Why are there two fittings for taillights etc?

[ShampooEfficient]

Slightly frustratingly, the online bulbs guide for my car listed the rears to be straight pin, rather than offset, and so it's those that I've bought for the indicators.*

For one thing, it's a bloody idiotic bit of design by Nissan, that the taillight bulbs are straight-pin, but the indicators are offset-pin... but why are there two different fittings in the first place? Surely it's something that would make sense to be standardised, since they already have to be Xmm diameter, Y watts in power, etc, etc...

• yes, I should have checked myself, but I've always trusted the guide before with no problems...

[maxi1990]

Because for some strange reason car manufacturers love to make there cars with as many different size nuts, bolts, screws and clips they can get there hands on. Worked for ford as a body repairer and it seems to be an excellent way to make jobs take a lot longer unfortunately.

[Dave Brand]

ShampooEfficient said:

For one thing, it's a bloody idiotic bit of design by Nissan, that the taillight bulbs are straight-pin, but the indicators are offset-pin... but why are there two different fittings in the first place?

Tail lights will be 5W, indicators will be 21W, so using different fittings prevents the wrong bulbs being used. If twin-filament bulbs are used the offset pins ensure that the bulb is inserted with the filaments the right way round.

[ShampooEfficient]

Dave Brand said:

ShampooEfficient said:

For one thing, it's a bloody idiotic bit of design by Nissan, that the taillight bulbs are straight-pin, but the indicators are offset-pin... but why are there two different fittings in the first place?

Tail lights will be 5W, indicators will be 21W, so using different fittings prevents the wrong bulbs being used. If twin-filament bulbs are used the offset pins ensure that the bulb is inserted with the filaments the right way round.

That would make sense, but for the fact it's got twin-filament stop/tail bulbs, with straight pins...

[TallPaul]

Do you mean the 21W indicator bulb has either straight or offset pins? A few manufacturers specified offset 21W indicator bulbs as they were amber, for fitting into indicators with clear lenses.

[ShampooEfficient]

TallPaul said:

Do you mean the 21W indicator bulb has either straight or offset pins? A few manufacturers specified offset 21W indicator bulbs as they were amber, for fitting into indicators with clear lenses.

That could well be it. Still daft though. As if someone might go "ooh, clear bulb, that'll be lovely in my indicator".

[GuinnessMK]

My wife got stopped by the police once while driving my company car.

"Do you know you have your fog lights on madam?"

"Erm, no I don't"

"Yes you do"

They have a look at the back of the car, she presses the fog light button and they light up. Copper looks confused. Turns out the mechanics at my local VW dealer had made a square peg fit the round hole and manage to fit brake light bulbs into the tail light holders, but in such a way that it looked like the brakes were on all the time.