My V70 has an odd issue. My headlights and turn signals will often not work. Always both systems at the same time. Frequently I can put in the key, turn on the accessories, and the lights and turn signals work. When I start the car they do not. Sometimes they work normally. The turning point seems to be when I start the car. Occasionally if they are not working when the car is off, they continue to not work. Sometimes they do. I have only seen the condition change once when the vehicle was running (thank god), and that was to switch from not working to working, about 15 seconds after I tried the lights. Every other time, if they work, they have continued to until I turn off the vehicle to spin the wheel of fortune again.

Any suggestions on where to start? These seem like two parallel systems.

 

Sounds like the ECM (electronic control module) may be acting up. For some reason Volvo decided to put some relays etc inside a sealed box including the low beam activiation. The relays can burn out or the ECM can have connector issues or develop cracks in the solder joints. Start by locating your ECM and checking/cleaning the connectors (there's like 2 or 3 multi-pins that snap in). After that you may want to shop eBay or a yard to find a replacement. What year is the V70? there's a lot of posts on the ECM issues so you can see what other symptoms people have seen. (I had to replace the ECM on my S40 after both headlights went out for a spell...)

 

The lights are a continuous problem for me with my 2000 V70. One of the tail lights doesn't last 3 days after the bulb is replaced. It has to be an electrical issue but my mechanic told me it's not worth fixing. Also the warning lights go on and off even though no problem with the ABS or tracking (for instance) has been detected. Anyone else have these issues?

 

when you say the tail light doesn't last 3 days, are you saying the bulb burns out or that it just fails to light (ie a loose connection)? If you have a multi-meter you may want to check your alternator output voltage - I'm wondering if the voltage regulator is periodically shorting and putting too much voltage out from time to time. If you have a meter, measure the battery voltage with the engine off - it should be in the 12.6V range. Now start the car and measure the voltage with the car at idle. It should be in the 14V to 14.5 range. Does it look consistant of fluctuating higher? Now put some load on the circuits - ie turn the AC blower on high, turn on the rear window defogger, put some AC/DC on the stereo loud enough to scare the neighbors. Measure the voltage - it should stay in the 13-14V range...