Before I start the problem description I want to thank past contributors to this forum - I've read a ton of info, feel somewhat informed and have performed some of the testing suggested in other threads. I’m hoping that you guys can help me through the analysis and next steps.

A brief background on the car: Just bought a 1997 850 for my stepdaughter’s first car. Odometer was broken and black tape over the four righthand warning lights, a couple of which were on. After some issues started showing up, we got a Carfax that showed that the car had been taken in for electrical system scan several times four years ago, after which the car changed hands a couple of times. Needless to say, my wife is not optimistic but the girl loves the car and it’s growing on me as well.

The most pressing issue: The battery is not charging / holding a charge and has stranded a 17 year old girl three times.
The first time, it was close to the house, we thought she’d left something on so I jumped it, drove it home, charged the battery and she drove it for another week.
The second time, it was several miles away, I jumped it, drove a block and it died. Took battery home, charged it overnight and drove the car the 9 miles home. I drove it to Autozone, had the system tested and learned that the Alternator/Regulator was bad. I pulled the alternator (Thanks Robert!), took it back to Auto Zone only to learn that it tested good. Took it then to O’Reilly’s to be tested with the same results. Re-assembled everything, learned about the hazard flasher / security system thing, fired it up and it was good. Tested battery voltage immediately after starting and got 12.5 - a couple minutes later it was swinging between 13.5 and 14.5. When she came home from school the first time driving, I checked the voltage at the battery and it was 11.xx and dropping. Charged battery fully, took it into Autozone where they load tested it and determined the battery was good. Re-assembled everything and figured she’d be OK until I could have time to work on it as long as it got charged fully every night.
The third and final time was a few days later - the first really cold day of the winter. Instead of the usual start at home, park at school, start up and drive home, she had some running to do and had to start stop 5-6 times. Driving home, dash lights started popping off and on and the radio and headlights faded out and back on. Finally, the car died in the middle of the street. I hauled it home and did some more testing this afternoon.

Here are the tests that have been done to date:

• Alternator tested in car - showed good diodes / bad regulator.
• Alternator pulled from vehicle and tested on stand at two different shops - both times showing good.
• Battery pulled and load tested showing good.
• Voltage tested at battery shows very inconsistent readings. Occasionally, voltage shows 13.5-14.5, more often shows 12.xx and drops with usage (lights, fan, etc)
• Voltage tested at small red/white alternator wire shows 12.x V
• Voltage tested at large wire on alternator shows same V as whatever the battery reads.
• SRS light was the last one she remembered coming on before the car died. She says sometimes it's the battery, sometimes it's the Big Arrow. Always it's the dimming lights.

I’m wondering if maybe I have an alternator that works good when cool but gets funky when it warms up? Either that or a temperamental wire somewhere.

I really don’t want to dump large $$ until I’m fairly certain that I’m buying the right part.

I currently have $1650.00 into the car. If I can get the electrical fixed, I’ll need to replace the timing belt and the driver-side CV joint (I think).

Any ideas or further tests from the experts here will be greatly appreciated.

Thank you in advance for any help you can give.

Timster.

 

Why don't you tell us how many miles are on it? My guess is over 130K or so?

Brushes are likely worn out on the alt; when they're on the threshold of touching you will get intermittent results. Pull the alt regulator assembly (brush holder, regulator and diode pack) off the alt and see if the brushes are low to confirm.

Volvo Voltage Regulator (100AMP) Huco 9130518 | FCP Euro

 

I had the SAME issue earlier this year and what I did to solve the problem was take the battery cable connections apart at the battery and clean between the wires real good.

The battery positive cable goes bad, builds up corrosion between the wires and causes these erratic issues (especially in humid climates). Shops and suppliers change the cables, if you clean between the connections real good that can fix it about 1/2 the time.

 

The battery positive cable terminal can have two nuts on it. The problem is you might take it for granted if you tighten either down the terminal gets tight . . . wrong. One tightens the terminal, the other tightens the extra wires attached to that side of the terminal. My car died going down the road to teach me that lesson. That and all the time it took to find that loose nut


Clean is always good and like Rspi said above, taking things apart and wire brushing or sanding to make sure you have good connections is always a good idea. Then use battery washers and or dielectric gel to protect the connections.

Did you pull the alternator yourself or are you paying $$$ ??

Other problem area is at the fuse panel where the positive feed is.

The other thing since you're doing some of the work yourself is the ignition switch. I haven't come across it causing a no charge condition but the fact that you're having a number of different and unrelated idiot lights come up . . . well it makes me wonder. That is something the ignition can cause and the problem is they (Volvo) run a lot of stuff through there.
New part around 50 depending on your source and it can be done easily without pulling the steering wheel.

