

My reasons were the battery cables have increased resistance over the years, the electric fuel pump is many years old, the remaining wiring is old, the starter needed a bit more juice-have since replaced with a Bosch remanufactured.
The AC components in AZ need all the help the alternator and battery can offer.

No problems.

Your grinding sound could just be the alt bearings. The VR can be bad. Take it out and if the carbon contacts are less than 1/4 inch it should be replaced. Machine/sand the brass ring contact smooth. By the time you do all of this, you should just have gotten a new alt.
http://www.rangerovers.net/repairdetails/electrical/boschaltrepair.htm

GL
John_AZ
1988 924S + 1987 924S

[P944GUY]

I replaced the battery cables a year ago..about $190, and really made a difference in my electrics..grounds are super clean thanks to my dremel tool...

[AA_Ezra]

I cleaned all of my posts. upgraded the battery terminals. upgraded Alternator to Starter To Batter cable all to 4guage Monster Cable car audio cable. and cleaned out all the contact points and posts. and Rand a 2nd ground from the batte. and lastly Installed an Adjustable Voltage Regulator b/c stock runs at like 13.1-6 volts i cant remember for sure, but i do know that i jumped it up to 14.1-2 or maybe 14.4 i dont remember. but it definatly makes all the interior and exterior lighting brighter and it made the engine run a little smoother....And im running a 90Amp alternator (wish i had more) Pioneere Indash DVD player 1500 MTX mono block to a MTX 400RMs sub.... so its using anywh500ere from 40-500 watts and it keeps up just fine. but the lights do dimm if i crank it up. A Good enclosure Helps out alot so you get more output for less input wattage.

Regards
J