Just asking alternator amperage

Hey just asking, I upgraded my stereo c/w with new amp, and also all this conversation about GR starters got me thinking battery and alternator draw? Anyhew went to fire up the ole girl this morning, deader than a door nail.?
I have a 1988 produced in Dec 1987, is there a way for a simple check if I got the 80 amp alternator or 100 amp. I thought they might of upgraded in 1988? How long are these things supposed to last anyway?

Mine is also a 1988 (Produced in 1987). Unless the Canadian market was different, my original alternator was I think only 80 amp. I went with a Landrover 120 amp and am quite happy with it. I had to buy it via Europe, because I could not find any in the US that came with the pulley.

I can’t remember if I needed a longer or shorter belt. Otherwise it fit no problem.

Brushes wear, regulators fail, run the engine, what’s the voltage? And under load? (Lights, fans etc.)

At first I thought my stereo amp upgrade was drawing too much power and the alternator was not keeping up. Turns out to be a dud nine year old battery.

That makes more sense. You have a voltmeter gauge, right? Very useful for such diagnostic purposes.

Nine years on a battery…count your blessings. I am lucky to get 4 or 5 on current generation of batteries

I’m coming up on six, that’s when I usually replace it before winter even if it’s working. 5-6 years is about what I usually get these days.

Not sure if it helps, but having it in the trunk must be a positive?

It should be but if you go with the correct protocol of boosting a dead battery you should place the last connection from live battery car to dead battery car of effective point on engine block. Hard to do with battery sitting in trunk (boot).

I always use a glass matt battery a put a battery tender on it to get longer life when the car is not used.

It doesn’t matter, that’s only to keep the spark away from the battery which can theoretically produce hydrogen & oxygen while charging. This is very unlikely nowadays, and any ground point is fine, you can also use a ground point on the master car.

Around here in Iowa with cold winters four years is to me a long life for a battery, that is if you want to be sure to get good starting… I don’t use my xjs in winter so perhaps it lasts longer that way…the auto stores here seem to have a two year guarantee. They no longer pro-rate the use of the batteries…just exchange if it dies.