Blinking headlights?

[Helirich]

Last nite my headlights started blinking. Seemed to be related to vibration which would lead me to a bad connection. Is there any other thing that has a history of this. (Relay or dash switch)

[Bitsyncmaster]

I assume it was random blinking. You could narrow the problem down by testing if high and low beams do the same. If so then you could jumper one headlight relay and test again. If the jumpered relay fixes it then the problem is at or before the relay.

[AugustneverEnds]

Do you have the original light switch? If you do, I'd start looking at it and see if it's melting. If you have the DMCH updated switch check its fuse

[glockworks21]

Last nite my headlights started blinking. Seemed to be related to vibration which would lead me to a bad connection. Is there any other thing that has a history of this. (Relay or dash switch)

I had similar issue a couple months ago and just pulled and cleaned connectors at relay. Has not happened since.. Ive since went through and cleaned all the connections.. Hopefully its that simple..


Merry Christmas..

[Helirich]

I assume it was random blinking. You could narrow the problem down by testing if high and low beams do the same. If so then you could jumper one headlight relay and test again. If the jumpered relay fixes it then the problem is at or before the relay.

It was random. I pulled over and felt some of the relays to see if any were hot. (Just warm) when I got back out on the road it was fixed for a few miles and started again. I need to look up the headlight relays. I think I might have yours. If you make them. I know I bought most of the relays you sell.


Do you have the original light switch? If you do, I'd start looking at it and see if it's melting. If you have the DMCH updated switch check its fuse

Yes, this is what I?m most suspect of. I do have LED lights, so there shouldn?t be a lot of power draw.


I had similar issue a couple months ago and just pulled and cleaned connectors at relay. Has not happened since.. Ive since went through and cleaned all the connections.. Hopefully its that simple..


Merry Christmas..

This sounds like good advice.

[DMC-Ron]

Headlight load is handled by the two relays (main beam relay and dip beam relay) so their current does not go through the switch contacts. However, current for all the other running lights does go through the main lighting switch. When you add up all the running lights and side lights they can draw quite a bit of current, especially if these still have incandescent bulbs. This load is the reason for the common failure of the switch. However, the actual internal contact in the main lighting switch that operates the headlights has only the relative minor load of the headlight relay coils. If only the headlights were blinking, and not any of the other lights, one would suspect the headlight relay or fuses.

Was the blinking only when you had low beams on, high beams only, or did it blink regardless of high or low? If it was just one (high or low) that blinked, swap the relays and see if the issue remains or moves with the relay. If it moves with the relay, replace the relay. If it doesn't, try cleaning and swapping the fuses.

Good luck, Ron

70252

[Helirich]

Headlight load is handled by the two relays (main beam relay and dip beam relay) so their current does not go through the switch contacts. However, current for all the other running lights does go through the main lighting switch. When you add up all the running lights and side lights they can draw quite a bit of current, especially if these still have incandescent bulbs. This load is the reason for the common failure of the switch. However, the actual internal contact in the main lighting switch that operates the headlights has only the relative minor load of the headlight relay coils. If only the headlights were blinking, and not any of the other lights, one would suspect the headlight relay or fuses.

Was the blinking only when you had low beams on, high beams only, or did it blink regardless of high or low? If it was just one (high or low) that blinked, swap the relays and see if the issue remains or moves with the relay. If it moves with the relay, replace the relay. If it doesn't, try cleaning and swapping the fuses.

Good luck, Ron

70252

I never turned on the high beams. I didn?t see if the running lights blinked. (They are LED also) I want to say the instrument lights did not blink, but can?t even say for sure about that. It?s the first time I drove the car in a month and everything was going great all day. It kind of ruined my perfect day. It was not scary because of a bright full moon. I could have turned them off and continued driving, but it?s irritating.

[r00b]

This can happen if you get blinker fluid on the headlights.

[glockworks21]

verdict?

[Helirich]

I havnt even looked at it yet. I?m out of town right now for the holidays.

Happy New Years!

[Helirich]

Reviving an old thread that I never fixed. The daytime running lights are so bright, I can drive by them. I still would like to fix this. The other night I tried them and found that high and low beams blink. I also found that they stop blinking when I turn off the motor. Very strange. The car doesn?t vibrate much and the blinking doesn?t seem to very by rpms. I was going to order a new headlight switch, but apparently, they are not available. I still havnt checked the relays.

