Alternator upgrade

[Laird Scooby]

Originally Posted by aardvarkash10

Or, invest in a solar panel charger.
.

We're currently experiencing weather likely to cause the second coming of Noah Ash!

See my comments about the rectum-fryer above!

[aardvarkash10]

sunny, calm and 22 degrees C here today Dave. Good thing - the entire country is covered in a dense black metaphorical cloud this morning...

Roger your rectifier suggestion - I hadn't mentioned it since I assumed the OP had done an output test on the alternator. I do know the clock in Moomin seems to be built with a movement designed to lift anchors on a freighter - it sucks many milliwatts 24/7.

[TonyS9]

Dave, AFAIK he is measuring the battery Voltage, not the alternator voltage.

The OP need to stop changing parts 'likley to fail', its perfectly diagnosable, he has a DVM.

You should get close to 14V at the battery with the lights on (higher when colder). 13.5V is poor.

What is the voltage at the alternator?

IF you have 13.5 normally you'll probably be <13 with the lights on, if you only drive the car for 15mins a day, the battery will not get fully charded and die eventually.

Use the voltage meter to work out the junctions with the biggest (or any measureable) drop. Should be <0.1V in a high current situation.

You will probably find all the cable have issues. You can use sand paper or dremel to clean off the ends of the copper and a nearby surface of the connector, then solder between them. Or drill holes for the battery crimps and fill with solder. You won't be able to solder the blacked copper surfaces.

[Laird Scooby]

We've got the meteorological big black cloud instead!

Have to confess, i thoght he'd done a proper charging test before changing the reg, seems not and the output of 13.5V on the new one is low, consistent with a fried rectum-fryer.

As for your clock, do you think maybe the mechanism has been weighted for the Northern Hemisphere by mistake?

Joking aside though, it's pulling way too much juice from the sound of things, i always used to work on a maximum drain of 40mA or less to iclude clock, alarm/immobiliser, stereo memory etc but even that was pushing it a bit. If your clock is pulling more than that on its own, there's something seriously wrong somewhere!

Another favourite is the boot/load deck lamp - often ignored and forgotten about as you only notice it when it's dark.

Not applicable to the Volvo 7/9xx models but certainly on things like Fords that have a permanently live cig lighter, they can go faulty and pull current (3-4A often) flattening the battery overnight.

If aftermarket power/cig lighter sockets have been fitted with a permanent feed though, that could be a source of trouble and i've even known a couple of hazard warning switches to go leaky and pull current too.

Favourite potential culprit on the OPs car is the alternator, it's a bit of a faff to disconnect the B+ lead from it each night but would certainly give an indication if i'm in the right area. Won't be definitive if it's not charging properly though, just a pointer that we might be onto something.

[Jebus]

What actual testing have you done to find it? voltage drop tests and a parasitic draw tests don't take long and would have narrowed it down, there has to be something to cause a draw, pullings fuses and unplugging components one at a time would find it, there are only so many things on a 940 that could cause a draw.

[940volvoman]

Jebus there are things that pull current that don't go through the fusebox,though?
I seem o remember some time ago that Fuse 5 was pulling the most current.I will need to check it again and report back.
With regards the battery Vs alternator voltage I added the three main extra cables,so there wont (or shouldn't be any voltage drop between the two.I also used the unused cable from the previous owners amplifier to connect the voltmeter,just to cover myself with regards voltage drop.Overkill?maybe.I will check the voltmeter readings tomorrow and report back....

[Laird Scooby]

Originally Posted by 940volvoman

Jebus there are things that pull current that don't go through the fusebox,though?
I seem o remember some time ago that Fuse 5 was pulling the most current.I will need to check it again and report back.
With regards the battery Vs alternator voltage I added the three main extra cables,so there wont (or shouldn't be any voltage drop between the two.I also used the unused cable from the previous owners amplifier to connect the voltmeter,just to cover myself with regards voltage drop.Overkill?maybe.I will check the voltmeter readings tomorrow and report back....

Shouldn't really be anything that doesn't go through the fusebox except the starter motor.

Just to remind us, what year, model and engine is yours Shaun?

Also, how much of the previous owners amp installation remains? I'd disconnect ALL feeds to that simply to eliminate it from the equation but see my comments further up about the alternator and a test to see if it's likely to be the rectifier.

By the way, did you want the details on the immobiliser?

[940volvoman]

There is no trace of the previous owners amp that remains.He took it all out except the cable which was neatly threaded from front to back alongside the other parts of the loom.I painstakingly unthreaded the cable back to the front end and ran it across under the dash to the relay and onto the voltmeter.What there are traces of though are tow bar wiring,both OEM and aftermarket.I know this to be true because I pulled a small trailer for a while and the indicator lights on the dash didn't operate.Just the aftermarket buzzer in the back.I believe a caravan was also towed because of the dual socket electrics.
My Volvo is the 1998 Celebration Estate which has the B230FK engine from new.

Shaun

PS there is no sign of an aftermarket accessory fusebox which would bypass the factory one (as I have done in my van)

[Laird Scooby]

Ah-ha! More clues! I forgot to mention towbars last night, if you have the supplementary (12S) socket, that supplies power for the caravan to power the fridge and charge the batteries in the caravan.
Chances are there's a split-charge relay somewhere as well. This and/or the supplementary socket could also be a cause of trouble.

[940volvoman]

Towbars,indeed!!
I replaced both sockets back in the summer,as they were both covered in the black plastic weather resistant covers.The supplementary one had lost its spring loaded cover and all the wires /terminals were rusted out.Completely.So I justcswapped em over ,again, to help things along a bit.
However the split charge relay and other associated bits aren't used,so could be removed.....

Thanks for the immobiliser info.Will reply by pm asap