79 Turn signal problem
Thread Starter
Intermediate
Joined: Mar 2007
Posts: 48
Likes: 0
79 Turn signal problem
I am still having trouble trying to fix my t/s problem. I have replaced my switch with (borrowed a new one), I have checked both my flashers, interchanged them. I have checked both of my tail light bulbs, the filiments both light up with the lights on and the hazards working. They work with either one also. Could this be a ground problem, and where should I look? Also my dash lights haven't worked since I purchased the car 2 years ago--could this be related? Please help--before I loose it
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
If your hazards work, and also the driving lights come on when you turn your headlight switch on. Where they both work independentally and together. CHECK YOUR TURN SIGNAL/ BACK UP FUSE IN THE FUSE PANEL. If the hazards are working then it is NOT the connector because the same wire that powers your hazards is the same wire that makes your turn signals work. In your turn signal switch connector the light blue and dark blue wires make your turn signals/ hazards in the front operate. The yellow and green wires make the lights in the rear operate. It must be a fuse or a corroded contact where the fuse clips into the fuse panel. I have seen many times that a water leak inside the car over time can cause the terminals in the fuse panel to corrode. I often times check to make sure that 12 volts is passing through the fuse by checking the power in side of the fuse and then check the power out side. The corrosion may allow a test light to shine but when checked with a volt meter I have had numerous cars have a drop in voltage to where my meter reads 7 volts, and things will not operate on 7 volts correctly if at all. Sometimes just toughing the fuse will correct this problem ( like it has for me) and I remove the fuse, clean the contacts and re-install the fuse.
The same holds true for your interior lights, The "iNST" or "INST LMP" fuse in your fuse panel is anywhere from a 5 to 7.5 amp fuse. I do not have my book here at home so I will have to have you contact me if it not still silkscreened on the fuse panel. This fuse is a dead circuit in the fuse panel. The only time this fuse gets power is when you turn your headlight switch on. It does not matter if the ignition is on or not. Your headlights are not controlled by your ignition switch, but the turn signals are, so the ignition need to be on when testing the turn signal fuse . If you find the fuse, and use your voltmeter, turn your headlight switch on. Power is now getting to the fuse to power your dash lights. If it does not, than it is either you have the setting to low, so turn the **** until you feel the detent. This should make your interior lights come on when you are inside the car with the door shut, like if you wanted to read a map of something. Rotate it back just slightly past the detent and now the dash lights will be there brightest. If you still have no dash lights and no power getting to the fuse it is your headlight switch. You can remove the fuse, (sometimes they are a pain) and check the terminal directly if you were having a hard time getting your leads into the fuse connector. If you still have no power on either of the fuse terminals, than it is the headlight switch. I have replaced more headlight switches than I can count due to that circuit being bad and yet all other functions of the switch are working. If your fuse is blown, and you install a new fuse and it blows, then some "bozo" in the past has caused your interior light circuit to be compromised. I have seen many times that somebody installs a new stereo, they cut the factory wiring and allow the light gray wire to be exposed to a ground because GM supplied a wire for the factory stereo lighting and new steroes do not require it. To verify for certain that it is a headlight switch or possible headlight connector that has a problem, you can get an in-line fuse and use a 5 amp fuse for safety. Connect one end of your in-line fuse to a known 12 power sorce and take the other end and touch the fuse connectors in the fuse panel one at a time. If the wiring is correct, when you touch the fuse connector the dash lights should light up because you are taking the headlight switch out of the equation. Call me if you need me, free of charge. "DUB"