The trans up arrow (BIG arrow) is the one you want to make sure is just intermittent and is not indicating a transmission problem as that can be a big problem $$$$.
One thing to try is to slowly "row" the transmission a couple times through all the gears, gear by gear. It can help to make the neutral safety switch (PNP switch) function properly and eliminate that arrow if it's the switch that's causing it. Won't repair a bad PNP or repair the transmission but if the PNP isn't sending the correct info this can sometimes correct it. There is also info on taking it apart and cleaning it but for now, I'd just try the rowing and focus on the charging.

 

Thanks for the prompt replies! I'm on a time/cash line and your suggestions are appreciated very much. I particularly like the fact that most of them can be done w/o significant expenditure.
@gdog:
The odo is stopped at 145K, tracking back via the car fax we're guessing it's likely around 200K. The guy at Autozone said that the sticker on the alternator indicated that it was a remanufactured one.
I'm kind of kicking myself for not having disassembled the alt while I had it out of the car. I'm trying to decide if I want to tackle pulling off the regulator where it is or if I need to pull it out again...
@rspi:
The cables look to be original to the car and the cable ends are crimp-on. I like your suggestion since it requires time and not money ... Would you have a suggestion for what type to replace them with?
@kiss4afrog
I'll have to take a better look at the ends to see about how they connect. I appreciate the photo - I can see what you mean that both nuts serve a function.
The ignition switch is also a good call as I've noticed that when you start it, you have to back it off manually a bit or you have no gauges, turn signals or lights. I figured I'd have to replace it eventually but perhaps I need to kick it up the priority tree.
Thank you all for your input and links/photos. I'll have some time to poke around on it this afternoon so I'll try to get back with a full report. I'm leaning toward addressing the inexpensive options first and moving on up as I eliminate potential issues.

 

It seems like you've figured it out, really, but if it continues to be tricky, you could sure use a volt gauge installed so that you could recognize it's not charging, and then troubleshoot it when it's not charging.

 

I'd vote for doing the switch first. The cleaning of connections is always good and the washers and "goo" will keep your connections in better shape longer but if you have to jiggle that switch now I'd replace it so you're not chasing a problem it might be causing. It might not be the cheapest of the things to try but you already know it's bad and you surely wouldn't be wasting the time or money replacing it.

 

I did a quick Dremel cleaning of all contact points on both terminals. I didn't have time to separate the crimped wires for a thorough cleaning but figured I had to start somewhere so ...
Wire brushed, sprayed electrical cleaner down into the stranded wire bundles, re-assembled and fired it up. 14.2 V right off the bat and held. I switched the lights on, voltage dropped to 12.8. Turned the lights back off and it slowly climbed. I'm going to see what I can do with the contact at the alternator next chance I get to work on it (prob. sunday) and decide if I want to tackle un-crimping and cleaning the bundled wires.

I agree about the ignition - it definitely needs to be done. I'm willing to drop a hundred or so in parts to fix the electrical but if I can't I'll probably cut my losses and offload it. I'd hate to do that because the car is rust-free and solid, tires are practically new, etc.
I remain optimistic!

Oh - I included a couple of pics below. I'm assuming those are factory original battery terminals? Pretty cool, actually. They tighten without putting any torque on the post.

 

I had a similar issue with my previous 850, and I ran an additional cable from the alternator directly to the positive terminal on the battery. Never had a problem after that.

 

Those do look original and I did NOT take the crimp apart, just took all of the nuts loose, etc., and cleaned all the wire ends. My guess is, if you (or I) cut about 1 inch off the ends and installed new ends we would be good to go for sure.

I get the same results, but less at the top. 13.4 without lights, 12.6-8 with lights. No starting issues since the cleaning.

After you have the connections all cleaned up, you can coat them with spray or something.

Unless you are having some multiple electrical issues with the car and the key jiggle helps, I would NOT change the ignition switch.

 

I plugged in my voltmeter to the cigarette lighter and measured 12.58V before starting. Checked directly across the battery and it matched the voltage.

Started car (Service engine light on) 12.59 V after starting at Idle
About one minute later… Service engine light off and Voltage 13.8 at
approximately 1500 RPM. I drove around for 1/2 hour or so and observed the following:

2000 RPM

• No light or fans...............13.9
• Heater Fan on high..........13.6
• Headlights......................13.7
• Headlines + fan...............12.32 with slow drop

Parked at Idle (1000 RPM)

• Heater Fan and light........11.7 and slowly dropping
• Fan and lights off............12.48.

Now good and warm, I thought I'd re-test
At 2000 RPM fans and lights off 13.85.
Just in case RPM makes a difference, I figured I'd try slow cruising.
Sustained 25 mph (1500 RPM) consistent charging voltage around 13.8 to 13 nine

End of test, car off - constant battery voltage 12.7.

