The rear underhood light doesn't work in my 1997 911. It has 12 volts going to the red lead however the brown ground is not grounded - if I insert a bulb and grounded to a nearby screw the bulb work fine, so I'm assuming the brown ground is bad.
Before I get too far into hunting this down, is this a common problem and is there a common area where the rear light ground is known to be bad?
Not too common.
I believe the brown/red striped wire, the ground, is the switched wire that controls this light. I would unplug the little pigtail connector that goes to the switch in the engine hood latch and short out the plug end that attaches to the wiring harness of the car. If the light comes on the latch switch is broken or clogged with dirt or grease. Hose out the switch with a little spray electron/electric motor cleaner and see if it sorts out before purchasing a replacement. The red wire run is a shared common wire to other lamps in the car such as the frunk light.
An easy to sort out issue.
Andy
This was helpful, thank you. I shorted the pigtail and the lamp came on. I'll purchase some contact cleaner and spray into the switch. I don't see a way to remove the switch. I'd prefer to do that. Do you know if the switch pops off? Hidden screw?
Just blow out the entire latch and then regrease it with a light spray grease,
The switch can be taken off but removing a 20-year-old brittle plastic switch may introduce issues you presently don't have. Wait until you know you need a switch and have the replacement in your hand and then contemplate how to remove it.
Andy
The parts catalog shows the switch as part of a complete latch part number. A used latch with the switch is $70 on eBay.
My experience is the little plastic plunger in the switch gets trapped by dried out grease that is applied to the latch, Cleaning up the little plunger by flooding it with spray cleaner and cycling it a few times usually does the trick The alternative is to live w/o the light as it doesn't really illuminate much of anything anyway.
On close investigation, the latch housing looks to be two halves pressed together capturing the switch housing so removing the switch is probably not feasible.
Just some thoughts,
Andy
Success! After dousing the latch/switch from all angles, the light turned on. : )
Now that the latch is pretty much dirt and grease free do I need to be worried about oiling or greasing the latch mechanism? I'm going to guess to switch got gunked up by previous owners spraying different lubricants on the latch. Is lubrication necessary is there a right way to apply it?
Success! After dousing the latch/switch from all angles, the light turned on. : )
Now that the latch is pretty much dirt and grease-free do I need to be worried about oiling or greasing the latch mechanism? I'm going to guess to switch got gunked up by previous owners spraying different lubricants on the latch. Is lubrication necessary is there a right way to apply it?
Get a spray can of white grease and lightly spritz some on the striker part that captures to loop from the lid. A little grease on the switch is OK, it stuck after years of cooking the old grease dry, new grease is probably good to go for many many years before it stiffens up like the old.
