Voltage Overload - No Headlights or Radiator Fan
 

I have a 2002 Volvo S80 T6. I recently jumped my battery using a commercial battery charger. I used the "start/jump" setting, which put out 225 amps. When I started the engine (with the charger still connected), I heard a loud noise coming from my speakers (not the radio, as it was off) and then the noise went away and a Voltage Overload message showed up on the dash. Now, my headlights don't come on at all and neither does my radiator fan. I checked the headlight fuses and they are both intact, but neither side of the fuse causes my test lamp to illuminate. A friend told me that this means the power is cut off before it even gets to the fuses, so something something is blown further up the line. Any ideas?? Could I have blown a relay or a module? Is this an easy fix?? Thanks.

Did you check all the fuses? These cars hide fuses in 3 places - under the hood, in the cabin and in the trunk! It should be one of the big ones for the fan. Lights have their own. A few thoughts - you can try disconnecting the battery for 30 minutes or so to see if you can reset the CPUs and the voltage overload message. I had to do this on my wife's Toyota once for a similar problem. Next is to check/replace the headlight bulbs. (don't overlook the obvious - I had a CEM go on my S40 and it took out both low beam bulbs!). As for the radiator fan, there's also a relay - look under the radiator shroud that say See if you are getting voltage etc. Try turning on the AC to get the fan to kick on...

Thanks for the tips, mt6127. I'll definitely try them and let you know what I discover. I've got my fingers crossed!!

I tried all the fuses and they all work (except the two low beam headlight fuses under the hood). I hear that a blown fuse will illuminate the test lamp when you touch one side of the fuse, but won't illuminate the test light when you touch the other side. When you don't get a response from either side, it's an indication that current is cut off before it even gets to the fuses. The Voltage Overload message stopped coming on once I originally shut the car off and disconnected the professional battery charger. Looking around on the net, I've seen a "module" referenced. Could this be the issue - or a relay? Where are the module and appropriate relay located? How do I test them to know if they're bad/blown? Thanks.