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Less is Better
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Discussion Starter #1 (Edited)
This is a long one...

I've had quite a journey to fix a dead headlight and I'm not even done yet. I figured I'd share. I rarely drive the car when it's dark enough to need the headlights but I went out for a dusk drive last week. I noticed when I got home that my left low beam wasn't on. All other lights were great.

First thing to do is to check the fuses. On the Elise low and high beams, left and right, each have their own fuse. I checked the fuse in the box under the right access panel, everything looked good on inspection and with an ohmmeter.

Next step -> light bulbs. I bought a set of H1s on Amazon that are supposedly a little brighter than "stock" (how do they know how bright my stock bulbs are?) but have the same power rating. I decided for the very rare occasions that I use the car with the lights on, I will avoid the brain damage of trying to fit LEDs.

My car has a newer set of headlight lenses. The originals lost their clear coat when the clear bra was removed and when I had them re-clear coated, the painter ruined them. What I learned from the following description is that every headlight lens on an Elise fits the car differently. Why Lotus, why??? The original set of lenses fit against the body perfectly. The gaskets sat tight against the body and everything lined up perfectly. The replacements, not so much. The first new set I received were incorrectly glued together. That's right, the factory glued the lens to the bucket so far off that you could see the black plastic of the bucket creeping out from the side of the lens. Who let's that kind of thing leave the factory? The replacement set to those sits just a bit too high on the body so that the line along the fender ridge from the lens to the body is slightly disjointed. They also have a little gap between the edge of the lens and the body along the outside edge of the car on both sides. Like the lenses have more curve than the body of the car. It wouldn't even be noticeable by anyone else as the gasket mostly hides it, but to the owner, it screams at me. The gaskets are a total pain to get in place and have them stay in the right place when fitting to the car.

The reason I wrote the last paragraph is to express my anxiety every time I open the lights up because I'm going to have to deal with alignment issues again. But I did it anyway. Replaced the left bulb, turned the lights on and...nothing. Problem not solved. On to checking relays.

I suppose looking back I should have checked the old bulb before assuming that was the problem, but the new ones are brighter, so I went ahead and replaced the right one as well. Of course, while trying to get the right lense seated, I heard a pop, pulled it back off and found that the post at the top of the lens that holds the metal nut is about 25% pulled free of the lens. Lotus holds this post to the lens, which is under pretty significant tension, with 5 heat stakes and some kind of rubber glue that I bet is just RTV. Man, this car is British. So the lens is sitting on my workbench right now with gobs of JB weld drying on it to hold it in place for the next round. I have to keep telling myself that I will not crank on this bolt when I put it back in.

Step 3, the relay box. For anyone who doesn't know, the car's lights are driven through relays that sit in a box behind the gauge cluster. There are 7 relays in total in that box. I removed the cowling and the gauge cluster to get to the box. Every time you take off the cowling, one the the little metal clips that holds it on WILL pop off and get lost in the bowels of the dashboard. This time I got lucky and only one popped off and I found it. One of the connectors on the back of the gauge cluster is REALLY tight.

You can buy a replacement box for about $150 or there's a company called Atlanta Speedometer that sells a set of replacement relays for the DIYer for $50. So I figured I'd try my hand at desoldering and extend the repair project. The relay that drives the headlights was reading a bit low in resistance but so was another one, so I figured I'd replace them all.

If you've ever tried desoldering, it's kind of fun. You heat the solder joint up and pull the molten solder out with a little reverse syringe. But it doesn't always pull out all the solder and sometimes a pin is still stuck to a barrel. In which case, I ended up pulling on the relay until the pin broke off and then desoldering the pin. Eventually I got all the relays off and soldered the new ones in. Everything looked good. I reconnected everything, hit the parking light button and...no parking lights. I hit the headlight button and both low beams come on. Blinkers also still work. Only the right high beam comes on. So I fixed one problem and then proceeded to cause another. At least I know it was originally the relay. I suspected that I damaged the board while removing the old relays and when I looked under magnification, yessuree, there's a crack in the board across a few traces. Oh well, so much for finesse.

As it sits now, I have the replacement relay box on order. SJSportscars in the UK has them in stock so it will probably be about a week. And I have a headlight lens sitting on the workbench waiting for epoxy to dry. I also opened up the holes in the lens mounting locations to hopefully give me some more freedom of motion in the fitting of the lens. Maybe I'll be able to get the top surface to come down a little lower and line up with the fender. Hopefully in a week I'll be able to update the thread with a success story.
 

