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Discussion Starter #1
Has anyone installed the IAP headlight upgrade kit? My dumb question: what does one do with the original ground wires in each bucket? This is an add-on type setup that just plugs into the original driver's side headlamp plug while the passenger's side plug goes dormant. I'm sure there is an obvious answer to those who know this stuff, but I'm dumb about car electrics and it's not clarified in the directions that I can see.

By the way, this is a very well-done plug-and-play item for only $40. Here's the link:

IAP Headlight Wiring Upgrade Kit
 

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Page 6, step #15 says to make sure and connect the black ground wire on the new harness in the left headlight under a bucket screw.

As this is apparently the new ground circut for the new wiring and services both headlights, so the old ground wire wouldn't be used or even need to be connected as it's not actually part of the circut anymore if I read the manual correctly.
 

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Discussion Starter #3
OK, in case others are doing this: After a little trial and error the correct arrangement is: old driver's side plug should remain grounded as before, but original passenger side ground should be wrapped off (along with the old plug of course). All of which makes perfect sense when I think about it. Thanks all.
 

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I have the parts to do this upgrade to my 87 Quad, but I intend to ground each bulb seperately and not through the bucket mounting screws.
 

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....I intend to ground each bulb seperately and not through the bucket mounting screws.
Good plan! That ground lug connected to a sheet metal screw into the bucket, and then the bucket just attached to the body by three screws that go into clips is a terrible design.

I splice another 8-10 inches of wire onto the ground lead, run it through the wire access hole in the bucket, crimp on a big ring lug, and attach that to the stud that attaches the horn to its bracket. That bracket is welded to the frame, so it should provide a reliable ground.
 

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Discussion Starter #8
So the bit of new harness and the old ground on the left side get/stay connected?

That seems a bit odd to me, but if thats what makes it go :shrug:
That was my reaction--whatever works! I tried it with both grounds wrapped off and it was just a big goose egg. Keeping both old grounds hooked up, by contrast, just made the passenger-side light angry.

I have a hard time envisioning these circuits I guess, but since the kit jumps off from the old driver's side plug, I guess it makes sense that that ground needs to be there.

Better grounding points are a great idea--quite a rickety setup as stock. In general there's no doubt it's much cleaner to build your own new light circuit with new wiring, relays etc. But with all the other projects I have waiting in the wings I knew I'd never go to the trouble.

I figured this kit is still a big improvement over running all that current through a 33-year-old switch. I only wish some PO hadn't removed the powerblock from my car (no, I have no idea why...); I had to run it off the alternator feed.
 

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Hi,
Guys I called IAP and you use both grounds. the one that comes original one and the one that comes with the kit. I have installed this on my car 2 weeks ago and have upgraded to Halogens. Works great.

Angel
 

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Discussion Starter #10
The old groumds on both sides? Odd, that did not seem to work for me. But it turns out I have a dimness problem on the driver side so I've got to get back in there.
 

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Hi, Dan
Yep that is what IAP told me I think the person I talked to was tom or Tim so you still use both grounds from the old set up and the new grounds from the new set up you also will need to go to the drivers side and attach the two leads that have the fuses in near them to the block that supplies 12 volts to the starter and lights etc. If you just attach it to the front driver side bucket you will not have the correct voltage to supply power to the relays and the new lighting set up
 

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Discussion Starter #13
Hi, Dan
Yep that is what IAP told me I think the person I talked to was tom or Tim so you still use both grounds from the old set up and the new grounds from the new set up you also will need to go to the drivers side and attach the two leads that have the fuses in near them to the block that supplies 12 volts to the starter and lights etc. If you just attach it to the front driver side bucket you will not have the correct voltage to supply power to the relays and the new lighting set up
I used the alternator lug, which I assume should suffice. Have used that spot for headlight relays on another old car I had. For some reason a PO removed the original power block that should sit on the driver's side.

I can't figure out why I got nothing when I was using both old grounds. Will try that again.
 

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Discussion Starter #14
Well, it's always a bad ground isn't it? With one light still dim, I made a jumper to a good solid ground inside the engine bay and bingo--we have light!

I've jerry-rigged something for now but I'm going to take one piece of advice offered here to run some nice tidy grounds to the engine bay on each side and generally get it solid and neat.

Thanks all for the help. The kit is a great product and a cinch to install as long as you don't have underlying ground problems.
 
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