HID Upgrade for ‘18 Tahoe - Questions

[Hdlf]

want to swap out my halogens for HID. Is the process straight forward via plug in play harness and ballast? Any mods needed on the headlight housing? Debating if I should do it myself or have dealership do it with OEM parts I order.

 

[Doubeleive]

I will just state that if you go with any HID setup that is not OEM that I recommend wiring up relays so the power is not ran thru the factory harness and fuse box, I have ran HID's for practically 2 decades and eventually they will melt a factory fuse box, might not appear for some time but eventually.... just my 2 cents.

 

[Hdlf]

I will just state that if you go with any HID setup that is not OEM that I recommend wiring up relays so the power is not ran thru the factory harness and fuse box, I have ran HID's for practically 2 decades and eventually they will melt a factory fuse box, might not appear for some time but eventually.... just my 2 cents.

Thx much. Will the OEM HID components be a simple plug n play with the halogen or do I need a whole new headlight housing and plug?

 

[Doubeleive]

Thx much. Will the OEM HID components be a simple plug n play with the halogen or do I need a whole new headlight housing and plug?

on the 2018's I don't know, I would look at what you have already and see if there is any factory option for HID already present there may be a different plug sitting there not used I really don't know on the NEW trucks haven't played with any of them as yet, maybe check in your underhood fusebox also and see if there is anything marked HID

 

[Hdlf]

Checked. No extra plugs. I am pretty sure the assembly’s on the ‘18 is similar to the ‘17

 

[Mad Maxx]

No, the Housings, Wiring, and everything is different with OE Halogen VS HID.

It's not a simple plug and play swap for the dealer to do.

 

[cmatt]

I have done this mod (OE HID). It’s expensive, but I have no regrets. Very happy I pulled the trigger.

@mad max is correct. The halogen and HID projectors inside the housing are different. You have to swap the entire headlight assemblies.

For the wiring, you can’t simply plug in the HID housings even though the connector fits. The signal for the low beams is PWM (pulse width modulated) which basically means the voltage is being “pulsed” to the low beam. I actually tried it and the HID bulb kept flickering with the ballast turning off and on because of the PWM signal.

There are two paths you can take with the wiring:

To be completely OE, the BCM needs to be reprogrammed for HIDs. Then there are a few wires to move on the BCM connectors and some wiring to add in the forward lamp harness which will then land in the headlight connectors.

The other method (what I did) is to use a custom relay harness. It will get around the PWM because its pulling power direct from the battery. The original low beam signal only provides the “turn on” signal to the relays.




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[Mark Sartain]

I replaced mine with LED. It was an easy swap, the cut off is perfect and it’s just as bright as my buddy’s factory HID. The color is dead on also, pure white. You will need a shallow model to fit behind the factory cover plug. I bought mine on amazon.

https://www.amazon.com/gp/aw/d/B077BT6M6Z?psc=1&ref=yo_pop_mb_pd_title

https://www.amazon.com/gp/aw/d/B077B7GJ5J?psc=1&ref=yo_pop_mb_pd_title

 

[Marksv]

I have done this mod (OE HID). It’s expensive, but I have no regrets. Very happy I pulled the trigger.

@mad max is correct. The halogen and HID projectors inside the housing are different. You have to swap the entire headlight assemblies.

For the wiring, you can’t simply plug in the HID housings even though the connector fits. The signal for the low beams is PWM (pulse width modulated) which basically means the voltage is being “pulsed” to the low beam. I actually tried it and the HID bulb kept flickering with the ballast turning off and on because of the PWM signal.

There are two paths you can take with the wiring:

To be completely OE, the BCM needs to be reprogrammed for HIDs. Then there are a few wires to move on the BCM connectors and some wiring to add in the forward lamp harness which will then land in the headlight connectors.

The other method (what I did) is to use a custom relay harness. It will get around the PWM because its pulling power direct from the battery. The original low beam signal only provides the “turn on” signal to the relays.

View attachment 323012


Sent from my iPad using TapatalkCan’t

I have done this mod (OE HID). It’s expensive, but I have no regrets. Very happy I pulled the trigger.

@mad max is correct. The halogen and HID projectors inside the housing are different. You have to swap the entire headlight assemblies.

For the wiring, you can’t simply plug in the HID housings even though the connector fits. The signal for the low beams is PWM (pulse width modulated) which basically means the voltage is being “pulsed” to the low beam. I actually tried it and the HID bulb kept flickering with the ballast turning off and on because of the PWM signal.

There are two paths you can take with the wiring:

To be completely OE, the BCM needs to be reprogrammed for HIDs. Then there are a few wires to move on the BCM connectors and some wiring to add in the forward lamp harness which will then land in the headlight connectors.

The other method (what I did) is to use a custom relay harness. It will get around the PWM because its pulling power direct from the battery. The original low beam signal only provides the “turn on” signal to the relays.

View attachment 323012


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Cmatt sent a dm