9 replies to this topic

[robminibcy]

Hi My alternator bearings are on their way out, it still charges at the moment but it whines like a supercharger and you can feel the play in the shaft.

the car is a 79 pre a plus 998 and the alternator is a 16acr:

 

 I brought a new one from here in the hope that it would fit and be compatible but already I have a few issues. First is I have no idea what power rating it is, there are no meaningful markings or tags (to me anyway). Ideally I want it to be 45amp as I think that's what the old one was? can anyone tell rom these pics/ markings? new one is clean silver grey, old is black!

 

 

 

secondly it has an additional plug socket to the 3 way plup on the old one, what if anthing should go here? can it be used without?

 

 

Finally, the pully looks slightly different, whats the proper way of swapping them over without breaking anything?

 

Is this new alternator compatible or do I need to just get another like for like replacement?

 

Help much appreciated.

 

 

[cal844]

You need like for like!

[robminibcy]

thought that would be the answer! thanks anyway

[Captain Mainwaring]

You need like for like!

 

 

Why? I'm fairly sure I could have that new alternator running in  short amount of time

[cal844]

The new alternator may be the wrong amperage

[Cooperman]

That doesn't matter so long as it is 12 volt and the wiring can cope. If in doubt, run a second brown wire in parallel with the existing brown wire then if it is a high output unit it will take the higher charge rate. That's what I have with my 65 amp unit.

[Gremlin]

You need like for like!

Don't say things like this without being sure, You potentially costed this guy a new alternator and put a bad word against this forum

[robminibcy]

Right, thanks for the advice so far. im going to swap the pulleys over and try it see what the amps it produces. Question is ... how do I swap the pulleys  over with out breaking it! it is just a case grip the fan and undo the nut or is there more to it than that?

 

Also on the wiring side, the main 3 pin plug fits as per the old one although this new one has the additional single pin connection. Does this need to be connected and if so to what?

If it turns out it is higher output than 45 amp is it just a case of run an additional wire in parallel to the thick brown wire in the middle of the 3 pin plug?

[robminibcy]

sorry just re read your post regarding the additional wire Cooperman, yep got that then!

[dklawson]

Do not worry about the additional pin.   Be advised of the following though.  The red charge warning lamp in the car is not just am indicator, it is part of the circuit and must work.  The warning lamp is in series with the small brown/yellow wire in the alternator plug.  If you observe that the red warning lamp is NOT on when you turn the key to the run position with the engine NOT running, let us know and we'll walk you through some quick tests.

 

As stated above, if the alternator meets the demands of your car's use of electricity you do not need to match what was in the car before.  Cooperman has already advised you how to handle running an additional wire from the alternator plug to handle the additional output of a higher rated alternator.

 

The pulley nut can be difficult.  Everyone will have their own method of handling this.  My method involves using a strap wrench around the pulley to hold it while using an air impact wrench (what you guys call a windy gun?) to spin the nut off.  I have not found another method that works for me... the impact wrench is the only method I have used consistently without difficulty.