Volvo: Volvo 850GLT HELP!, fuel pressure gauge, electrical problem

Question
Hello. I have a 1997 Volvo 850GLT. My problem is that it keeps cutting out on me. It will start up, cut off while im driving, and then start back up. I checked the battery and nothing is wrong, the battery is fine. The a/c doesn't work anymore but it's fully charged and the interior lights don't work, but the trunk light does. I had a man check the a/c and he said he just jiggled some wires and it started working. Is this an electrical problem? Please help!  

Answer
Susan,
I believe there is an electrical problem possibly the fuel system, pump or relay. Put a fuel pressure gauge on the car and drive until the problem happens and see if it stalls because the pressure goes down. Then see what the cause is for the low pressure. Is the pump turning off (relay or pump) or is the pressure low only (pump begining to fail).
If no problems are found in those areas start looking at the ignition system. Make sure all connections at the coil and cap are in good condition and are tight.
First thing see if there are any fault codes that have been stored in the control unit. That will require a system tester to read the fault codes.