My headlamp went out on 2004 XC70 volvo and I found out that it is about $200 to replace it. Then, a guy at Nappa told me that it is probably the transformer. Is there a way to take out the bi-xenon lights and put affordable ones in? Some guy on the internet said that you could switch them out for about $200. Now I can’t find where I read that and am wondering if it is even true???
Funny how this internet works… 
Don’t believe everything you read on the 'net.
HID headlamp reflectors have a different design from regular bulb headlamps. While you could in theory make the switch to regular bulbs, why would you want to. Regular bulbs inserted inside HID headlamp housings offer totally inadequate lighing.
Volvo XC70’s are premium/luxury cars and they demand premium/luxury initial purchase prices, as well as for repair and parts. This general rule applies accross the board, to all premium/luxury makes.
Another way to look at this. You got 6 years out of that headlight, not bad. If Volvo used that light as the DRL also, you ended up with really good life out of the bulb.
If you went through a complete lighting “downgrade” to halogen bulbs with the correct reflector housing and, most likely, adaptations to the computer module that controls the lights, you would be sorely disappointed in the results. The bi-xenons are so much better.
What Bing said.
Now here’s the bad news: You should replace both bulbs at the same time, or they’ll be radically different colors and look stupid.
That said, 6 years is OK, but you can do better with HID bulbs if you give them proper care and feeding. If your car has an automatic headlights function, turn it off, because autolights tend to pop on when you go under wide bridges or in tunnels and garages. The quickest way to wear out an HID bulb is to turn it on and off quickly. That also means stop flashing your headlights at the jerk who just cut you off.
My HIDs(not a Volvo) uses halogens for the brights, but also uses the xenons in conjunction with the halogens. So the result is similar to what my Chevelle did, used 4 lights for the brights. Not sure if Volvo done this in the past or not.
Six years, huh? That’s amazing for a Volvo. Usually any given Volvo part will only last four years (or four hundred miles, whichever comes first), max, if you’re lucky. If you can afford a Volvo, then you should be prepared to pay for expensive repairs. BTW, have them replace both Xenon lamps and ballasts. The other one will probably burn out in a month or two. Volvo owners in general don’t take care of their cars. They just gas 'em up,with the cheapest gas to boot, and go. I’ll bet that at least 75% of all Volvo owners don’t even check their oil.
Some cars do that, some have HID’s for both, and some use only one bulb per side, and an electronic shutter which flips out of the way when you hit the brights.
One lamp of my ?04 XC70 bi-xenon headlamps went out. I brought it to a Volvo dealer and it took them 10 minutes to replace it… THE REPLACEMENT COST ME $1000. They told me that the transformer is part dead and the transformer itself cost $700. I really cannot believe that one bulb cost $1000. I even searched on Volvo repair and found out that the quote is really high?. I cannot understand how is the transformer working for one headlamp yet not working for the other one… can I replace this with aftermarket parts…