Volvo Alternator/Battery Issue Diagnosis

[1990C4S]

2004 Volvo V70R, 200,000+ miles. I am regularly getting the red battery light. The warmer the weather, the sooner the light turns on.

Last week I installed a temporary voltage gauge to monitor my battery voltage while driving. On start-up I get 14.2 volts, it's all good. As I drive the voltage slowly drops, and below ~13.5 volts the battery light illuminates.

Eventually off throttle the alternator basically stops outputting voltage and I drop to the battery voltage, 11.9 volts. The higher I rev the engine, the higher my alternator voltage goes, but the warmer the car gets the lower my high end voltage gets, so eventually the alternator can't hit 13.5 volts and the red light is always on.

My battery is a decent AGM (4-5 years old), but the resting voltage seems a bit low, typically 12.0 volts when parked. Using an AGM charger brings it up to 12.7, but it drops down to under 12.0 after a few hours. These numbers suggest to me that my battery can't hold a charge above about 30% of the original charge level.

I think my battery is toast, and causing the other issues, or I have two issues. It seems odd that the alternator output is all over the place (I suspect the alternator is original, so >20 years old, and >200,000 miles on it, but the voltage regulator is two years old, and came from a replacement alternator O'Reily's sold to me that did not fit). But, the car starts right up with zero signs of low current.

Normally I would replace the alternator but it is is EXTREMELY difficult to remove (rad and power steering pump are in the way, it an all day job). I can change the voltage regulator with a couple of hours of work. But, a voltage regulator from Volvo is $285! (yes, that's just the VR), an alternator is over $800!. There are lots of Ama2on 'equivalents for $50, do I do all that work for a knock off VR?


Start by swapping out the battery? Or did my alternator take out my battery and they both need to be replaced?

[Baz]

You probably got your money's worth from your 4-5 year old battery, so if it were me I'd go get a new one.

Quick and easy first step for troubleshoot and aside from that a very good investment going forward.

I replaced mine not long ago and was glad I did.

I got an EverStart from Walmart. Easy peasey and a good price!

Good luck!

[908/930]

I think you have a problem with a cable or a connection, check your ground wire and the positive lead that goes to the alternator. A connection in the alternator could be another problem. If your battery starts the car then I do not think it is the problem.

[1990C4S]

I have 'sort of' checked my cables, just visually. I will disconnect and tighten them tomorrow.

I had not really considered that issue. Thank you for the suggestion.

Maybe the +12V cable on the alternator is the issue...

[Arizona_928]

Originally Posted by Baz

You probably got your money's worth from your 4-5 year old battery, so if it were me I'd go get a new one.

Quick and easy first step for troubleshoot and aside from that a very good investment going forward.

I replaced mine not long ago and was glad I did.

I got an EverStart from Walmart. Easy peasey and a good price!

Good luck!

+1 except the Walmart battery. I had my battery test good but when I was tuning the ecm, it would fail due to the battery…

[LEAKYSEALS951]

Originally Posted by 1990C4S

2004 Volvo V70R,

Normally I would replace the alternator but it is is EXTREMELY difficult to remove (rad and power steering pump are in the way, it an all day job). I can change the voltage regulator with a couple of hours of work. But, a voltage regulator from Volvo is $285! (yes, that's just the VR), an alternator is over $800!. There are lots of Ama2on 'equivalents for $50, do I do all that work for a knock off VR?

Your post got me thinking about my alternator- and looking on my car.

***Easy? No, but I don't think you'd have to pull the radiator.
Uncompress the acc. belt tensioner/remove. Take a pic to remember routing.
Yes- Remove the power steering pump. Potentially the two radiator hoses
(Both could possibly benefit from flushing anyways...)

And there would be the alternator. Two mounting bolts, the wires from the harness, and voila! Good to go.

Good time for new acc. belt, ps flush/radiator flush potentially, but not as hard as some things.

The intake on a 2004/5 is not so easy. All the moons on Jupiter are yours, except Europa, AND the intake manifold. Don't eff with that.

***I am a dentist so I am used to working in miserable places- ymmv.

edit also- Disconnect battery- Ignition with key inserted to start position "two". Disconnect neg battery in back. Then +. Keep key inserted. Reconnect battery when done.

Do it over weekend. Sat- undoing stuff, fitting new alt. Sunday- put it back together before you forget where all everything goes. Two smaller projects instead of one full pull.

R

[1990C4S]

Longer story: Two years ago, 200 miles from home my alternator failed. Friday night on a long weekend (maybe Memorial Day).

I bought an alternator from O'Reilly and drove to Harbor Freight. I made a dozen trips into the store, buying the next tool I needed to get the alternator our. I spent a small fortune there.

With the power steering pump off, and the rad hose off, the alternator will ALMOST come out. It will not come out unless you pull the rad, or maybe just the fan shroud.

Anyway, O'Reilly's sold me the wrong alternator, so it was a moot point. I was able to use the VR from the new alternator, and got it installed on my old alternator. The new VR solved my over-voltage charging issue.