I'm planning on doing some general googling on other car sites to see if that is normal but I thought I'd post it here in case anyone wanted to weigh in.

timster

PS: Please enjoy the attached photo of my redneck charging system analyzer.

 

Very nice. LOL

It sounds like the voltage regulator is weak or bad. It should NOT jump around like that but mine does the same thing. And yours is newer/rebuilt so it shouldn't be. May be the cables.

Quick note, my ground straps on the back of my motor are corroded. Some guy seen that in one of my video's and told me to change them because that is bad for my charging system. I will likely change them tomorrow, I have replacements in the back of the car.

 

Is it a service engine soon light or the check engine light ??

Service engine soon is for oil changes and would have no impact on what you are doing or testing.

 

Good for you! Diagnosis is good.

 

Unless you have a wiring problem someplace with corrosion or some sort of bad connection that is "fooling" the regulator into thinking it's doing a good job it sure looks from your results that you have a failing regulator on that alternator.

 

Went smoother than the first time. Glad I pulled it as I found out that two of the bolts I'd put in had loosened and backed out - one of which ran itself into my nice new serpentine belt. (See first photo below) It grooved it on one side - I'll likely replace it but hang onto it in just in case.


Brings to mind a question:
Do you guys use any Locktite compound when re-assembling? I thought I had them cranked down pretty well but two bolts eased out in a week of light driving.

Anyway - after getting the alternator out, I pulled off the cap to look at the regulator. I've included some photos below. One thing that I noticed was that the brushes were wearing very differently as you can see in the photo. The shorter of the two brushes was around 1/8" (.130 actually) and perceptibly moved differently than the longer one. Also, there seemed to me to be some evidence of significant heat. I had intended to replace only the regulator (around 60 bucks) but gave the alt shaft a spin and felt like there was a little roughness... so I guess I'll be into Autozone for about 200.00 tomorrow. At least I get a lifetime guarantee on the alt so ...

Finally, I included a photo of my own system for bolt organization. I've never been good at holding locations and steps in my head without some visual cues - this works for me.

Again, I appreciate all the suggestions from you all and look forward to hearing your opinions on thread locker.

Timster.

 

Do you see wear-limit lines in the brushes? If no, my guess is they're worn off. Those things look like nubs of their former selves..

RE: bolts; you can use thread locker if you want but I only use it where the manual specifies it. Properly torqued bolts will not back out like that; something was wrong on the install.

 

If you use a thread locker make sure you use the light duty stuff. If shouldn't take too much to hold them in there properly. Seems strange they loosened up unless something was a bit cocked and you felt it tighten but then the mount shifted ??? Just guessing.

That regulator looks a little cooked. On your tensioner it would be a good idea to lube it since you have it out. It's an actual maintenance procedure.

LUBRICATING AUXILIARY DRIVE BELT TENSIONER
Fig. 6: Auxiliary Drive Belt Tensioner Lubrication Points
Courtesy of Volvo Cars of North America.
NOTE: The automatic tensioner for the auxiliary drive belt must be
greased every 30,000 miles (45,000 km) or if an abnormal








 









 




 




 




 




 




 














































































noise is heard from the tensioner.
NOTE: The auxiliary drive belt and automatic tensioner must be
removed from engine in order to properly lubricate.

See page 8 --> http://www.volvoclub.org.uk/tech/ser...ices-Turbo.pdf

 

The good news is that it appears the 182.00 was money well spent for the alternator.
Installed it, started it, found it wasn't charging at all and then remembered I hadn't connected the wires... Doh! Connected it properly, took it for a drive around the block and measured consistent voltage in excess of 14V no matter what was on - Lights, Blower, whatever. Variance in the 2-3 tenths range ... looks good!

Now the bad. I checked the bolt tightness and found one that didn't seem 'right'. It's the top one tying in the top of the tensioner/mounting bracket (with the idler pulley attached at bottom) - the same one that crept out before. (image attached below and on last post). I tightened it ... and tightened it ... and it snapped.
That bolt projects through the mount, through an engine lug, and threads into the back projection of the Power Steering mounting bracket. Fortunately, I can see the threaded end sticking through and I'm hoping that I can pull stuff out of the way and screw it back through the mount and out... (I'm done for the night though so that waits for tomorrow).
I think the reason it didn't tighten properly is because it was the wrong bolt - although I thought I put everything back where it came from - It may be possible that it was in the wrong place when I started or that I just screwed up.

Anyway, kind of bittersweet evening - the operation was a success but the patient ... well, you know.

 

I had the same issue about 2 weeks ago. Turned out to be bad brushes. The tester said it was the regulator. Take the three screws out of the back of the alternator and it's two bolts that hold the whole assembly in, the regulator, diodes, and brushes come out in one big piece. You don't even have to take the alternator out. Just pull and replace it. Took me 30 minutes.