Tail Light Lenses Melt - 940 Wagon

I am wondering if you are using over-wattage bulbs in there. It shouldn't happen.

RS

A bad contact between the bulb-holder and the lamp housing might cause enough heat for the plastic around the contacts to melt. This might be more likely in cheaper aftermarket housings than in original higher quality Volvo parts. If the red coloration is being burned off it must only be on the surface of the lens, rather than right through the plastic. Possibly the additional heat from the bad contact, or gases from the melting/burning plastic, are destroying the coating.

My '94 940 wagon has an intermittent bad contact problem but it's only on a brake light so it wouldn't generate as much heat as it would if it was on a tail light.

You might be better off buying used original parts from a breaker, or off eBay, than repeatedly spending money on cheap aftermarket new parts.

Certain aftermarket taillights for the 200 and 700/900 wagons seem to be made of plastic that's not heat resistant enough. Maybe if you mounted a 12 volt computer fan to air cool them.... ;)

Wouldn't that trip the bulb failure light?

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

void _-void-_ in the obvious place

I don't know what point the bulb failure light starts tripping. After cleaning up the contacts the bulb failure light stays off for about a month but I don't know if the contact is as good as it should be and I don't know whether or not the contacts are getting hot. Eventually the bulb failure light starts coming on intermittently and, now, I know it's time to do another clean-up.

At first I had a lot of trouble diagnosing the problem because the bulb failure light would only come on while the car was moving. If I parked up to take a look at what was happening everything worked ok! Finally the contact became poor enough for the bulb failure light to come on while the car was standing still.

While trying to figure out the problem I was followed by more cops than in the previous 28 years of driving (or it just felt that way). :)

It's worth looking, though my experience has been that taillights are almost always either the first thing to go at wrecking yards or they're in bad shape. A higher class more expensive yard might have better stuff of that sort though.

Check the reversing light lenses carefully. As posted in another recent thread the solvent welds do sometimes fail.