So, today I got back after 3 weeks and drove my car again. It drove great the first time I drove it. Later that day, I drove it again for a short distance (less than 10 miles) and it was again fine except the radio kept shutting off then turning back on, But when I got out of the store to drive it home, it starting having real issues.

The radio again shut off, but this time didn't turn back on. Then I noticed the speedometer was freaking out as I came to a stop. It would bounce between 0-20 or 40 or even 60. Same would happen when the car started rolling again, but only the first 1-3 or 4 MPH. Then the speedo would level out. The Tachometer would also sit at 2000 when I would push the clutch in, even though the engine sounded like it was about 750 (pretty normal). The Tacho would also become normal while accelerating. Also noticed that the engine temp gauge was "stuck" at about 8 oclock and the gas gauge was at about 3/4 full despite the tank being full earlier in the day (less than 20 miles before). The fuel and engine temp guages were slowly dropping off as I drove home. Headlights were REALLY weak and the guage cluster lights were non existant. Car was running a little rough and the exhaust smelled very rich when I got home.

Perhaps most telling was that the voltometer was not even registering.

I'm assuming that the car doesn't have much juice left. So where is the most likely problem? Alternator? Battery? Where do I start toubleshooting this problem? Thanks for the help ya'll.

 

First check the battery condition and connections. Go from there. And please provide year, model, etc. Makes it easier to know what we are talking about.

 

Sorry lev, but thanks for the suggestion. didn't even think about the battery connections. 88, 245, Charcoal.

 

i'd start with a voltmeter. if the battery at rest (at least 1/2 hour after being shut off) is much under 12.5V, I'd slap it on a 10-15A automatic battery charger til its fully charged, then let it rest an hour, and it should be 12.8V or something. start the car and it should be about 14V if the alternator is charging the battery.

if not, check the main ground strap, check the big red wire from the battery to the alternator. the alternator charging circuit often doesn't work right if the dashboard light is out or disconnected, so a loose connection in the dash can cause the charging system to fail.

 

Checked the voltage at the battery. It was at 12.2 or something around there. I thought maybe it would start and then I could see if it was charging any better, but the battery was dead enough that it was BARELY turning over, not enough to fire up. Then the battery read 11.8

I'll have to get a charger.

 

This just happened to me on one of my kid's Volvos (1990 760T). Exact same symptoms. Turns out alternator was bad; no charging voltage. I took the alternator into an AutoZone ... they ran the test, it failed, I bought a new one with lifetime warranty for $135, reinstalled and everything was great (after leaving the battery charger on the battery while I was gone getting new alt). After install, meter said battery (car off) was 12.6V and with car running charging voltage was 14.2V. Life is better now for son and his ride.

 

Took alternator to Auto-zone for the test. FAIL!

Never been so happy about a failed alternator. Didn't really want to mess with troubleshooting the electronics on this car. Now if I could just find a good bosch replacement. Would a 90amp bosch alternator work?

 

More amps won't hurt. I think the 90 will, but my experience with volvo alternators has been of the denso type. If it was a denso I could tell you that you could use the 100 amp in place of the 80 amp. I had 100 amp guts rebuilt into mine.

So the best thing to do is do a little investigation into the bosch alternators. I've only ever seen the 80 amp bosch in person.

 

Thanks pooky85. I'm asking because there's a 90 amp bosch not far from me that came off a 940. Just wondering if it would line-up and be compatible with the old 240. How would one research the what bosch alternators are compatible with the 240? I've tried google, but no luck so far.

EDIT: just found out it's a 100amp. p/n 120-465-016 Anyone know if that's compatible with the 240?

 

Dear Fellow Volvo Enthusiasts This spring I have experienced a mired of problems with my Volvo 240 GL a 1992 edition mostly due to the excessive salt used in here in Ottawa on the roads. I cleaned all the grounds and still had voltages problems as well as stating problems. So I cleaned and adjusted everything I could. I also replaced all suspicious tubing. In the process of corrosion inspection I pulled the alternator off. I inspected the alternator for wear and corrosion and decided it was time to replace the unit. Many problems were resolved when the new alternator was installed and the 80 amp Bosch alternator works just fine. However as the working area and fitting the alternator in was very constricted I am glad I got a direct replacement and did not go to some other alternative. Other cleaning and maintenance operations ignition renewal, full and complete cleaning of the air system and adjustments to original specifications. The Volvo is now a true pleasure to dive with the four band new Michelin Hydroedge tires the performance is out standing my suggestion when repairing your Volvo is stay with original designed parts as close as possible. One clue my alternator was going was unstable voltage readings and flickering lights and I discovered a replacement regulator was installed on the alternator so the alternator in my opinion needed to be replaced.

 

well, today the wife had a friend coming into town. So I had to break down and buy an alternator so she could go pick her up. Biked on over to the local car parts store with the alternator in a backpack (those things aren't lightweights). Threw it on and the car is up and driving great. Here's hoping I never have to use the lifetime warranty that comes with the alternator.