[Bitsyncmaster]

If your headlights are LED, they use a switching power supply to drive them at a constant current. If both headlights are doing the same thing, it would be my guess the voltage to them is to low or to high for some reason. Since it just seems to do it with the engine running, my guess would be to high. What is does your volt gauge read with the engine running?

[Helirich]

If your headlights are LED, they use a switching power supply to drive them at a constant current. If both headlights are doing the same thing, it would be my guess the voltage to them is to low or to high for some reason. Since it just seems to do it with the engine running, my guess would be to high. What is does your volt gauge read with the engine running?

So my voltage when the engine is running is about 14.3v plus or minus .1v

Does that seem too much?

I checked the fuses and relays. They all look fine. I guess my next step is to bypass the headlight switch to see if it continues.

[Bitsyncmaster]

So my voltage when the engine is running is about 14.3v plus or minus .1v

Does that seem too much?

I checked the fuses and relays. They all look fine. I guess my next step is to bypass the headlight switch to see if it continues.

I would not think that voltage is high. My car runs about 14.6 volts at idle. I would think the headlights can work at 15 or higher voltage.

[Helirich]

So I pulled the switch and made a jumper to bypass it. Lights still blink if the motor is running. Both high and low beams blink and they blink exactly the same time. I don?t see how two separate relays could go bad the same way. I?m at a loss here. Not sure what my next step is.

[DMC-Ron]

So I pulled the switch and made a jumper to bypass it. Lights still blink if the motor is running. Both high and low beams blink and they blink exactly the same time. I don?t see how two separate relays could go bad the same way. I?m at a loss here. Not sure what my next step is.

Helirich, yes, that is perplexing. You're saying you notice the blinking when the high beams are on (All four headlights), and you notice the blinking when you switch to low beam (outer headlights on). Separate fuses, separate relays, separate wiring, separate filaments. Also it's not clear if the blinking you're describing is a full on/off/on blinking, or more of a flutter? Can you detect any blinking or fluttering in the other running lights(side markers, taillights, and front signal)? I take it there is no blinking without the engine running. If it seems there is a bit of flutter in everything, I would be suspicious of a bad alternator diode. Could you try removing the alternator belt and running the engine to see if the lights still blink? If they stop blinking, then it seems you should focus your troubleshooting on the charging system.

Ron

[FABombjoy]

Do you hear the headlight relays click when it happens?

If the relays are silent I'd look at the headlight grounds to be sure they're clean and the bolts are tight. Then the headlight harness common connector to make sure it's also clean and fully locked together.

LEDs are very ON or OFF and take way less current, so you could have a connection right on the edge and vibration from the engine running / driving can make or break the connection.

[Helirich]

Helirich, yes, that is perplexing. You're saying you notice the blinking when the high beams are on (All four headlights), and you notice the blinking when you switch to low beam (outer headlights on). Separate fuses, separate relays, separate wiring, separate filaments. Also it's not clear if the blinking you're describing is a full on/off/on blinking, or more of a flutter? Can you detect any blinking or fluttering in the other running lights(side markers, taillights, and front signal)? I take it there is no blinking without the engine running. If it seems there is a bit of flutter in everything, I would be suspicious of a bad alternator diode. Could you try removing the alternator belt and running the engine to see if the lights still blink? If they stop blinking, then it seems you should focus your troubleshooting on the charging system.

Ron

Good idea! I was thinking of jumping a running car to the battery so I could get the voltage up to 14 volts without running the motor. But I like your idea better.

I don?t think the sidelights or dash lights are blinking. But I will check. The sidelights lights are also LED, but my dash lights are stock.

My headlights have a LED stripe in the middle that is for the daytime driving lights. That stripe is not blinking ever. When I turn on the headlight, that stripe turns off. Not sure how that is done. I didn?t do any fancy wiring. There is one extra wire that I wired to my accessory power, so it doesn?t go off. Maybe there?s some kind of computer chip in the light?

[Helirich]

Do you hear the headlight relays click when it happens?

If the relays are silent I'd look at the headlight grounds to be sure they're clean and the bolts are tight. Then the headlight harness common connector to make sure it's also clean and fully locked together.

