Re: Latest mods.... the 90 is coming together nicely
 

I tried LED for lights and concluded that they were not bright enough and optic didn't work with OEM reflectors - light was dispersed.
I installed HID 6000k for fog lights and achieved level of brightness and color to match LED headlights.

Re: Latest mods.... the 90 is coming together nicely
 

This is why I retained my headlight projector HIDs. Even with factory halogens the bulbs were not that bright

Re: Latest mods.... the 90 is coming together nicely
 

I concluded high quality LED by name brand manufacturer designed with proper reflector design, such as GE or Trucklite, is as good as HID headlights. However, Chinese brand LED bulbs designed with no consideration to OEM reflectors look good when looking at the car but don't do much in lighting the road.

Re: Latest mods.... the 90 is coming together nicely
 

Which brand or HID 6000K did you go with - where did you source them?

Re: Latest mods.... the 90 is coming together nicely
 

I went with hidkitlights.com.

https://www.hidkitlights.com/chevrol...FQ5LDQodGncKGA

I have a 94 and bulb is inserted from below for 91 - 95 and bulb orientation is vertical. Note that 90 bulb is inserted from the back and bulb orientation is front to rear. I know it works for 91 to 95. For 90, I don't know. Also, you have a choice of bulb color and ballast wattage choice between 35w and 50w.

Link to my HID fog light post.

http://www.zr1.net/forum/showthread....&highlight=Hid

Re: Latest mods.... the 90 is coming together nicely
 

Thanks SC. That set up looks a lot like the CorvetteMods setup I have installed on my '91. Like GC wrote earlier, operation is intermittent; both fogs tend to flash on when you hit the fog light switch, but then one or the other will drop out. It's as if there isn't enough power available to keep both ballasts operating. I may try an alternator upgrade this winter, but I may try the 881 LEDs option and HID option you went first - it's an R&D project for now.

Re: Latest mods.... the 90 is coming together nicely
 

Concur the kit I used was also from Germany and high quality. But both lights would just fight for dominance. It was annoying so I pulled em.

I wonder if this is more shades of the grounding issue folks have had with the LED headlights on the 90 and 91 as the grounds are different. It may answer the mail on why the fog lights are a problem as well. Also why there seem to be no issues with direct plug and play with C4 models 92-96

Re: Latest mods.... the 90 is coming together nicely
 

I had no idea some we're having issue with HID fog lights until yesterday evening reading earlier posts. I ran my fog lights this morning driving into DC just to check and I did not notice any issue. Mine is a 94. I'll have check the electrical diagram but if headlights and fog lights are on same circuit, could HID head lights or halogen headlights sharing the same circuit with HID fog lights adding up to excessive draw?

Are you guys running 35w or 50w ballasts? Also, was the ground for fog lights isolated from high beam ground?

Re: Latest mods.... the 90 is coming together nicely
 

I was running the 35w ballasts on the fog lights before I yanked em. The headlights are 50w ballasts with the glass projector lenses that Corvettehid.com used to sell. GC

Re: Latest mods.... the 90 is coming together nicely
 

I have the 35W ballasts on the fogs too, but I have Nighthawk LED headlights. I don't have to have the headlights on to have the issue with the fogs (one illuminating, but not both); it happens with just the park lights on too. There may be something to the point made earlier about grounding not being as well done on the 90s and 91s. I am going to order the 881 LED CREE units over the weekend and give them a try. They obviously won't be as bright as the HIDs; if the difference it too much, I may put back the HIDs and look at installing a relay to see if a more direct path to the HID fogs would make a difference.