Problem with Detroit speed headlights
Thread Starter
Drifting
Joined: Feb 2017
Posts: 1,462
Likes: 106
From: Cortlandt Manor NY
Problem with Detroit speed headlights
I’m trying everything and can’t find the solution. My Detroit speed headlights only open halfway. There is nothing binding that i can see. When I remove the motors I can open and close the headlights manually easily. I tried removing the springs and also tried using just the inner springs but no help. Anyone else have this problem and found a solution?
thanks!
thanks!
Popular Reply
Jul 8, 2023, 09:16 AM
Safety Car
Joined: Dec 2012
Posts: 3,786
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From: Summerville SC
Funny how the “forum member” who answered the op question is the same one who sells the kits. And he was helping someone who purchased a kit from a competitor. That should tell you all you need to know about who you should do business with. 
richard 454.
richard 454.
Race Director
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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Cruise-In VIII Veteran
Ahh, no.
I thought all C3 Corvette's came with vacuum operated headlight doors.
A large number of people on here who convert to electric doors use a kit offered by a fellow forum member and they all swear by it.
perhaps contact this company and inform them of your issues. Perhaps they can help.
Or, the stock vacuum system is so basic and reliable. Perhaps just put it back, I know, one door opens before the other. But they open.
I thought all C3 Corvette's came with vacuum operated headlight doors.
A large number of people on here who convert to electric doors use a kit offered by a fellow forum member and they all swear by it.
perhaps contact this company and inform them of your issues. Perhaps they can help.
Or, the stock vacuum system is so basic and reliable. Perhaps just put it back, I know, one door opens before the other. But they open.
Le Mans Master
Joined: May 2003
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From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
The module measures resistance to stop the motor.
Sounds like you have tried to reduce that by removing the springs and checked the operation manually.
To determine if its the module- I'd disconnect the arms and see if you get full travel. You can also reset the module by pulling power for 10 seconds.
I have dealt with a couple of them- the module is picky...
Richard
Sounds like you have tried to reduce that by removing the springs and checked the operation manually.
To determine if its the module- I'd disconnect the arms and see if you get full travel. You can also reset the module by pulling power for 10 seconds.
I have dealt with a couple of them- the module is picky...
Richard
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From: Virginia
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Le Mans Master
Joined: Oct 2010
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From: melbourne florida
2023 C3 of the Year Finalist - Modified
I've owned several c3 corvettes since 1975 and have few issues and all were easy to fix. They never open or close at the same time but isn't that a bit fussy?
Race Director
Joined: Nov 2006
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From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
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these vacuum systems are really very simple.
As I said, in the real world I know Many C3 owners. I know one who switched to electric motors. And they have given him grief. I owned 3 C4's over the years. And my convertible got me home from the pub one night with both headlight doors down!
electric headlight doors are not perfect.
Nothing is perfect.
But these vacuum doors are very reliable and very easy to repair if you understand how they work.
And most go electric because one door opens before the other one and they somehow feel that's a problem.
Race Director
Joined: Mar 2017
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From: Virginia
Or you can go out of your way to eliminate every vacuum system, leaving only what is required for engine operation (PCV and vac advance).
You can still have headligts that wink, or rise sequentially. Electricity doesn't have to be scary.
You can still have headligts that wink, or rise sequentially. Electricity doesn't have to be scary.
Safety Car
Joined: Dec 2012
Posts: 3,786
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From: Summerville SC
Funny how the “forum member” who answered the op question is the same one who sells the kits. And he was helping someone who purchased a kit from a competitor. That should tell you all you need to know about who you should do business with. richard 454.
richard 454.
Instructor
Joined: Nov 2019
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Excuse me, I've owned more than one C3. And have VERY many friends with C3's. My 77 had its first headlight door issue about 2 years ago. Put some kits in the actuators and that was it. Cost was so minimal its almost funny.
these vacuum systems are really very simple.
As I said, in the real world I know Many C3 owners. I know one who switched to electric motors. And they have given him grief. I owned 3 C4's over the years. And my convertible got me home from the pub one night with both headlight doors down!
electric headlight doors are not perfect.
Nothing is perfect.
But these vacuum doors are very reliable and very easy to repair if you understand how they work.
And most go electric because one door opens before the other one and they somehow feel that's a problem.
these vacuum systems are really very simple.
As I said, in the real world I know Many C3 owners. I know one who switched to electric motors. And they have given him grief. I owned 3 C4's over the years. And my convertible got me home from the pub one night with both headlight doors down!
electric headlight doors are not perfect.
Nothing is perfect.
But these vacuum doors are very reliable and very easy to repair if you understand how they work.
And most go electric because one door opens before the other one and they somehow feel that's a problem.
I say this as someone whose vacuum lights AND wiper door work just fine...after being fully rebuilt with new vacuum lines everywhere (because, again, it is the most common thing to not work on these cars). I'm not saying this because I couldn't figure it out. I'm a big fan of simplicity, and the vacuum system in these cars is not that. Simple in concept of operation doesn't mean simple. There's a reason the factory put in override valves...
Le Mans Master
Joined: May 2003
Posts: 8,874
Likes: 3,548
From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
Excuse me, I've owned more than one C3. And have VERY many friends with C3's. My 77 had its first headlight door issue about 2 years ago. Put some kits in the actuators and that was it. Cost was so minimal its almost funny.
these vacuum systems are really very simple.
As I said, in the real world I know Many C3 owners. I know one who switched to electric motors. And they have given him grief. I owned 3 C4's over the years. And my convertible got me home from the pub one night with both headlight doors down!
electric headlight doors are not perfect.
Nothing is perfect.
