I fitted a tow hitch and electrics today to a Peugeot car. As far as I could figure out the single-filament bulbs for the brake lights are also the bulbs for the rear side lights. When the sidelights only are on they have 4V across them; this rises to 12V when the brakes are on. I find this rather an odd idea. Comments anyone?
Bill
Well, it's French, isn't it!
It's far from unusual in these days of multiplexed electronics. Some stuff, especially with LED lights, pulses the power.
Modern car electrics can make use of many electronic tricks. To cut down on expensive high current copper cable.
A 12v filament bulb would be off on 4v, I suspect its 12v PWM. Analogue meter by any chance?
NT
I guess you are right.
Bill
Ah, brilliant idea. Now the police can get you on two offences for every blown bulb.
It could be Can-Bus, or something very similar
I faffed about for an afternoon on a new Merc Spinter Van, trying to obtain a simple GPI from the handbrake switch, nothing made any sense with a multimeter, I then got a scope out, and the full horror of the system became clear !
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