1996 volvo v70 T5 Alternator fault?

suitslayer · Post by **suitslayer** » 04 Nov 2007, 17:27

Hello all

I'm new to volvo,

my son talked me into buying a Volvo 850 glt T5
so I went and bought a 1996 volvo 850 with a v70 engine fitted, I drove home 233 miles after buying it, since then My battery wont charge. I changed the alternator and still nothing!
I put a multimeter on the battery running and the voltage is between 11-v 12.44v when I rev the engine the volt goes down then up after the rev. I can only drive the car for no more than 3 min
before it cuts out with no power in battery. I changed the battery and still the same! I have checked the 2 wires on the back of the alternator and they are both making contact, with no breaks. im baffled by it all please could someone give me another option to try. I spent all me money on this car and im Gutted! please help! im sick of getting buses to work.!
do you think changing the Voltage regulator would help? and with the car being a 850 glt t5 with a V70 engine fitted would that be a problem for a ecu test?

tHANK YOU FORUM

Post by **MadeInJapan** » 04 Nov 2007, 17:46

No such thing as a GLT T5...one has a low pressure turbo (GLT on '97 model 850's...before this it was a non-turbo) and the other a high pressure turbo (T5) unless you're saying the engine is from a V70 T5 then it would make sense. Actually, if that's the case, you have a very strong engine and that should be good for your car.

Now for your problem....check all of the wires from your positive and negative posts on your battery including the clamps on the posts themselves. Also check the grounding points on the engine...there are a few bare wire strands that are tightened to the engine...namely one on the back side of the engine near the fire wall. If any of these are bad such as corroded or broken or sheared, it could be causing some strange drain or no-run condition.

Do you get any trouble codes? Is the check engine light on on your dash?

suitslayer · Post by **suitslayer** » 04 Nov 2007, 18:15

Thanks m8
my car Log book says Volvo 850 T5 GLT, but the replacement engine is from a V70 T5

I'm not fimilure with the dashboard as yet Ive had the car less than a week so the codes I will look for

I jumped into this forum head first! sorry. I do remember the last time I drove it I could see smoke coming from the bonnet, I pulled in and opend the bonnet and found nothing that looked burnt, but I could smell it more near the Alternator, and I could feel it was hot at the back of the alternator too. since then my battery wont get a charge even after changing bat and alternator!

Post by **MadeInJapan** » 04 Nov 2007, 18:27

Okay...just noticed you're in the U.K. Volvo's there are a tad bit different than what we have here, but generally things that you're asking are all the same. Anyway, welcome to the board! Myself and others will certainly try to help. BillofDurham is from your side of the pond is also a moderator here so he'll be most helpful to you I know.

You should be reading close to or just under a steady 14Volts from your battery with the car running. Did you get a rebuilt alternator? If so, it might be defective. I would say to have it tested in your car from the place you got it.

Okay, I came back and am adding to this post because I just thought of something else...smoke, and fluctuating voltage...hmmm, when you can see down into the area where the serpentine belt is (also known as the alternator belt) make sure it's not old, slipping or even oil is being spilled onto it...could be from an engine (usually a cam seal) leak. The tensioner for that belt could also be shot so the belt is not staying taunt as it spins....just a thought but worth checking out too.

If you're getting an oil burning smell (from your smoke description) then take the spark plug cover off (the one with 6 torx screws on top of your engine). It may have oil under there....very common and caused by a bad rubber gasket on the oil filler cap- no big deal. Replace the gasket (cheap) and you're good to go. If you can't find one to fit, just cut an inner tube rubber to fit. It's important that this is tight. They get old/hot and brittle after awhile.

There is much to learn about your car and you came to the right place if you're trying to save money maintaining this car of yours. These cars are fun, safe and generally reliable and really no expensive than other cars if you maintain them.

Post by **Ozark Lee** » 04 Nov 2007, 18:41

Does your battery light come on when the engine is running?

For that matter does the battery light come on when you put the key into position II?

As dumb as it sounds the alternator won't work if the bulb is either removed or burned out - it is also fused in the instrument cluster.

The only other direction I can point you in is the main overload relay. It is rare that they go out but it is always possible.

If you have not yet done so grab the factory service manual that is a "Sticky" at the top of the 850 forum page and, once you download it and unzip it, see the file named alternator and regulator.pdf.

Good luck with it. The charging system is actually fairly simple to diagnose.

...Lee

Post by **MadeInJapan** » 04 Nov 2007, 18:44

Ozark Lee wrote: As dumb as it sounds the alternator won't work if the bulb is either removed or burned out - it is also fused in the instrument cluster.

That's absolutely amazing, and yes, a very strange design. it's good to learn something new every day.

suitslayer · Post by **suitslayer** » 04 Nov 2007, 18:56

tHANKS Ozark Lee
I forgot to mention The thin wire that comes from the back of the Alternator I think the colour is red&white I followed this wire, im not to sure I think it led into a 4 pin plug that connects to the turbo? well I checked for a break in the wire and found there was no reading.
could this be the fault? or should I check it when the engine is running?
I never new a blown bulb could cause this problem or a bad bulb connection tell me more

cheers!

suitslayer · Post by **suitslayer** » 04 Nov 2007, 19:20

Thanks for that link to the pdf file
Im understanding more now. I have not checked a few wires ie) the red wire from the starter. I can see on the schemetic the red and white wire seems to split up 1 going into the SRS Sensor and the other going to the climate control. Im looking forward to checking all this out
thanks.

cyclmck · Post by **cyclmck** » 04 Nov 2007, 21:03

Turn the key to the on position, not running. The little wire at the back of the alternator should have power. If it does not have power the alternator will not be energized and will not charge. If this is the case, as a temporary fix, you start the car and jump power to the little wire and the alternator will start charging. Then you can figure out why there is no power to that wire.

suitslayer · Post by **suitslayer** » 04 Nov 2007, 22:00

Thanks I will try that
do I connect a live feed from the + terminal on the battery to the thin wire, with the other wire running into the plug? or should i disconnect and make up a piece of wire with a spade end, then connect it to a + feed ?
I take it that, the red & white wire gives the feed to the alternator and I need to find why its not getting it. this is all starting to make sense for me
after looking through the pdf manual and reading the feedback. I really am looking forward to messing with my car in the morning.thanks for all your help I will get back to you with any results I will try and take a few pictures of my botch job.