My 1985 chevettes belt was squealing now my alternator isn't charging properly. I think I need to tighten the belt but I'm not sure I remember how.

It's your alternator belt...they run on the same pulley. Tighten the alternator belt some, and the squeeling will stop.

1985 WOW ! does it run at all ? if it does , check battery voltage, should be between 12---14 volts, check alternator also, a parts store can do this for you ! is your regulator outside your alternator ? cause most new alternators have them inside the alternator ! just thinking out loud, but stranger things have happened ! are these new parts the correct ones for your make & model ? battery terminals clean, tight ! make sure all GROUNDS are good ! very important ! what condition are your battery cables ? is your BELT good, tight, not slipping !!! sure your starter & solonoid OK ! not shorting out, from dirt, grease, oil, etc., all fuses OK! I think we covered it, take your time, go over what I mentioned, see it you find the problem, good luck !

Locate the belt diagram sticker in your engine bay. It should look similar to the following:


After you have done that, look for a pulley labeled t or tensioner. Then use a fitting socket on the tensioner nut to tighten the belts. Be carefuly not to overtighten the belts because they will snap in cold weather. If they are squealing or making noise check to make sure the belt isn't overworn or if there is moisture on the belt.

You need to have the alternator checked. The tachometer runs off signal from the distributor, but can be indirectly affected by the charging system. It may be as simple as tightening the alternator belt, but I would guess that the alternator itself is going bad. Alternators that are marginal in charging ability anyway (old) may just go bad under the load of charging a fully dead battery.

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

Your alternator is not producing current to recharge the battery. Check to see the belt is on and properly tightened. Make sure your battery connections are clean and tight. If the belt and battery are good, remove the alternator and have it checked for output. Most likely will need to be replaced.

It should be either just above the air conditioning compressor, or on the opposite side. It will have two wires coming out - a red wire ( 12 volt plus) and a black ground wire. The a/c compressor has metal fittings and rubber hoses as well as a clutch. No need to touch the a/c compressor. I changed alternators on my 300D models and 300 SD. They are very much the same. You will need to loosen the adjustment slider and physically slide the alternator to loosen the belt. Remove the wires from the alternator - probably a plug at the rear. If the car has a single serpentine belt the problem is more complex because so many units run off the same belt, including the water pump, fan and a/c compressor. Restoring proper tension is critical. The alternator swings in a vertical arc on a long bolt on the bottom or side that runs from front to rear.  Replacement is not difficult - hold the new unit in place while you insert and tighten the long bolt, then reposition the tension slider and tighten that bolt. The tension needs to be correct or else the belt will slip and squeal and your battery will not charge properly. You may need a crowbar the achieve the right tension while you tighten the tension slide. Instead of replacing the alternator altogether, why not just replace the brush on a round plate at the rear. Most alternator failures involve worn brushes. The rebuilders simply replace them and sell a "rebuilt" unit. Make sure you can get brushes and/or a brush assembly before you start.. Loosen the tension but do not remove the alternator. Remove the two small nuts that hold the brush assembly at the rear and slide it off. Replace with the new one.  Be sure you retract the brushes so they will slip back over the armature, and align with the retaining screws. Tighten them. Re-tension the belt and you're home free. I have done this on the road when necessary. Easier and cheaper than changing the entire alternator.

You need to replace the alternator belt.they have a bolt which you loosen the belt. the belt probably got loose because this "tension" bolt was not properly tightened. the noise you hear is the belt slipping on the pullies. to replace it loosen the tension bolt until it is lose enough to remove the old belt. replace the belt with one of the same thickness and length. Be sure to tighten the bolt to where the belt will have about a 1/2 inch pressing down on it firmly with your thumb. you may have to remove some other components ( the fan for example) to replace the belt but thats questionable.

Good Day
The glow plug relays are located on the right front shock tower. Remove the cover and you will see two relays If I remember I think they are round, but not sure.

Please let me know how you make out and if there is anything else that I might be able to help you with.

Cheers

check the alternator

the alternator is what charges the battery, if it doesnt work you need a new one