But these vacuum doors are very reliable and very easy to repair if you understand how they work.
And most go electric because one door opens before the other one and they somehow feel that's a problem.
these vacuum systems are really very simple.
As I said, in the real world I know Many C3 owners. I know one who switched to electric motors. And they have given him grief. I owned 3 C4's over the years. And my convertible got me home from the pub one night with both headlight doors down!
electric headlight doors are not perfect.
Nothing is perfect.
But these vacuum doors are very reliable and very easy to repair if you understand how they work.
And most go electric because one door opens before the other one and they somehow feel that's a problem.
The Corvettes that had "pop-up" headlights (C2-C5) -ALL used electric motors EXCEPT for the C3s. GM did this to save money-and such a problem - went back to electric motors on the C4.
The car manufacturer's figured out that vacuum operated windshield wipers were not the ticket in the 50s!!!
Granted nothing is perfect- but not all electric headlights conversions are created equal. There are ones with linear actuators- window motors- and some have used electric motors that were designed almost 40 years ago.
There is even a Chinese copy that copied Mazda Miata headlight motors from 30 years ago!!! Many require cutting wires- splicing- taking apart the dash to connect and even cutting up the headlight assembly! However, I know of one that doesn't...
The other issue is- the replacement junk out there for the vacuum parts. I know several that have thrown good money at the vacuum system - only for the replacement part(s) to add more problems (my favorite below!!!)
So don't just broad stroke- vacuum is great and electric is bad-
Oh- if you do want to go to electric- a simple relay timer with delay- the second headlight will open a second or two later!!!
Richard
Melting Slicks
Joined: Jun 2011
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From: Leland , North Carolina
Race Director
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From: Napa Valley California
I converted my 73 over to electric headlights for the purpose to clean up and eliminate all the vacuum lines in the engine compartment.
My vacuum operated headlights worked fine, but I upgraded to electric.
Like everything in our cars, you can keep the oem parts or change to something different.
Notice I said different, and I didn’t say better.
As long as the headlights operate who cares if they are operated by vacuum or electric.
As far as Richard454’s headlight conversion kits, Richard’s are by far the best quality built conversion kits, and he was one of the first to design and install them into a C3.
Built in the USA!
As far as Richard himself, he has been stepping up and helping forum members for the past two decades.
It doesn’t surprise me one bit that he stepped up and helped a forum member adjust and trouble shoot another vendor’s product.
Richard is one of the best on the forum and it is a shame that we don’t see as much of him as we used to.
Check out his C3 build thread and you’ll find one amazing and beautiful V12 powered C3.
My vacuum operated headlights worked fine, but I upgraded to electric.
Like everything in our cars, you can keep the oem parts or change to something different.
Notice I said different, and I didn’t say better.
As long as the headlights operate who cares if they are operated by vacuum or electric.
As far as Richard454’s headlight conversion kits, Richard’s are by far the best quality built conversion kits, and he was one of the first to design and install them into a C3.
Built in the USA!
As far as Richard himself, he has been stepping up and helping forum members for the past two decades.
It doesn’t surprise me one bit that he stepped up and helped a forum member adjust and trouble shoot another vendor’s product.
Richard is one of the best on the forum and it is a shame that we don’t see as much of him as we used to.
Check out his C3 build thread and you’ll find one amazing and beautiful V12 powered C3.
Instructor
Joined: Nov 2019
Posts: 182
Likes: 112
Nothing wrong with that. As I said, I still have the vacuum operated wiper and headlights, and both work.
So, your headlights failed, and you replaced them. Perfect reliability, except when it failed, but otherwise absolutely perfect! No different than VW owners replacing a failed water pump with a new one every 30k miles...
This is a really stupid hill to die on y'all. You can love something, even if it isn't perfect. In fact, you can love something for its flaws. The vacuum headlights and wiper door are an absurd and brilliantly complex way of operating headlights and wipers. Its fantastic for its absurdity. But it isn't reliable. Never has been, never will be.
New vacuum cans and hoses never failed on any of my C3's.
This is a really stupid hill to die on y'all. You can love something, even if it isn't perfect. In fact, you can love something for its flaws. The vacuum headlights and wiper door are an absurd and brilliantly complex way of operating headlights and wipers. Its fantastic for its absurdity. But it isn't reliable. Never has been, never will be.
Thread Starter
Drifting
Joined: Feb 2017
Posts: 1,462
Likes: 106
From: Cortlandt Manor NY
Thanks everyone for the help. I ended up going through the whole thing again. This time I kept the garage in complete silence while I manually lifted the headlight assembly up and down. You could just barely hear a slight scrapping sound which I tracked down to the headlight shields (aftermarket). They were just ever so slightly brushing against the lower part of the headlight assembly when it went up, right about the half way spot. So I took off both shields and sure enough the headlights work flawlessly, even with the springs installed. So now I am looking for an OEM set of shields to see if they are slightly thinner or maybe I’ll try reworking these or making up something of my own.
Just in case anyone has a problem in the future with these. They are a great kit and work awesome when they are right. The safety mechanism in the motor is just so sensitive that any light resistance will cause them to go into safety mode and stop where they are. When I tell you they were just brushing against those covers I mean just.
Just in case anyone has a problem in the future with these. They are a great kit and work awesome when they are right. The safety mechanism in the motor is just so sensitive that any light resistance will cause them to go into safety mode and stop where they are. When I tell you they were just brushing against those covers I mean just.
Safety Car
Joined: Dec 2012
Posts: 3,786
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From: Summerville SC
Not sure of your year but on my 78 the entire assy can be moved to adjust the gaps around the lid when they are closed. Maybe you can slide it all towards the back slightly so the bezels don’t hit. 