79LittleRedCorvette

In my 79, my right turn signal does not work in the front at all with headlights off, but works fine in the rear.

With my headlights turned on, the right turn signal stays lit constantly in the front. When I turn my right turn signal on (with headlights on), the right rear tail light, brake light, and turn signal do not work. The right indicator light on the dash stays on constantly with headlights on as well.

The left turn signal works fine at all times.

I recently replaced my headlight switch and I just replaced the turn signal flasher, but nothing changed. What should I try next?

hugie82

Wiring is NOT my specialty but on the drivers side behind the headlight, the main wiring harness comes thru the rad support. Right where it starts turning and branches off to the drivers side headlight is a known problem area. The wires break in that harness in that area. Try playing with it to see if the lights change.
Other than that, corvettes have ground wires everywhere. Start checking them too

DUB

You more than likely have a ground problem in the front right bulb socket. VERIFY that the black wire that is your ground is actually supplying a ground to the inside of the socket when the bulb is removed...and the bulb can only be installed CORRECTLY ONE WAY.

Get your turn signal working FIRST WITHOUT the headlight switch turned on..then give results when you turn your headlight switch on.

DUB

79LittleRedCorvette

Thanks! Do I just verify this visually looking in the socket with the bulb removed or with a test light or multimeter?

79LittleRedCorvette

Thanks! I'll be sure to look there.

DUB

Use a volt meter....to make sure that you are getting ground to the socket.

You can even switch light bulbs and verify that the bulb on the bad side works on the good side.

DUB

MELKELMAY

Not to Hyjack your thread, but I have a similar problem. Both my turn signals work when I have the headlights off, but when I turn them on they will not work. The Hazards will work with headlights on or off. I changed my Turn Signal Switch because Bubba has been in my car, but have not been able to track down the issue.
I was hoping DUB could help me out also! From other posts I have seen... he is the man when it comes to the wiring!

79LittleRedCorvette

Ok, so I finally got a chance to look at it and I noticed a tear in the wire that connects to the front right socket. I cut and repaired it and it worked fine, but then went out again from wiggling the wire. The whole connector is in really bad shape, so I pulled it. Everything on the rear now works fine! I also pulled the left front socket because I noticed the parking lights do not come on at all on that side. I plan to order a new wiring extension for both sides and it should fix my problem. Also, with both sockets removed, both indicator lights in the dash are on. That problem should go away also with all new sockets. I'll update once I get the new parts in and running. Thanks for the help!

79LittleRedCorvette

So it looks like there is probably a short or bad ground in your wires too. you should maybe unplug the wiring connector to the park/turn signal lights. It is connected to a harness about 15 inches above and really easy to disconnect. I could not reach it from underneath, but was very easy to get to from the top with the hood raised. If that is your problem, all rear lights and blinkers should work correctly. Both sockets are sold as a pair at zip-corvette for just under $50.

DUB

IF you have turn signals working when you use them with NO HEADLIGHTS ON...GREAT.

BUT...if when you go and turn your headlights ON...and ALL the appropriate lights come on when you do so...and try to use your turn signals and they do not work...you have GROUND PROBLEM! Usually in the socket(s)..but not always.

The reason your turn signals are working when the headlights are OFF is because...the turn signals are using the un-used filament in the bulb (1157)...and getting the ground through that filament....which is your driving/park light filaments in the bulb...BUT...when you turn your headlights ON....that filament is being used....and it is working BECAUSE it is finding a GROUND through your filament for your turn signals....SO..when you try to use your turn signals...there is NO GROUND...because you actually have NO GROUND getting to the section of the socket that grounds the brass section of the bulb.

I have also had to get into columns to replace turn signal switches due to "BOZO" got int there and messed it all up. I usually just plug in the turn signal switch connector at the base of the column and do all my testing BEFORE I actually install it.

Brake light, turn signals and hazards ALL use the same filament in the bulb. Driving,running light use other filament.

DUB

DUB

That should do it.

DUB

MELKELMAY

Thanks so much for the explanation. That helps tremendously! I can't wait to get out there and see if that is my problem and sure it is, but won't be until next weekend. Work calls! Ha

DUB

If it does not work...please reply stating as such. But I would bet it is a ground issue.

DUB

ricrx7

I am having the same problem - turn signals work when headlights off and do not flash with headlights on. I disconnected all 4 headlights and the turn signals still do not flash. Is your explanation of a bad ground the same whether the headlights are connected or not?

DUB

Disconnecting the headlights will do nothing to help you in this issue. You have a bad ground a t a bulb or two...or a connector that is contaminated and can not flow current...so the reason your turn signals are working without the headlights on..is because it is finding a ground through the filament in the running light portion of the 1157 light bulb....when you turn on your headlights...the running lights light up...but there is now NO ground for your turn signals...which is why they do not work.

IT IS A GROUND...or bad bulb...or bad wiring....but more than likely a bad ground at the socket.

DUB

MELKELMAY

So one more stupid question that is going to help me out tremendously.... The sockets. Are you talking about the tail light\turn signal sockets?

Thanks again!

DUB

YES...you need to check the grounds in the four sockets...rear taillights and front turn signals.

Let me know what happens.

DUB

ricrx7

I removed all rear lights including side lights and the turn signals work. So bad ground should be in the rear? I checked the rear taillights and the ground reads as a ground. When I plug in any of the bulbs in the rear, the turn signals stop working.

Can you suggest where to look next? Is it a clue that when the left rear bulb is plugged in both filaments light. When I plug in right rear bulb only one filament lights.

DUB

What do you mean that the turn signals work...how can they if your rear bulbs are out...or are you saying the front turn signals NOW work. You have to be precise.

LIGHT BULBS 101 in session.

If you are checking the ground portion of a light socket..and you have bulbs still in the car...it will show a ground because it is finding a ground through one of the bulbs that you have not removed. Remember that one end of the filaments connect to the socket that grounds...and the other end of the filament goes to the terminal at the end that gets power.

Did you remove the license plate light? if not...there is a ground.

Using a test light...you can connect it to the ground portion of a socket you are testing...and have the turn signals going for the side you are testing...and then take the pointed end of the test light and touch the terminals (one at a time) and your test light will flash AS LONG AS that ground on the socket is GOOD. Then...if you turn on your headlights...the other terminal in the socket will light up..because it is your running light. IF all is good...plug in a light bulb and it should be working. Then remove the bulb and test the other sockets.

I would have to bet you have a ground problem.

DUB

ricrx7

Yes, the front turn signals worked with the rear bulbs out. From previous experience, I know the ground in the tail light sockets is not very good, so I ground away the plastic and soldered the ground connection. I now have rear turn signals with the headlight switch on. Or at least I have it for a single light on each side.

I have converted my rear lights to 4 brake/turn signals. I used a "Y" arrangement to keep the original socket. So I have two bulbs plugged into one socket on each side. With these plugged in, my turn signals will not work.

Do I need to add more or larger ground wires to support the 4 lights?

Thanks.