I was wondering about the tow indication light in the instrument dash. How is that light illuminated/ activated. I installed a curt hitch and uHaul imported vehicle 4 pin trailer wiring kit. Will I factory or similar trailer wiring harness work this hidden function if there is?

 

Yes, this lamp is activated by the trailer to warn that there is a trailer hooked up and the electrical circuits are working properly or not. This lamp is activated either by the factory fitted electrical loom or a correctly installed aftermarket wiring loom. I am not sure whether all D2's have this trailer lamp as standard or a selected few models.

 

So other than just a indication light of a trailer hookup. Does it affect trans and shifting?

 

Hi, not to the best of my knowledge and I've never noticed any effect on my autobox behaving differently having covered tens of thousands of miles towing heavy loads. I reckon the engine ECU and autobox ECU sense when the truck is going uphill under additional loading and adjust the gearing accordingly.

I believe the trailer light indicates that the system does a self check of the trailer electrics and is there to indicate all is OK and there is a trailer hitched up. You'll note the trailer light flashes when the indicators are used. I believe you also need an HD indicator relay/module fitted when using a trailer. If you have a tow bar fitted it may well have been installed. My trailer electrics and tow bar were all installed when new when I bought the D2 new from the LR main dealer so I cannot be sure about this.

 

Thanks for the information. Does the factory harness support a electric trailer braking?

 

No, you'll need to wire this up yourself.

Additionally, the trailer indicator will only advise of a connected trailer if the trailer is using incandescent bulbs for it's lighting. If the trailer uses LED indicators, then there's a good chance that the indicator will not illuminate, even if all of the connections are working properly.