: How do I bench test a 2002 Cadillac Escalade EXT 3rd brake light (off of the truck)?



98cadillac
04-25-13, 05:07 PM
I picked up a 2002 Cadillac Escalade EXT third brake light from an "automotive recycling center" and I want to test it to make sure all of the LEDs light up before I go through the expense of mailing it to someone across the country.

It looks like there are three connectors on the back of it. Can someone tell me which pins/contacts on which connectors I need to connect leads to and which terminals on my car battery I need to connect the other ends of the leads to in order to light up the brake light (without damaging anything, of course)?

I appreciate your help!

the cadillac man
04-25-13, 05:43 PM
I picked up a 2002 Cadillac Escalade EXT third brake light from an "automotive recycling center" and I want to test it to make sure all of the LEDs light up before I go through the expense of mailing it to someone across the country.

It looks like there are three connectors on the back of it. Can someone tell me which pins/contacts on which connectors I need to connect leads to and which terminals on my car battery I need to connect the other ends of the leads to in order to light up the brake light (without damaging anything, of course)?

I appreciate your help!

There should just be two wires but a pic would help(FYI the wires have to be on the right terminal or it could damage the light)
With a pic I can tell by my wiring diagram and let you know which wire is which

98cadillac
04-25-13, 07:14 PM
There should just be two wires but a pic would help(FYI the wires have to be on the right terminal or it could damage the light)
With a pic I can tell by my wiring diagram and let you know which wire is which

Awesome, thanks!

I should have been clearer - there are 3 main connectors that connect to the truck - one big one in the middle, and one smaller one on each end. Each of the smaller ones has 2 wires/2 pins. Let me know if these photos work for you:

107215

107216

107217

107218

107219

107220

107221

the cadillac man
04-25-13, 07:27 PM
Awesome, thanks!

I should have been clearer - there are 3 main connectors that connect to the truck - one big one in the middle, and one smaller one on each end. Each of the smaller ones has 2 wires/2 pins. Let me know if these photos work for you:

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107215"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107216"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107217"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107218"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107219"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107220"/>

<img src="http://www.cadillacforums.com/forums/attachment.php?attachmentid=107221"/>

Ok that's great as soon as I get back home I will look at the diagrams for it

98cadillac
04-25-13, 07:28 PM
Ok that's great as soon as I get back home I will look at the diagrams for it

Thanks! That's why I love this forum!

Logandiagnostic
04-25-13, 10:02 PM
The last picture shows a red plug with a blue retainer. Unplug that connector and the 2 wires (red and black)...are for the third lamp.

98cadillac
04-25-13, 10:43 PM
The last picture shows a red plug with a blue retainer. Unplug that connector and the 2 wires (red and black)...are for the third lamp.

Thank you. I have a pair of red and black wires with small alligator clips on both ends. Would I just attach the alligator clips to the pins of the corresponding color after I unplug that connector, then attach the alligator clips on the other end of my wires to the battery terminals of the corresponding color?

the cadillac man
04-25-13, 11:07 PM
Thank you. I have a pair of red and black wires with small alligator clips on both ends. Would I just attach the alligator clips to the pins of the corresponding color after I unplug that connector, then attach the alligator clips on the other end of my wires to the battery terminals of the corresponding color?

The larger harness with five wires I think goes for the rear brake and taillights
The other is red being hot as the blue wire is hot from the trucks wiring

98cadillac
04-26-13, 01:04 PM
Thank you everyone for the replies.

Can someone confirm the steps for me - are they what I thought they were with my alligator clips above? I would think it is as simple as connecting the hot and ground wires to the corresponding battery terminals, but these units are hard to find used so I want to be sure I understand the instructions and know what I'm doing before I do it.

Thank you!

the cadillac man
04-26-13, 05:51 PM
Thank you everyone for the replies.

Can someone confirm the steps for me - are they what I thought they were with my alligator clips above? I would think it is as simple as connecting the hot and ground wires to the corresponding battery terminals, but these units are hard to find used so I want to be sure I understand the instructions and know what I'm doing before I do it.

Thank you!

As along as the positive is on the red and negative is on the black you will be good(tip use a fuse in line on the positive side to be safe)

98cadillac
04-26-13, 07:45 PM
As along as the positive is on the red and negative is on the black you will be good(tip use a fuse in line on the positive side to be safe)

Thank you. I have a bunch of spare fuses; do you know what amp rating it should be?

the cadillac man
04-26-13, 08:09 PM
Thank you. I have a bunch of spare fuses; do you know what amp rating it should be?

10 amp its the same as in the truck so no damage will get done to the light

98cadillac
04-26-13, 08:14 PM
10 amp its the same as in the truck so no damage will get done to the light

Thanks!

the cadillac man
04-26-13, 09:14 PM
Thanks!

Your welcome I am glad to help

98cadillac
04-26-13, 11:16 PM
I tested it at the plug pointed out by Logandiagnostic above and thankfully, it worked.

Since it was a plug rather than a socket, there were no pins to clip to, so I rigged up the contraption in the photos below. Thankfully I have auxiliary positive and negative connections under the hood, since my battery is under the back seat.

If I had an inline fuse holder in my workshop, that would have been handy, but this ended up working:

107248

107249

107250

107251

The plug in the photos is an old one from something else that I ended up replacing, not the plug from the 3rd brake light of course. I included it in the pictures as an example.

N*Caddy
04-26-13, 11:43 PM
Yeah that is the correct procedure to test the light.
A fuse is always a good idea good job!

The red wire is positive terminal and the black wire is the negative (GND) terminal.
For the LEDs the polarity is important (LED = Light Emitting Diode) so basically an LED is a diode. And just like a diode it will conduct electricity one way and will be very high resistance (we can approximate it as infinite) the other way. There will be no damages to the LEDs if the polarity is reversed so you can test with confidence if one way doesn't work then just swap the wires (change the polarity) and it will lit.

the cadillac man
04-27-13, 12:00 AM
Yeah that is the correct procedure to test the light.
A fuse is always a good idea good job!

The red wire is positive terminal and the black wire is the negative (GND) terminal.
For the LEDs the polarity is important (LED = Light Emitting Diode) so basically an LED is a diode. And just like a diode it will conduct electricity one way and will be very high resistance (we can approximate it as infinite) the other way. There will be no damages to the LEDs if the polarity is reversed so you can test with confidence if one way doesn't work then just swap the wires (change the polarity) and it will lit.

Some LEDs can be damaged by reverse polarity hence why I said not to reverse the connections I didn't know it wouldn't harm these

98cadillac
04-27-13, 02:08 AM
Yeah that is the correct procedure to test the light.
A fuse is always a good idea good job!

The red wire is positive terminal and the black wire is the negative (GND) terminal.
For the LEDs the polarity is important (LED = Light Emitting Diode) so basically an LED is a diode. And just like a diode it will conduct electricity one way and will be very high resistance (we can approximate it as infinite) the other way. There will be no damages to the LEDs if the polarity is reversed so you can test with confidence if one way doesn't work then just swap the wires (change the polarity) and it will lit.

Thank you for the reply and the details. The fuse was the cadillac man's idea, so thanks to him for that.

the cadillac man
04-27-13, 02:32 AM
Thank you for the reply and the details. The fuse was the cadillac man's idea, so thanks to him for that.

It's better to be safe then sorry(I learned that when installing my audio gear in my car(long process)