Headlights flicker when high beams are on
 

Just noticed the headlights on my 2000 XJ are all of a sudden flashing hi, lo, on and off while high beams are on. Dont think its the alternator, cause dash lights, radio and everything else electrical seems to be fine. Can it be as simple as headlights are going or a fuse needs replacing? It's pretty scary driving on country roads at night where theres no lights, just deer waiting to be hit.

Here's something to help with that.CRUISER'S MOSTLY RENIX TIPS

HEADLIGHT HARNESS UPGRADE

NOVEMBER 17, 2015 SALAD 48 COMMENTS EDIThttps://i0.wp.com/cruiser54.com/wp-c...size=300%2C225
https://i0.wp.com/cruiser54.com/wp-c...size=300%2C265


It’s easy to install a supplemental headlight harness.

From the factory, the voltage to the headlight bulbs travels from the battery, through connectors, inside the cabin, to the headlamp switch, and then back out to the lamps via undersized wire and more connectors. It’s not uncommon to find only 10.5 volts at the lamps.

The supplemental harness is installed so that it provides battery voltage to the lamps and is just triggered by the factory wiring. The result is about 35% brighter headlamps and headlight switches that don’t melt and burn out.

Here’s a link to a harness on ebay: http://www.ebay.com/itm/CERAMIC-H4-H...-/330997592807

Absolutely plug and play:

• Remove grille and headlamp bulbs. I fed my harnesses from the passenger side starting between the battery and the back of the headlamp housing, over to the driver side.
• Plug the driver side bulb into the new harness.
• Attach the new harness’s ground wire under one of the small bolts on the radiator support after scraping the paint off under it.
• Attach the harness to the existing harness behind the grille working toward the passenger side.
• Plug the new harness plug into passenger headlamp.
• Plug original headlamp plug into receptacle on new harness.
• Attach the ground for the passenger side just like you did the driver side under a radiator support bolt.
• Attach relays with provided bracket on the passenger side inner fender.
• Connect power wires to battery.

I bought the harness that Cruiser54 linked to and it has been a big improvement.
Brighter lights. Less current going through the headlamp switch. All modern cars
use a similar relay setup. This brings the XJ up to date.

It takes less than an hour to install. For peace of mind, get a couple of replacement
relays from the local auto store and put them in the glove box.