Under Hood Lighting

[mrmojo1111]

Done.

[1991ZR1]

I received the lights today and found out something that people with aftermarket wire harness with switch for the under hood light need to be aware of.

I installed the LED light on the passenger side and it did not work. I removed the LED and tried the other LED on the passenger side with the same result. The stock bulb works.

I installed the LED on the driver side and it worked. I changed to the other LED and it worked also.

Next, I checked the voltage at both light housings and found that the passenger side was opposite polarity from the driver side.

I tried plugging the passenger side light wiring into the stock wire harness and the light works. I will need to switch the terminals in the aftermarket terminal housing to make it work. I guess they didn't worry about polarity when they made the switch harness because it doesn't matter with regular bulbs. It could just as easily have been that both sides wouldn't work or only the driver side wouldn't work.

Scott. It seems that the lense rests against the LED's. Is this ok or should I add a gasket to the lense to add clearance?

[Fully Vetted]

Got mine yesterday. Thanks, Scott. This will be one of my first mods when I get my car back from Corey.

[scottfab]

Originally Posted by 1991ZR1

I received the lights today and found out something that people with aftermarket wire harness with switch for the under hood light need to be aware of.

I installed the LED light on the passenger side and it did not work. I removed the LED and tried the other LED on the passenger side with the same result. The stock bulb works.

I installed the LED on the driver side and it worked. I changed to the other LED and it worked also.

Next, I checked the voltage at both light housings and found that the passenger side was opposite polarity from the driver side.

Curious, I had anticipated this potential and had several C4 lights checked for polarity. They were all neg on the bottom and pos on top.

Originally Posted by 1991ZR1

I tried plugging the passenger side light wiring into the stock wire harness and the light works. I will need to switch the terminals in the aftermarket terminal housing to make it work. I guess they didn't worry about polarity when they made the switch harness because it doesn't matter with regular bulbs. It could just as easily have been that both sides wouldn't work or only the driver side wouldn't work.

This part I'm not quite getting. Was part/all of you harness not stock or just the aftermarket housing???
We're going to need more data from more LEDs assembly users. I took pains to make the assembly such that it could only be installed one way. That may have been a mistake if half of the lamp holders are wired the other way

Originally Posted by 1991ZR1

Scott. It seems that the lense rests against the LED's. Is this ok or should I add a gasket to the lense to add clearance?

The leds should ride snugly on the glass. This should keep them focused on the engine and not blinding people standing beside the engine. Each unit was tested for fit inside my passenger side lamp holder. I'm hoping the holders are all the same size. Having said all that if you are concerned the vibration will "sand" the end of each LED then a washer can be used under the glass. There is another work around but is more involved. Right now there's nothing to make me think there will be an issue.

Thanks for bringing the issues up.

[1991ZR1]

I think the aftermarket harness plugs into the stock harness on the driver side. The light housings for both sides plug into the aftermarket harness. The change in polarity occurred in the aftermarket harness. I don't think anyone with stock wiring will have any trouble.

[HAWAIIZR-1]

Originally Posted by scottfab

Curious, I had anticipated this potential and had several C4 lights checked for polarity. They were all neg on the bottom and pos on top.

This part I'm not quite getting. Was part/all of you harness not stock or just the aftermarket housing???
We're going to need more data from more LEDs assembly users. I took pains to make the assembly such that it could only be installed one way. That may have been a mistake if half of the lamp holders are wired the other way

Hey Scott,

I have the Gordon Killebrew under hood lamp switch as sold by Gordon and Corvette Central. I can't imagine when I installed it years ago that it would cause a polarity issue, but I will let you know as soon as I receive my LED assembly.

Thanks again,

Craig

[PhillipsLT5]

I got my lights today
I have the same problem as 1991 ZR1
Passenger side LED will not work, stock bulb does
Driver side OK
I do have a on/off switch/harness made by?, bought from catalog co.?
A suggested fix to this?

[GOLDCYLON]

Originally Posted by PhillipsLT5

I got my lights today
I have the same problem as 1991 ZR1
Passenger side LED will not work, stock bulb does
Driver side OK
I do have a on/off switch/harness made by?, bought from catalog co.?
A suggested fix to this?

I prob will be in the same boat. Phil.

[scottfab]

Originally Posted by PhillipsLT5

I got my lights today
I have the same problem as 1991 ZR1
Passenger side LED will not work, stock bulb does
Driver side OK
I do have a on/off switch/harness made by?, bought from catalog co.?
A suggested fix to this?

Ok, I've spoken to Gordon Killebrew. Apparently the harness in question is not his. His does not switch polarity. It is the one Mid America sells that is in question.
I found a picture of this harness
Can anyone confirm this is the product?
http://www.mamotorworks.com/corvette...%20switch%20c4
If someone that has this unit and willing to call me I may be able to come up with the least painful option. PM me
I do know the clips that hold the bulb are not swappable since one has the contact tab for the mercury switch.

[tf95ZR1]

Hey Phillip,
Oops, I just saw that you changed the
lighting on/off switch/harness. Can't imagine
how that would change things.



Maybe dumb question, but can you
rotate the LED 180 deg?