The VR swap can be done without pulling the entire alternator out. But it's still a terrible job...especially in a parking lot.

[LEAKYSEALS951]

lalalalala (holding ears and not wanting to hear that)
I'd d/c the top engine mount and sit my fat arse onto the engine to move it back before I'd tackle moving the rad.

Good to know it's that tight. (or- not good to know)- And good luck!
R

[masraum]

Charge the battery to full charge then get it load tested by a FLAPS (or buy a load tester, lots available for $25-60 at AZN).

[masraum]

Originally Posted by 1990C4S

Longer story: Two years ago, 200 miles from home my alternator failed. Friday night on a long weekend (maybe Memorial Day).

I bought an alternator from O'Reilly and drove to Harbor Freight. I made a dozen trips into the store, buying the next tool I needed to get the alternator our. I spent a small fortune there.

With the power steering pump off, and the rad hose off, the alternator will ALMOST come out. It will not come out unless you pull the rad, or maybe just the fan shroud.

Anyway, O'Reilly's sold me the wrong alternator, so it was a moot point. I was able to use the VR from the new alternator, and got it installed on my old alternator. The new VR solved my over-voltage charging issue.

The VR swap can be done without pulling the entire alternator out. But it's still a terrible job...especially in a parking lot.

WOW, what a horrible story! I've replaced parts in parking lots and on the side of the road. It always sucks. But the alternator in that thing EXTRA sucks to replace, and getting the wrong one is just the cherry on top. I can't even imagine changing the VR while the alt is in the car. It sounds like a good candidate for a match and some insurance, LOL!

[1990C4S]

I felt like I was on Vice Grip Garage. It was terrible. Until it worked and I could drive home, then it felt great.

My plan B was buying one of those hitch platforms, a small generator, and a battery charger, then run the generator all the way home. It never got to that.

[pmax]

Originally Posted by 1990C4S

...
Normally I would replace the alternator but it is is EXTREMELY difficult to remove (rad and power steering pump are in the way, it an all day job).
...

[1990C4S]

That is not the alternator mounting for my car. That's a V70, and that's the alternator O'Reilly's sold me.

The V70R is different.

[1990C4S]

I will add one thing. Once I discovered I had the wrong alternator, I did not try 'everything' in order get the alternator out, there was no point. Once I realized my only option was changing the VR I did that with the alternator unbolted, but still in the bowels of the car.

Extraction might have been possible...

Overnight my AGM battery dropped from 12.6 to 11.8 volts. I think it's time to replace it.

[masraum]

Originally Posted by 1990C4S

Overnight my AGM battery dropped from 12.6 to 11.8 volts. I think it's time to replace it.

Hopefully, you don't later discover that you've got a big drain, but yeah, overnight 12.6 --> 11.8 sounds like a problem for sure.

[zakthor]

Can you try harder with checking the cables? Theyre not a thing you can check with your eyes theyll fail around the crimps or inside the insulation.

Drive and get the voltage to stop working then supplement the ground with a jumper cable.

[1990C4S]

Originally Posted by zakthor

Drive and get the voltage to stop working then supplement the ground with a jumper cable.

Of course Volvo had to put the battery in the opposite end of the vehicle...so a jumper is not easy.

Cable inspection/retorquing is later today. But I am also getting a replacement battery in a day or two.

[zakthor]

Originally Posted by 1990C4S

Of course Volvo had to put the battery in the opposite end of the vehicle...so a jumper is not easy.

Cable inspection/retorquing is later today. But I am also getting a replacement battery in a day or two.

Just running a wire is fine, not much current while car is running. If you ground right thing the problem will disappear instantly.

If you've been measuring voltage at the battery then from above it sounds like your battery is bad but just be aware that bad grounding can do really strange stuff and make it look like vr and battery are bad. Also it can kill your battery fast if it doesn't let your battery charge.

[1990C4S]

The repairs are ongoing. I swapped batteries from my AGM to a known good lead acid, I noticed the charging voltage (when it's working) jumped up 13.8-14.0 volts, which is above what I was previously seeing.

There is no sign of 'wiring' issues, all the connection points are tight and clean, I suspect the voltage regulator is the issue.

The alternator is out, it's going for testing tomorrow. There was a fair bit of 'oil' on the alternator, it's right below the power steering pump, but I have no oil or P/S leaks, so I do not know where it came from. I don't think that's the issue. (EDIT - mine looked cleaner than the one in post #12, so I guess that's normal). Also, the B1 connection to the battery was not supertight, but there was zero sign of heat, and the connection was very clean.

Given that failure on the car takes 10-15 minutes on a hot day, I am not sure what the testing will prove...I will see what the alternator expert says, and what he recommends for a new VR.

PMax - The alternator DID come out through the opening per your posting. It was very difficult (every bit of this removal is difficult) but I think that last time I knew the replacement unit was wrong, so there was no point in struggling to get it out.

[Baz]

Any updates?