Volvo 480 Club Europe

I have this car up for sale at the moment but continuing to work on it. (trying to convince SWMBO to let me. Keep. It)

1992 volvo 460 turbo auto 1.7 with richmod

New issue: it has recently had a new battery, once a month I start it up to keep the battery and fluids all ticking over etc.

This week, I have started the car and let it idle. After approx 10 minutes from cold it starts spluttering as though there is no petrol. I jump in a jump on the throttle, it revs briefly then dies.

The weird bit: it won't restart, the dash is permanently displaying the battery symbol even when ignition is off and there is a buzzing when I try to start the car, all the lights go out. I have charged the battery on a charger and tried again, same thing. Half the dash is dead, no radio, fan works, no power windows working.

I have not tried to start it this morning yet. I was going to use the battery monitor on the radio to check the charge and see what it is doing if I can get it started.

Unfortunately I don't have my multimeter or oscilloscope with me, so can't do many electrical test.

I think the previous owner has left me with a new voltage regulator, so could it be that this is up the chute and a new battery has hid it for a while, and the batteries charge has now dropped below that which sustains the car?

Something I will try: start it this morning, replicate the problem. Use my Xc60 to jump start it, if it starts then it's a supply issue and points to the alternator.

Would you say my line of enquiry is correct, what else should I interrogate? And if you are in Lowestoft GB I'd like some guidance on the car in general, it seems messy under the bonnet.

Battery symbol on would indicate a failed diode pack - charge the battery,disconnect the alternator and see how it runs (potentially using the other car as a donor charger)

https://youtu.be/zRonaIw9iLY

So far I can confirm it has started without issues, once it is hot will be the point we find out if the alternator is in fact the problem, do you recommend a replacement if we think that this is the case?

Does this knock out the info centre BTW?

Cheers

Andy

So... here's one potential answer. Obviously, without testing it, remote diagnosis is a tad tricky....

jifflemon wrote: ↑

Wed Feb 12, 2020 8:54 am

Battery symbol on would indicate a failed diode pack - charge the battery,disconnect the alternator and see how it runs (potentially using the other car as a donor charger)

The symptoms you described could be the car simply running on and then out of battery power...

As it's a new battery, that's a good thing: However, alternators will NEVER fully charge a battery - this is what battery chargers are for. If the battery has been flattened, you need to get it on a charger.

If the Diode pack has failed (which is what it sounds like), the alternator itself could be what's drained the battery, so yes, replacing the alternator would be a good move.

HOWEVER..... I'd ideally like a voltmeter prodded and probed around the car!

I did a how-t0 on charging problems, which should give you a good starting point....

Fantastic, I will get my multimeter from work when I am next on shift and bring it home.

Is the diode pack separate to the alternator or is it built in? If it is built in I would feel better changing them both anyway.

The car runs and gets up to temp once the battery has been charged full and the alternator has been disconnected, with the Xc60 acting as a charger I was able to run the car for a complete hour without issues this way and it got up to temp.

I figure that part of the info centre circuit runs through the alternator and the idle is also high as a result of this? I have taken the dials out to address a speedo issue I have been having, the plastic has fallen off the cable so. It is no longer protected.

I shall read up your guide and see what other things it sheds light on

Anadinolin wrote: ↑

Wed Feb 12, 2020 11:46 am

Is the diode pack separate to the alternator or is it built in? If it is built in I would feel better changing them both anyway.

Diode pack (the rectifier) is built into the Alternator. It can be replaced, but to be honest, it's simpler to simply replace the alternator!

Did a quick ebay hunt...

Alternator - £63.33
Rectifier - £53

Replacing the alternator is a one off, one on. Rectifier is alternator off, disassemble, swap rectifier blah blah blah....

jifflemon wrote: ↑

Wed Feb 12, 2020 12:11 pm

Anadinolin wrote: ↑

Wed Feb 12, 2020 11:46 am

Is the diode pack separate to the alternator or is it built in? If it is built in I would feel better changing them both anyway.

Diode pack (the rectifier) is built into the Alternator. It can be replaced, but to be honest, it's simpler to simply replace the alternator!

Did a quick ebay hunt...

Alternator - £63.33
Rectifier - £53

Replacing the alternator is a one off, one on. Rectifier is alternator off, disassemble, swap rectifier blah blah blah....

it might just be the regulator? avaialable for £10 to £15 ?
but wait until full testing with voltages at various revs etc

PS but still need to remove alternator to fix the brush/regulator pack

he's got a regulator already - and they can be swapped in situ. (2 10mm bolts, one spade connector)

May be worth a shot, but I'd be 99% on the rectifier.

jifflemon wrote: ↑

Thu Feb 13, 2020 8:26 am

and they can be swapped in situ. (2 10mm bolts, one spade connector)

wish I'd known that, I pulled the alternator the last time to change it, but easier on a non AC car and warmer /less fiddly on the bench

if you've got AC, it's never an in-situ!

I have bought back an oscilloscope from work, so I will be able to check over the alternator issue tomorrow following the guide that was posted earlier

Will let you guys know results as I find them. Also anything handy that I can use the scope for? Such as setting up the idlel on a richmod ecu, I thought there was a procedure etc?

Cheers,

Andy