Electrics: XC70 Headlight Problem

[rw65]

Good afternoon all,
I'm now on my 3rd Volvo, so finally decided to join the club. The car is a 2004 XC70 Japanese import. I have a problem with condensation in the nearside headlight unit. The glass is intact so there is no obvious route for water ingress. My initial thought was to replace the unit, but having been quoted about £800 for the part (#30655903) I am extremely reluctant to go that route.
I haven't been able to find a secondhand unit yet, although I have only been looking for a couple of days. If any members have had a similar issue and found a solution, I would appreciate your comments.
Thanks, Rob.

[Ripmax]

A quick (very temporary) fix is to chuck a few packets of silica gel into the back of the headlight housing. Making sure it's not going to catch on any hot parts, of course.

[Bonefishblues]

Originally Posted by rw65

Good afternoon all,
I'm now on my 3rd Volvo, so finally decided to join the club. The car is a 2004 XC70 Japanese import. I have a problem with condensation in the nearside headlight unit. The glass is intact so there is no obvious route for water ingress. My initial thought was to replace the unit, but having been quoted about £800 for the part (#30655903) I am extremely reluctant to go that route.
I haven't been able to find a secondhand unit yet, although I have only been looking for a couple of days. If any members have had a similar issue and found a solution, I would appreciate your comments.
Thanks, Rob.

Yep.

Remove the unit. Remove all bulbs and available electrics. Fill with water to locate the leak(s) - it'll/they'll likely be between the lens and the housing where they glue together (don brave trousers for that step!). Mark location carefully. Using a good quality clear silicone (I used Loctite), and after very careful drying (hairdryer on cool is good) & cleaning with a suitable solvent, fill the leaky area.

Bask in a job well done

Various guides on YouTube, but that's the essence, and what I have done successfully.

[rw65]

Originally Posted by Bonefishblues

Yep.

Remove the unit. Remove all bulbs and available electrics. Fill with water to locate the leak(s) - it'll/they'll likely be between the lens and the housing where they glue together (don brave trousers for that step!). Mark location carefully. Using a good quality clear silicone (I used Loctite), and after very careful drying (hairdryer on cool is good) & cleaning with a suitable solvent, fill the leaky area.

Bask in a job well done

Various guides on YouTube, but that's the essence, and what I have done successfully.

That sounds like a good solution! Thank you very much for your words of experience, it is appreciated. Best wishes, Rob.

[ASt85]

Originally Posted by Bonefishblues

Yep.

Remove the unit. Remove all bulbs and available electrics. Fill with water to locate the leak(s) - it'll/they'll likely be between the lens and the housing where they glue together (don brave trousers for that step!). Mark location carefully. Using a good quality clear silicone (I used Loctite), and after very careful drying (hairdryer on cool is good) & cleaning with a suitable solvent, fill the leaky area.

Bask in a job well done

Various guides on YouTube, but that's the essence, and what I have done successfully.

Hi Bonefishblues....I must admit you are very brave filling the headlight unit with water - IMHO the coating is so thin that if you use anything other than deionised water you could run the risk of causing damage to the coating.

I opted for an alternative route; I removed the rear black caps and ran the car for a week or so with DRLs on and the caps removed to dry everything out.
I assumed the leak was between the lens and the reflector seal and so coated the whole of the existing seal with a very thin layer of silicone sealant ie I didn't separate the lens from the reflector.

I drilled a 10mm hole just below the centre of each cap, then using cuff sealant (a totally waterproof glue used for dry suit neck and wrist cuffs) glued a piece of Gortex cut from an old anorak across the holes - any water that does get in afterwards is effectively "steamed out" via the "one-way" Gortex, the side that faces the body of the wearer needs to face the inner side of the headlamp unit, so moisture can only go one way ie out of the light unit keeping it dry.

Some models of the V70 have this type of headlamp unit cap factory fitted so you might find a pair on eBay or from a breaker.

[Bonefishblues]

I did my C70 perhaps 9 months ago. Ordinary water. All's still well