Alternator / Power Question

[Swaney]

Heya,

Got a question about my alternator. 4x4 is a Gen 1 Pajero.

My volt metre in the cab use to spring to 14.4V almost instantly on starting the engine up.

Now it very very slowly climbs to just under 12v and hangs there until im driving - after traveling about a 1km or so it slowly starts to climb to 14.4v. Once its at 14.4v - no worries it stays there (ie doesnt drop back down on idle).

Id figure if my belt was loose / need replacing then it would be slipping when hot under strain / high revs. And not so much at cold.

Latest toy I installed was a electric 7200lbs winch - have only used it under strain once - tried pulling my mates terrano up a small bank which it did very begrudgingly. The winch is direct wired to the battery with an isolator switch (which is off unless out 4x4'ing). Im guessing my battery / alternator are not up to the task of winching. From memory the winch draws 350Amp at full pull - which I doubt my battery / alternator is delivering. Have done some reading and it appears that the stock mitsubishi alternator delivers 75amps on road (so about 40amps at idle).

The winch manual said you should be using a 650CCA battery for winching applications. I have a deep cycle battery in there but have no idea of is cold cranking amps - (was with truck when purchased).

Questions are:
How do you know when your alternator is poked / on its way out?
Could it be a regulator or relay which is poked?
Is it better replacing the alternator with a high idle amp one? if so is there a cheap way of going about this - high idle alternators dont seem to come cheap.
Should I just get a bigger deep cycle battery?
Have done some reading on dual alternator setup and that sounds like a bit of a pain but could be cost effective- how hard is it?

Or am I completely barking up the wrong tree???


Thanks for your help.
Greg

[skiwi]

Hi Swaney,
First off I would remove your alternator and strip it down and check the brushes and give the whole thing a good clean. I't one thing most people forget to do but they do tend to clog up with all the shit you've been driving through.
If like you said the voltage has steadily dropped on your meter then it's a good guess that this could be one of the problems.
I would also seriously look at setting up a dual battery system for the winch system. Last thing you really want to do in a tough spot is use your winch and kill off you engine starting battery.

[Swaney]

You Legend - that makes a lot of sense.

Thanks & will do.