1988 volvo 740 sedan non turbo. battery died, it was very old. had it jumped then drove straight to auto parts store and got new battery installed. started right up drove home. parked car . 2 hours later would not start up again. a day later , the only thing that seems to work is the clock. Car does not start. The headlights, windows, radio do not work. with starter does not click when I try to turn over. This has been a good daily driver for 2 years, always started right up.

 

anyone have similar issue? Suggestions? Thanks in advance!

 

Probably a charging issue, that's why the battery died, the new battery got drained not getting recharged. Try jumping it? It should start with a jump but it should die once the jumper cables are removed. Test the alternator with multimeter: as the car is running, put the leads on the battery, red to +, black to - and see what the voltage is. Should be around 14V.

 

Do what lev said, but you probably just need new brushes.

If it dies seconds to minutes after the jumper cables are removed then you know it's 100% alt.

Like I wrote before you probably just need new brushes. If you're any good at soldering it'll cost under 10, if you don't want to mess with it, then you'll need to get a new regulator, usually around $35.

For ebay, enter in your car, type "regulator", hit buy it now, then hit lowest price.

it should show you what equates to a transistor and two pieces of carbon, will look something like this:




It's easy to remove but kind of a PIA to reinstall, it can be done though.

advice, it's much easier to remove the ALT to do all this. that way you can also inspect the slip rings.

 

It really sounds like an alternator/charging circuit problem, but have had similar symptoms with bad earth/battery connections.


It's worth checking the new battery voltage levels (across terminals and positive to engine/bodywork), particularly when nothing seems to be working.


Although not Volvo specific, if fully charged I would expect generically to see something like:


Engine Off: Min 12.5v.


Engine Running: Min 13.5-14.5v


Engine off battery V Levels for indicative charge :


12.68v . . . . . . . . . . 100%
12.45v . . . . . . . . . . 75%
12.24v . . . . . . . . . . 50%
12.06v . . . . . . . . . . 25%
11.89v . . . . . . . . . . 0%


If the voltage is low concentrate on your charging circuit, if good start checking connectors, earth, etc.

 

Thanks everyone! I just a new voltage regulator and Alternator belt, and am about to put them on.

I have no need for AC, and it is not working . can I leave the AC compressor belt off permanently, after putting a new alternator belt on?