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1978 Blinker problem

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Old Jul 11, 2022 | 05:03 PM
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Default 1978 Blinker problem

So i have a blinker problem..


You can see, the yellow marking lights works ok when blinking. They blink, go out and blink
The front daytime running lights blink, dim, and blink. My MOT guy demands they go fully
out when blinking. Apparently, it's the law here en Denmark. I told him, that's
how they work fom the factory. But he doesn't care.

A guy told me to get a new flasher relay. Is this the correct way? Which flasher relay should i get?
i suppose it's not a standard one since it has to change the amp's i guess? i would like it to blink a bit slower as well.

Or should i rewire the wiring, so the orange marking lights connects to the Daytime
running lights? won't that make the lighting very dim?

This weekend i redid the whole lighting harness and the fuse box received an overhaul. it looked nasty, so everything is in great condition at the wire harness.
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Old Jul 11, 2022 | 06:48 PM
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You can see what I did for my 80 here, including DRLs, and special flashers to make everything work with LEDs

Not exactly what the MOT wants, but the wiring diagrams might help.

https://www.corvetteforum.com/forums...s-learned.html
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Old Jul 11, 2022 | 07:39 PM
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Get an electronic flasher. Leds make the old style flashers blink fast like that.
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Old Jul 11, 2022 | 08:30 PM
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As you can see in my video, my side marker lights, and front turn signal lights, alternate (as yours do), and completely turn on and off (as yours need to).

It was not a small amount of effort to make them do this (with working DRLs, which will work even better in your car with clear lenses). The details, and the parts needed, are in the thread. A new LED-capable 3-wire flasher might be sufficient to get started.

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Old Jul 12, 2022 | 07:27 AM
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When your headlights are on BOTH front parking lights and side marker lights should also be on through circuit #9.
It is not clear to me that BOTH are on as the video starts when the right turn signal is already flashing.
When you move over to the left side of the car the front left parking light is definitely OUT before you select the left side.
Headlight Switch ON Circuit #9 will power one side of both front #1157 Bulbs.
L or R turn selected either Circuit #14 or #15 powers the other filament of the front 1157 bulb(s)
If any of the bulbs are defective in the L or R circuit it can affect how each circuit(s) work.
This photo is from the 1978 Corvette Electrical Troubleshooting Manual with circuit operation included.
I omitted the Brake Light portion of the circuit operation text...
I would say other than a possible faulty front left 1157 bulb it looks like the circuit is working as designed.

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Old Jul 12, 2022 | 07:59 AM
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Would your MOT care if the only time the front parking lights are ON is when they are flashing?
To do that Circuit #9 could be removed (Brown Wire) from the turn signal extension harness connector.
You would still have side marker lights through Circuit #9.
You would NOT have front lights when the headlight switch is pulled.


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Old Jul 12, 2022 | 10:30 AM
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Originally Posted by bruiser
Get an electronic flasher. Leds make the old style flashers blink fast like that.
Can you provide me with a link to which flasher i should buy? i do not have LED bulbs mounted.

Last edited by Simonp3; Jul 12, 2022 at 10:38 AM.
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Old Jul 12, 2022 | 10:31 AM
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Originally Posted by bmotojoe
Would your MOT care if the only time the front parking lights are ON is when they are flashing?
To do that Circuit #9 could be removed (Brown Wire) from the turn signal extension harness connector.
You would still have side marker lights through Circuit #9.
You would NOT have front lights when the headlight switch is pulled.
No i need to have daytime running lights as well.
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Old Jul 12, 2022 | 10:57 AM
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Originally Posted by Simonp3
Can you provide me with a link to which flasher i should buy? i do not have LED bulbs mounted.
https://www.superbrightleds.com/more...asher/779/833/
Electronic LED Flasher Relays have no minimum load-12VDC. Eliminates the need for load resistors, turn signals will flash at normal rate with or without LED bulbs. Use the Flasher Selection Guide to determine the correct Flasher Relay for your vehicle.

You can usually get these at any auto parts store.

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Old Jul 12, 2022 | 01:37 PM
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Problem is you can install what ever flasher relay you want, it will not cancel out Circuit #9.
Circuit #9 is a direct feed from the headlight switch and will illuminate one side of the 1157 duel filament bulb anytime the headlight switch is in the first or second position.


