I just picked up a 91' Volvo 240 with 280K miles on it. I'm somewhat familiar with Volvos as I've owned a few in the past. So I drive it from the dealer and let it sit for 6 hours upon purchase. I go to start it and nothing. The battery is new so I'm chalking this up to a slow drain, starter solenoid, or possible voltage regulator.

I jump started it and drove it for 1/2 hour then parked it overnight, same problem. I put a battery charger on it and it says it's fully charged. What are the steps in checking to see where the problem is? I'm going to go put it in neutral to see if it will start, possibly a bad shift lock. After that I will put the multimeter on the battery to see if there's any drainage.

Not in a huge hurring to fix as it's a 3rd car and really just bought it because I love the 240's but any diagnostic info anyone can give on the above would help.

One other note, when I have the battery charger on, there is a loud humming noise coming from around the area of the rear drivers side passenger door and when I pull up on the lock the humming changes. I thought these had vacuum ran door locks? The central locking system does not work either.

It doesn't make sense if the central locking system was draining the battery as when I have the charger on the battery, it reads that it is charged, what gives?

 

I just made a facebook post about this last night. I've seen several situations lately where the battery cables are not properly connected. I would start there is you have not done so already.

 

I pulled fuse #8 to see if the central locking system is causing the no start. I jump started it, drove it around. Will let it set for 5 hours and see what happens. I'll assume if it starts after 5 hours, that is the culprit.

 

Thanks for the reply but after I jump it, drive it for a bit, it will fire back up. It's only when I let it sit for a few hours. I'm really thinking the central locking system (which doesn't work) has something to do with it.

 

Keep on pulling fuses in the same manner untill you get the culprit. Otherwise you can use a multimeter and connect it to the battery when the car is off. Then ask somebody to remove one fuse at a time while you are looking at the multimeter. When you get the culprit you will notice it on the multimeter.

 

I think it is in the wiring at the door jamb that is causing the problem. It starts up fine after pulling fuse #8(let it sit for an hour and it started right up. I found the below information on another site and have ran across this problem in other vehicles with the wiring going bad with the opening and closing of the drivers S.D. I will pull the boot off and see if there are any exposed wires. With 280K miles on the 240, it's no surprise that the insulation might be shot and shorting out, which explains the battery drain and non working system of the CDL.


"This is a very common problem that affects ALL YEAR 240s equipped with the central door locking feature. It's bad wires inside the driver door. The wires going to the key lock switch ("F" in diagram) and also possibly the door lock plunger switch ("A" in diagram). It's usually pretty obvious once you open the door up and look closely at these wires. The insulation on these wires will crumble and fall off, allowing the wires to short. This causes the random/intermittent rapid lock-unlock. And when the car is parked, the locks may be stuck in UP or DOWN mode, which will kill your battery in a few hours. The solution is to cover the bad wires with heat-shrink tubing, tape, etc., or cut them out and replace/solder in new wires. You will probably only have to do this to about 8 inches of wires, but keep an eye out for more than that."

 

when you pull a fuse, put your digital meter in '10 amps' mode (usually have to move the + lead on the DVM to a separate socket for this) across the fuse terminals , you should see 0.00, if zero, then put the meter in the milliamp mode (move the lead back to normal) and do this again, and you should see /any/ residual current leakage on that circuit. anything much over 10 or 20ma is a possible cause for concern. 20mA is 0.02 amps and would take 1000s of hours to drain a car battery which typically has like 60 or 80 amp-hours of capacity.

be SURE to take that meter OUT of any milliamp or amp mode before using it as a volt meter again... an amp-meter is effectively a dead short.

 

That was the Mercedes 240(and 300 and a host of other benzes that had this system) That system sucked when it started going bad

You are off to a great start in narrowing your issue down. Did you see if something was obstructing the door lock button on the drivers side and causing it to get hung up? How about the other doors? Just because the central lock system is controlled by the drivers door does not mean that one of the other doors is not causing mischief since it is a all unlock/lock system. If one of the locks in the other doors is hanging up it would stop the others from working right.

You got a good plan going with the possible damaged wires in the drivers side door, but also go over the 3 other doors and the tail gate if you have a wagon as all have the possibility of damaged wires. If you have a wagon you will be replacing the wires to the tail gate because they happen to get torn up in the hinge

good luck