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I feel your pain! I do wish there was a viable solution to the poor lighting. Inokinetic had a plug & play HID upgrade that's currently sold-out. Not sure of its real world reviews...? Mine haven't broke yet, but GRP offers this Headlight Housing Tab Repair Kit when the time comes:

 

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Less is Better
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Discussion Starter #3
I feel your pain! I do wish there was a viable solution to the poor lighting. Inokinetic had a plug & play HID upgrade that's currently sold-out. Not sure of its real world reviews...? Mine haven't broke yet, but GRP offers this Headlight Housing Tab Repair Kit when the time comes:

Yeah, the bulbs aren't great and I've had good luck with LEDs on other cars but there's just no space for the fans of an LED bulb on this car without cutting out the clam.

The kit wouldn't have helped for my problem, unfortunately. The support separated from the base of the lens housing instead of at the clip nut end. I think the JB Weld did a pretty good job of holding the post down so I'm going to call that part done for now. Now I'm just waiting for my replacement switch pack to make it from the UK. It looks like it's a couple more days away.
 

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In a past life I made my living desoldering components on pc boards[for CAT scans among other things]
a few tips:
HAving a good soldering iron is a start. If it can do plumbing, it cannot do PC boards. Clean the tip and get it coated with electronics solder to get good heat transfer. Good old leaad solder works better. I have breathed in plenty of solder fumes and it hasn't hurt me nuu-u-u-u-u-nnnnnn[twtich]
Add solder first. Not intuitive, but it adds fresh flux and makes the solder flow better
rest the iron on the lead, not the pad, you are removing the component, you would rather overheat it than the board.
Solderwick is good for very heavy leads, but tends to lift pads on smaller things. A 'solder sucker' is the tool.Or one of those tiny turkey basters
After you have removed the solder from the lead and pad, using the tip of the iron, push the lead around to break the last little grip of the solder

If you do wreck an etch, no problem, while we used 26 wire wrap wire to repair broken etches, a single strand from a say, 18 ga stranded wire will do for signal traces, larger for power traces. If it spans more than 1/2 inch super glue it to the surface. The etches are always smaller than the wires going to them, I guess they can lose their heat to the board

Don't worry, you haven't seen stress till you pull the feedthrough out of a 5 layer board......
 

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Less is Better
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2,678 Posts
Discussion Starter #5
In a past life I made my living desoldering components on pc boards[for CAT scans among other things]
a few tips:
HAving a good soldering iron is a start. If it can do plumbing, it cannot do PC boards. Clean the tip and get it coated with electronics solder to get good heat transfer. Good old leaad solder works better. I have breathed in plenty of solder fumes and it hasn't hurt me nuu-u-u-u-u-nnnnnn[twtich]
Add solder first. Not intuitive, but it adds fresh flux and makes the solder flow better
rest the iron on the lead, not the pad, you are removing the component, you would rather overheat it than the board.
Solderwick is good for very heavy leads, but tends to lift pads on smaller things. A 'solder sucker' is the tool.Or one of those tiny turkey basters
After you have removed the solder from the lead and pad, using the tip of the iron, push the lead around to break the last little grip of the solder

If you do wreck an etch, no problem, while we used 26 wire wrap wire to repair broken etches, a single strand from a say, 18 ga stranded wire will do for signal traces, larger for power traces. If it spans more than 1/2 inch super glue it to the surface. The etches are always smaller than the wires going to them, I guess they can lose their heat to the board

Don't worry, you haven't seen stress till you pull the feedthrough out of a 5 layer board......
All sound advice. I've been in the electronics industry for 20 years so I should have known better, but the one thing you didn't list is patience :).

I actually think I did a good job of removing the solder in general, but when I found that a couple pins were still soldered to the barrels, I decided to force it instead of run it through a couple more heat cycles. I'm attaching a couple of pictures of the bare board.

1266659


1266660


Repairing traces with external wires is typically referred to as "blue wire" by the EEs around here. I considered doing that repair on this board, but the crack could be extensive and I worry about finding the right path for all of the pins without a real board layout file. So I tried, I failed, I'll just replace it.
 

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Lot more going on in that little thing than one would have thought. What can it be doing other than proving out mean time between failures for various components?
 

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Less is Better
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Discussion Starter #7
Lot more going on in that little thing than one would have thought. What can it be doing other than proving out mean time between failures for various components?
Yeah. It's got some small ICs, a couple big caps and a bunch of little caps and fuses. All with a thin conformal coating. I suspect some of the extra electronics controls what combination of lights can be on when and perhaps controls the fast blink if there's a bulb out?
 

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Less is Better
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Discussion Starter #8
The saga finally ends...

I got my new relay box from SJ Sportscars. Great to deal with, BTW. And I finally have my headlight back!
 

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Less is Better
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Discussion Starter #9
I made some videos to detail headlight troubleshooting and repair

Part 1:

 
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