Low beams both burn out at the same time? - 02 XC70 - Update Topic is solved

Post by **scot850** » 28 Nov 2024, 20:42

The car owner called me to say both low beams burnt out at the same time. I asked him to test the bulbs have actually failed and it is not a fuse.

There is a weird thing with the headlight switch on this car. IT does not actually switch the headlights off or on for that matter. It just seems to have the lights on all the time. Now as we had running lights is that why?

Are the P2 headlight switches know to fail like P80 ones or the relays fail?

Neil.

Post by **abscate** » 29 Nov 2024, 04:01

Canada has been DRL mandatory for some time. I had JRL turn off my DRL in Catherine the 2005 v70 when I bought her , as I hate them, separate rant thread needed.

I would definitely fuse check, and appreciate the light switch isn’t a traditional load bearing switch but a signal to the CEM to turn the lights on

Post by **volvolugnut** » 29 Nov 2024, 07:18

My P2 has not had headlight failure except for low beam burn outs. With Daytime Running Lights (DRL) they do not last very long. I suggest if you have DRL you use only the low brightness low beams which generally have longer life than the extra bright bulbs.
volvolugnut

Post by **Blacklab467** » 29 Nov 2024, 11:32

It’s dependent on the headlight switch position. If it’s not in the most clockwise position the high beams will not stay engaged. The switch must be in this position:

Post by **Blacklab467** » 29 Nov 2024, 12:19

Disregard, I replied to the wrong thread.

Post by **scot850** » 29 Nov 2024, 17:21

It is just strange that both headlights went out together. We have had the same headlight bulbs I think for 10 years in our 06 XC with the xenon lights. I think we had to change a headlight bulb early in ownership (car was 5 years old when purchased from the dealer).

I have replaced all the front bulbs after pulling the bumper off to access the marker light and polish the lights. We have mostly have marker lights go out at the front and a burnt out rear light frame for some reason.

Neil.

Post by **scot850** » 29 Nov 2024, 17:24

Should add, that in trying to find the part number for the headlight switch, it turns out Volvo had 12!, yes 12!! headlight versions for P2's.

That is totally stupid. I could only find 9 as the other 3 are NLA including the version we are looking for.

At least I know what to look for if it is the issue.

Oh, on the DRL point, our DRL I thought only has the side marker/turn lens on. Now I have to go look at our 06..........

Neil

Post by **scot850** » 02 Dec 2024, 21:05

So, thanks to Blacklab247, I now have 2 spare switches to try out. First I tested the bulbs. I have discovered serious butchery on the RH low beam bulb connector. However, the LH bulb works fine when directly powered. I did not want to try tackling the RH one due to time constraints, but I think I managed to confirm continuity on the bulb itself.

We checked the fuses and the headlights are fused separately. Fuses are fine.

Swapped the headlight switch over with the 2 spares and nothing.

Full beams work fine.

Is there a relay somewhere someone can point me to for the headlight low beams?

Thanks,

Neil.

Post by **scot850** » 03 Dec 2024, 23:27

Well today after replacing the other front wheel hub, we decided to see if we can find the headlight relay. Apparently it is not a relay but a 'shunt'.

There is no info as to it's exact location, other than a vague idea it may be under the LHS dash area.

We pulled the cover from the fuse box on the LH end of the dash panel and found another fuse for the low and a second one for the high beams. That fuse was also ok.

Guessing the relay/shunt must be up under the dash panel the owner pulled the lower dash panel off from above the pedals.

He though the might see some relays and took some pictures. I realized they were not the same shape or size I was expecting. What I did notice was that as he was working below the dash, the light could be seen down the side of the fuse box. Rather than try and guess what we were looking for, I grabbed my boroscope which has a built in camera and video. Pushing that down the side of the fuse box we could see the relay panel. With a bit of searching we found the shunts (3 business card sixed flat black push in parts. We managed to remove and confirm the part number was the same as the one the link in this thread:

viewtopic.php?t=105700

Also the part number is the same as that on the other 2 so it is the same size but offset to the other 2 making it look smaller. I confirmed this with Volvo.

We pulled the shunt out and found it also has the 2 side lights on the unit too.

So I have to take a junkyard trip in a couple of days to see if I can find one. A new one is $30 CDN from the dealer and we may invest in a new one if a junkyard one works.

Accessing them looked a major pain, but we discovered that remove the 2 x T25 screws holding the OBD2 connector in place gave a lot more room and better access to the shunts.

I'll update if replacing it or having to resort to Vida and resetting any error code work to get the headlights working again.

Neil.

Post by **scot850** » 05 Dec 2024, 19:23

Well, today I had time to do a run to the junkyard or yards if required. First yard had a handful of P2's of 01-04 years, and most were XC70's.

Once I figured out how easy it was to actually get to the shunts, by removing the LH footwell lower panel (2 x T25 screws and then pull the panel out on the center console end and then peel it out. Then the 2 screws holding the OBD2 connector out (T25 again).

Next take the fuse box cover off, pull the fuse panel out (push tab on top down and then tilt forward from the top).

Finally, not needed but to give a better view, you can remove the light switch by pushing it out from the top from behind the dash by accessing from the fuse box area. This gives a clear view of the shunts.

It was only once I pulled a few (3 in each car are all the same part #), I came on a car that had been in an accident at the front. The broken headlight was on the ground. I decided to pull the wiring harness out of it so I could replace the missing plastic end on the bulb holder.

It was then that the penny dropped. I had been working on the RHF headlight and my young friend the LHF side. Despite me showing him the bulb cover to remove to access the bulb, he actually pulled off the hi-beam bulb cover, hence the different bulb!! So all this may have been for nothing. It may be down to 2 bad bulbs and connectors.

By then I had the spare shunts pulled , a headlight (RHS) stalk from the steering column and another harness cut off from another broken headlight. Oh, well. At least we now have all the main parts unless there is a wiring issue somewhere else!

Neil.