THANKS VOLVO thumbs down XC70 2001

[precopster]

Most important test is voltage with engine running at alternator positive post and compare this with voltage at jumper + terminal with engine running. Should be 13.6-14.4V with all accessories off such as head lights, A/C

[mrbrian200]

To test the alternator cable, measure with a voltmeter across alternator output post and the main (+) lug at the fuse/relay center. Engine running with all accessories turned on, climate fan running on high etc. measure for voltage it should be very close to 0 volts. I believe the allowable spec is 0.3v, the lower the better.

To check your main battery ground cable, again measuring voltage, key position II accessories all turned on engine off touch one lead of the voltmeter to the negative center/post of the battery itself (not the cable terminal/clamp), the other lead to anywhere on the chassis back in the trunk you can find clean/metal. I believe the same spec applies (around 0.3v allowable, maybe a little more but not much).

With a longer wire run around the outside the vehicle (voltmeter test leads aren't 10 feet long) you can test the positive main battery cable in the same manner between the (+) post on the battery itself and the positive post that the other end of that cable attaches to in the engine compartment.

[Georgeandkira]

Hello, You said, "... i took the car to two auto electricians before taking the alternator out, one said everything was fine the other said my alternator was faulty."

Again, this demonstrates you're far, far removed from the auto maker and swimming on your own. Too bad something as simple as a test of a charging system can't be had confidently.
I cleaned every ground connection I could find in my '02 when it reached "your age".

[darylrobert]

it was the Alternator that was faulty, the brushed were worn but ok i suspect it was the regulator or the the diode pack. anyway i just changed the whole unit and it has been running perfect since. I was just upset that there was no warning lights saying the battery wasnt charging. a simple voltage readout on the dash as an option in addition to the "distance to empty" etc would have alerted me that there was a problem.

on a side note i started the car without the alternator on and got all the warning messages including the battery light, so the alternator needs to fall out to trigger any warnings i think

[darylrobert]

Hello, You said, "... i took the car to two auto electricians before taking the alternator out, one said everything was fine the other said my alternator was faulty."

Again, this demonstrates you're far, far removed from the auto maker and swimming on your own. Too bad something as simple as a test of a charging system can't be had confidently.
I cleaned every ground connection I could find in my '02 when it reached "your age".

my old 1981 240 had a volt gauge vacuum gauge oil temp gauge, over the years Volvo has decided the driver doesnt need these things, i mean a turbo car without a boost gauge?

[Georgeandkira]

Auto makers probably think any gauge is a potential distraction.

How can a driver be distracted by a gauge when he's busy playing video games, texting behind the wheel all the while talking on Bluetooth?

While it is true most driving is done by ear and feel (RPMs and BOOST) it's good to have a reference when you feel something amiss.

Far and away the volt meter is the one which does the most good. Remember all those years Chrysler products had those limp amp gauges? They just wagged a bit this way or that.....completely meaningless.

What I'm seriously considering is a transmission (automatic, of course) temperature gauge.

[vtl]

Check that out: https://github.com/vtl/volvo-ddd It has lot more sensors on other pages/tabs, like transmission solenoids status, DEM sensors, A/C pressure, fuel pressure, fuel trims, battery voltage, etc All the parts are under $100, if memory is not lying.

[Georgeandkira]

Thanks for the link.
I wanted to tell daryl (the OP) my '02's interior lights began pulsing one day. I figured it was the regulator and rather than remove it in situ I took the whole alternator out and had it rebuilt.
Frankly, at 183,000 miles it was a no brainer.
There's a 3rd generation shop near me and I think the tab was ~$165. Not bad for new bearings, freewheel, regulator and I think they replace that ring too....and don't forget the groovy silver paint job.

[vtl]

Agree at this age there's no point replacing just VR if you took the whole thing out.

I did 2.5 alternators myself, quality parts were $100+, so $165 is really not bad.