Try it, two headlights are better than one anytime.
If you are concerned dump the cheapy relays & get some real Bosch, plus keep a spare or two in the rig, no worries.

 

Roler with the exception of the relays I don't see what can fail? Is just some wires and plugs, about as simple as it can get.

 

It's most likely the relays then. But I should be able to upgrade those and make sure the grounds are decent.

 

clear housings and H4s

stock

 

I bought this one from eBay http://www.ebay.com/itm/261461116320...84.m1497.l2649 and I would strongly recommend avoiding it. hooked it all up, ran the high beams for less than 10 minutes. fuse was reading 160 degrees on my laser thermometer with a strong burning smell before I shut everything down. plastic housing around the fuse started melting. I attached some pictures.





melted fuse

REALLY glad I tested it before I was on the road. Last thing I need is no headlights AND a fire under my hood.



if you see these relays, avoid.

 

Did you scrape the grounding points down to shiny metal when installing?

 

Yup. Used my Dremel to grind both ground points to shiny.