View Full Version : Parking Lights and Melted Headlight Switches

07-07-2013, 11:18 AM
The rear parking light bulbs will hold a 1156 bulb. Just for fun, I put a white LED module in one of mine to see what would happen.


(Please ignore my dead brake light... it works if I wiggle it.)

Now this got me thinking about the fact that the socket for these bulbs is the same. According to the Owner's Manual, the parking light bulbs back there are 5-watt bulbs, and the brake light bulbs are 21-watt bulbs. That's a pretty big difference. I wonder how many people, in the dark days before the Internet made such information widely available, ended up melting their headlight switch, because they bought their DeLorean without the Owner's Manual, and put 1156 bulbs in the parking light sockets.

Greasy DeLorean Mechanic
07-07-2013, 01:33 PM
I suspect the lower wattage bulb spec was so that tail lights wouldn't be same lumens as the brake lights.

42 watts at 13.5 volts is only 3 amps -- surely even the British can make a switch capable of handling that.

Or can they?

Bill Robertson

07-07-2013, 03:22 PM
I wouldn't lump Lucas in with the rest of the Brits -- after all, even Lucas is the butt of many a joke in the UK.

But considering Lucas' propensity for under-engineering things, I wouldn't put it past them... vintage Lotus owners have to deal with flaky-to-useless Fan Fail Modules, and MG and Jaguar owners have plenty of reasons to hurl oaths in Lucas' direction!

Those wires back there behind the headlight switch are pretty darned thin. I think the parking light circuit, along with the starting circuit, suffered from bad math (amps/wire size calculation). When I replaced the wires in the starting circuit with the next size up, all my starting problems vanished. But that's another story...

Anyway, it's just a thought I had. And we'll never know for sure... I'm just thinking aloud.

Greasy DeLorean Mechanic
07-07-2013, 03:58 PM
If you wanted reliable you should have bought a vintage Ford.

I have never heard a single old F-150 driver complain about his or her headlight switch.

Bill Robertson