LEDs are very ON or OFF and take way less current, so you could have a connection right on the edge and vibration from the engine running / driving can make or break the connection.

I will check, but I don?t understand how they could not be working if the lights come on. I suppose if the ground was to the same location and it was slipping.

[Helirich]

Ok, I pulled the alternator belt and started the car. No blinking.

I also felt the relays and they click when I turn the lights on. I don?t know if they make much noise. I couldn?t hear em, but it was raining on my metal roof.

[FABombjoy]

My headlights have a LED stripe in the middle that is for the daytime driving lights. That stripe is not blinking ever. When I turn on the headlight, that stripe turns off. Not sure how that is done. I didn?t do any fancy wiring. There is one extra wire that I wired to my accessory power, so it doesn?t go off. Maybe there?s some kind of computer chip in the light?
Oh, yes this is a detail that changes the troubleshooting approach since it's not the typical headlight circuit now.

[DMC-Ron]

Ok, I pulled the alternator belt and started the car. No blinking.

I also felt the relays and they click when I turn the lights on. I don?t know if they make much noise. I couldn?t hear em, but it was raining on my metal roof.

My headlights have a LED stripe in the middle that is for the daytime driving lights. That stripe is not blinking ever. When I turn on the headlight, that stripe turns off. Not sure how that is done. I didn?t do any fancy wiring. There is one extra wire that I wired to my accessory power, so it doesn?t go off. Maybe there?s some kind of computer chip in the light?

Helirich,
Normally I would be suspicious of a bad alternator diode. But, with a bad diode, you should notice some flutter in the LED running lights, which you don't. Still, there is a quick diode test that would be worth trying using your multimeter:
1. Set your multimeter to AC Volts
2. Place the red probe on the battery's positive terminal and the black probe on the negative (You could use your cars jump start post and a good ground).
3. A reading of 0.5 volts AC or higher indicates a bad diode. A healthy alternator typically shows less than 0.1 AC volts to 0.3 AC volts.

The LED stripe in your headlights has me wondering. I just finished helping a neighbor retrofitting his motorcycle with LED lights. There was an odd issue with the front turn signal light. These lights double as a running light and turn signal. There is a separate +12 for turn and run. Oddly, there was an interaction that did not allow the running lights to work when the turn signal circuit was connected. The reason turned out to be a ground path created by other bulbs in the turn signal circuit. We added a large diode in line with the turn signal connection to fix the issue.

Would it be possible for you to disconnect the assessory power to your headlight strip and see if that affects the blinking?

Ron

[Helirich]

Wow, I told a friend of mine about this and he said almost the same thing as above. He said the cut off point is .3 volts AC. Anyways, I checked mine and it was .47 volts AC. Just for fun, I checked my truck and it was .1 volts AC. Seems to check out. So I replaced the alternator and checked it. .07 volts AC. Great, but now for the real test. I turned on the headlights and no blinking!

Thanks guys.

[Bitsyncmaster]

Now you got my curiosity going. I went out and checked my car on AC volts. I get jumping between 0.045 and 0.050 volts AC. I just checked it on the cigarettes lighter. I never heard of this test before. I would have used my O-scope to look for a none full wave voltage. But most owners don't have that.

14.54 volts DC.

I forgot I had my lambda ECU removed (building up some more mini units). Boy the engine barely could run without it. Even backfired on start up.

[Helirich]

Now you got my curiosity going. I went out and checked my car on AC volts. I get jumping between 0.045 and 0.050 volts AC. I just checked it on the cigarettes lighter. I never heard of this test before. I would have used my O-scope to look for a none full wave voltage. But most owners don't have that.

14.54 volts DC.

I forgot I had my lambda ECU removed (building up some more mini units). Boy the engine barely could run without it. Even backfired on start up.

Dave, I know you are way over my head on this stuff. Is it possible that this AC noise could interfere with the ECU or other electronic stuff on our motors? Like causing hunting or something?

[Bitsyncmaster]

Dave, I know you are way over my head on this stuff. Is it possible that this AC noise could interfere with the ECU or other electronic stuff on our motors? Like causing hunting or something?

Not likely. The design of car electronics has to have circuitry to filter noise. This would include AC voltage noise and low and high DC voltages.

Obviously your headlights do not do this.