How do you install the fan, idler to alternator belt on the 3.0 2001 Montero sport

it will be leaking oil onto the belt
it should be changed with every belt change along with all seals and idler pulleys
when in doubt ot oil residue in the housing, change it out

1995-98 Models

1. Disconnect the negative battery terminal.
2. Remove the splash guard on the right side of the vehicle.
3. Loosen the alternator belt idler pulley.
4. Slip the drive belt off the alternator pulley.
5. Remove the four air conditioning compressor mounting bolts.
6. Remove the radiator fan and fan shroud.
7. Move the air conditioning compressor forward.
8. Disconnect the alternator harness connector.
9. Remove the alternator mounting bolts, and lower the alternator from the vehicle.

To install:

1. Hold the alternator in place and install the mounting bolts.
2. Plug in the alternator harness connector.
3. Move the air conditioning compressor back into location.
4. Install the radiator cooling fan and shroud.
5. Install the air conditioning compressor mounting bolts.
6. Place the drive belt on the alternator pulley.
7. Tighten the drive belt to the proper tension with the idler pulley.
8. Install the splash guard.
9. Connect the negative battery terminal.

Proper belt tension is important. A belt that is too tight may cause alternator bearing failure; one that is too loose will cause a gradual battery discharge and/or belt slippage, resulting in belt breakage from overheating.

images for 1999 Mitsubishi Montero Sport belt

Montero Sport Alternator Replace 1 of 4 - YouTube

? 2:13
www.youtube.com/watch?v=Dwp14p6vBRU
Jun 22, 2011 - Uploaded by JesseHafen 2003 Mitsubishi Montero Sport alternator belts pulley auto repair steps. ... My 1999 Montero Sport Limited has 245000 miles and now is giving ...

Replace alternator belt on 2001 Mitsubishi Montero YouTube

On the 3.5 engine, the parts book shows a regular V belt for the ac.
There should be an idler pulley you move to get the belt off and on.

brake light switch probably bad and probably is the idler pully.

FOR 3.0LENGIBE. PUTTING ON ALTERNATOR BELT YOU NEED TO LOOSEN LOCKING BOLT IN SLOT IN THE BRACKET.LOOSEN PIVOT NUT BOTTOM NUT USE A PRY BAR PRY AGAINST ALTERNATOR TO TIGHTEN BELT TENSION. BELT SHOULD DEFLECT 1/4 TO 1/2. FOR 2.4L ENGINE TO GET ALTERNATOR BELT ON YOU NEED LOOSEN THE PIVOT BOLT OR NUT AT THE BOTTOM OF ALTERNATOR , LOOSEN THE LOCK BOLT AND TURN THE ADJUSTER BOLT TO TIGHTEN ALTERNATOR BELT THE BELT DEFLECTION SHOULD BE 1/4 TO 1/2 INCH WHEN YOU PRESS DOWN WITH THUMB.

the squeal when you start is the drive belt, it is slipping on the alternate you have to remember that the starter is the largest load on the battery so when the engine starts the alternator goes into a full output mode so there is a lot of load on the alternator belt right after start up also this probably why you are having a low charge at idle the belt is slipping enough to allow the alternator to slip at low ingoing speeds, take a good look at the belt tensionor and the drive belt best guess is that you will need both a new belt and a new tensionor.......HAVE FUN

Please confirm to me but I believe the alternator is driven with the serpintine belt. If this is the case there is an idler/tension pulley that would need to be first loosened (I believe it is a 14MM) then at the top of the bracket where this pulley is mounted there is a bolt that you rotate to either loosen or tighten the belt (by turning this bolt you either raise or lower the pulley.
I hope this may have helped,
Tom

if it is anything like my 98 montero sport 3.0 all you need is a socket set, the tensioner should be close to the pulley near the alternator