That you can bump start it doesn't matter much.

A bad ground, I could go along with. But I'm not totally sure.

Test I would do is: Leave everything hooked up exactly as it is.

Find another car and take a jump start from it. Don't start the other car. In fact, turn it off and disconnect its battery. Run the jumper cables direct from battery to battery.. (positive to positive, negative to negative, of course)

That basically sets your car up to start with a known good battery, but with all the same wiring connections in your car.

Does it start? If so, your connections are probably okay and you might have a bad battery. If it still doesn't start, then I'd be looking at connections.

A tiny bit of research about basic automotive electrical systems (ideally, find a 40 year old book) goes a really long ways to an education. Or if you have a friend that has basic knowledge, have him/her over for a quick run down.

And yes, that box you mention is the regulator. Internal regulators don't appear in Volvos until about 1977, and they have alternators, not generators.

And yes, a simple voltmeter is money well spent, but I've had horrible luck with the super cheap ones at harbor freight. I don't trust them unless I've got a battery with known voltage to check its calibration.

And yes, it could be your charging system is weak, only charging enough to run the car, but not enough to charge the battery fully (especially if you drive with lights on)

Battery is very suspect to me. Do you know what they did to check it? If all they did was check voltage, then they didn't check the battery. Needs to be load tested.

And yes, any connection that's held together with a fastener is suspect (don't forget the battery lug clamp connection to the big wires if the wires are held on with the two-bolt-clamps-the-wire setup. That's a very common issue, often overlooked. Before taking those apart, just buy new ones. You'll probably break them taking them apart.


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-Matt I ♥ my ♂