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Old Jul 13, 2022 | 02:52 AM
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When I moved to Australia I had a similar issue with changing lighting. As stated above you have a twin element bulb up front.
My situation was in Australia you can not have a amber running light. it has to be clear.
My solution was to add an extra socket to the back side of the housing. if you look you will see that the original socket is off to one side. so I installed a second socket that now runs a white or clear LED bulb in it. and the amber bulb is just a turn signal bulb. in the beginning I had an issue with the clear bulb shining light through the amber bulb. I solved this issue by running a amber bulb with a small globe head. I'll try to get a couple photos shortly.
This should solve your problem however.
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Old Jul 13, 2022 | 03:03 AM
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Originally Posted by 4-vettes
When I moved to Australia I had a similar issue with changing lighting. As stated above you have a twin element bulb up front.
My situation was in Australia you can not have a amber running light. it has to be clear.
My solution was to add an extra socket to the back side of the housing. if you look you will see that the original socket is off to one side. so I installed a second socket that now runs a white or clear LED bulb in it. and the amber bulb is just a turn signal bulb. in the beginning I had an issue with the clear bulb shining light through the amber bulb. I solved this issue by running a amber bulb with a small globe head. I'll try to get a couple photos shortly.
This should solve your problem however.
Looking forward to get some photos :-)
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Old Jul 13, 2022 | 03:16 AM
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Backside of turn signal housing. Note the large white socket is the factory socket. as you can see it's offset to the left. the new socket is a socket I cut out of an old gauge. It holds a clear single filament LED bulb. Simply cut the running light wire off of the original twin filament socket and run to this new socket. Perhaps you can tell by the photo, this modification was done some 15 years ago. Still working fine.

Standard front running/turn bulb on the left. replacement mini bulb on the right. with the standard size bulb the white light shown through the amber bulb creating a amber edge on the front light. With the mini bulb no issues. These mini bulbs were used in Harley's with custom signal lights. Try an aftermarket Harley type work shop to locate them. The drag Specialities part number is on the box. I bought a box of 10 15 years ago. I have 7 left.
With 2 separate sockets. your amber bulb will go out completely. even if your running lights are on.
Got me compliance in Australia.


Last edited by 4-vettes; Jul 13, 2022 at 03:26 AM.
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Old Jul 13, 2022 | 03:35 AM
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OK. trying to get good photos of turn signal lights seems near impossible. And posting a video on here is beyond my talents. But here's my best shot.

Front light with just running lamp lit. it's white now instead of amber which makes the Australian government happy.

Best attempt at getting a photo of the amber signal. I assure you it looks much better in real life. And goes out completely with running light on or off. As now running light is white there is no confusion.

Rear lighting solution, Also need amber signals in the rear here. Also a twin socket setup. In this photo tail light only is on.

And signal flashing, once again, very hard to photograph.
Hope this helps.
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Old Jul 13, 2022 | 03:40 AM
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Originally Posted by 4-vettes
OK. trying to get good photos of turn signal lights seems near impossible. And posting a video on here is beyond my talents. But here's my best shot.

Front light with just running lamp lit. it's white now instead of amber which makes the Australian government happy.

Best attempt at getting a photo of the amber signal. I assure you it looks much better in real life. And goes out completely with running light on or off. As now running light is white there is no confusion.

Rear lighting solution, Also need amber signals in the rear here. Also a twin socket setup. In this photo tail light only is on.

And signal flashing, once again, very hard to photograph.
Hope this helps.

Thanks. If you want, you can upload to YouTube, and link the video here, that's easy enough :-) i would love to see it live, and show it to my MOT guy before i do the job.

So that new plug you added holds the daytime running lights, and the new orange bulb is in the original socket, and when you blink, the orange bulb is so powerful, it blinks so bright, it overrules the white led?

Last edited by Simonp3; Jul 13, 2022 at 03:50 AM.
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Old Jul 13, 2022 | 03:52 AM
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Wouldn't have a clue how to upload on you tube. PM me with a Facebook messenger address. Would be easy to send you a video by messenger
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Old Jul 13, 2022 | 03:53 AM
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So that new plug you added holds the daytime running lights, and the new orange bulb is in the original socket, and when you blink, the orange bulb is so powerful, it blinks so bright, it overrules the white led?[/QUOTE]
Yes. definitely over powers the white.
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Old Jul 13, 2022 | 04:03 AM
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So, one of these in each lamp with a 5w white bulb in it, run the 9# wire to it, and a new ground. replace the original bulb with a orange bulb, Jobs done?
o, o
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Old Jul 13, 2022 | 05:21 AM
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Yes, cut a hole in the back of the light housing for the new socket. Cut the running light wire that went to the original socket, now send it to the new socket, new ground wire. Jobs done. I'll check the bulb I used for the new white running light. I'll get back to you.
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Old Jul 13, 2022 | 06:26 AM
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Switchback white/amber LED 1157s and a minor wiring change may solve the DRL problem. 78 and 79 have clear front lenses. My 80 makes the DRL mode look green in the video, but they'd be white when I convert my wife's 79.


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