The same holds true for your interior lights, The "iNST" or "INST LMP" fuse in your fuse panel is anywhere from a 5 to 7.5 amp fuse. I do not have my book here at home so I will have to have you contact me if it not still silkscreened on the fuse panel. This fuse is a dead circuit in the fuse panel. The only time this fuse gets power is when you turn your headlight switch on. It does not matter if the ignition is on or not. Your headlights are not controlled by your ignition switch, but the turn signals are, so the ignition need to be on when testing the turn signal fuse . If you find the fuse, and use your voltmeter, turn your headlight switch on. Power is now getting to the fuse to power your dash lights. If it does not, than it is either you have the setting to low, so turn the **** until you feel the detent. This should make your interior lights come on when you are inside the car with the door shut, like if you wanted to read a map of something. Rotate it back just slightly past the detent and now the dash lights will be there brightest. If you still have no dash lights and no power getting to the fuse it is your headlight switch. You can remove the fuse, (sometimes they are a pain) and check the terminal directly if you were having a hard time getting your leads into the fuse connector. If you still have no power on either of the fuse terminals, than it is the headlight switch. I have replaced more headlight switches than I can count due to that circuit being bad and yet all other functions of the switch are working. If your fuse is blown, and you install a new fuse and it blows, then some "bozo" in the past has caused your interior light circuit to be compromised. I have seen many times that somebody installs a new stereo, they cut the factory wiring and allow the light gray wire to be exposed to a ground because GM supplied a wire for the factory stereo lighting and new steroes do not require it. To verify for certain that it is a headlight switch or possible headlight connector that has a problem, you can get an in-line fuse and use a 5 amp fuse for safety. Connect one end of your in-line fuse to a known 12 power sorce and take the other end and touch the fuse connectors in the fuse panel one at a time. If the wiring is correct, when you touch the fuse connector the dash lights should light up because you are taking the headlight switch out of the equation. Call me if you need me, free of charge. "DUB"
Drifting
Joined: May 2006
Posts: 1,480
Likes: 2
From: Circleville Ohio
Vader vette
That last post ,great job just to long to read to see if he tells you to check the back bumper grounds they were bad on my 75 the lights would come(In the speedometer area) on but not flash at the back cleaned the grounds no problem try that metal part of the bumper look for wires running to A ground post or just A bolt. good luck
Race Director
Joined: Mar 2006
Posts: 14,112
Likes: 28
From: Florida
If your hazards work, and also the driving lights come on when you turn your headlight switch on. Where they both work independentally and together. CHECK YOUR TURN SIGNAL/ BACK UP FUSE IN THE FUSE PANEL. If the hazards are working then it is NOT the connector because the same wire that powers your hazards is the same wire that makes your turn signals work. In your turn signal switch connector the light blue and dark blue wires make your turn signals/ hazards in the front operate. The yellow and green wires make the lights in the rear operate. It must be a fuse or a corroded contact where the fuse clips into the fuse panel. I have seen many times that a water leak inside the car over time can cause the terminals in the fuse panel to corrode. I often times check to make sure that 12 volts is passing through the fuse by checking the power in side of the fuse and then check the power out side. The corrosion may allow a test light to shine but when checked with a volt meter I have had numerous cars have a drop in voltage to where my meter reads 7 volts, and things will not operate on 7 volts correctly if at all. Sometimes just toughing the fuse will correct this problem ( like it has for me) and I remove the fuse, clean the contacts and re-install the fuse.
The same holds true for your interior lights, The "iNST" or "INST LMP" fuse in your fuse panel is anywhere from a 5 to 7.5 amp fuse. I do not have my book here at home so I will have to have you contact me if it not still silkscreened on the fuse panel. This fuse is a dead circuit in the fuse panel. The only time this fuse gets power is when you turn your headlight switch on. It does not matter if the ignition is on or not. Your headlights are not controlled by your ignition switch, but the turn signals are, so the ignition need to be on when testing the turn signal fuse . If you find the fuse, and use your voltmeter, turn your headlight switch on. Power is now getting to the fuse to power your dash lights. If it does not, than it is either you have the setting to low, so turn the **** until you feel the detent. This should make your interior lights come on when you are inside the car with the door shut, like if you wanted to read a map of something. Rotate it back just slightly past the detent and now the dash lights will be there brightest. If you still have no dash lights and no power getting to the fuse it is your headlight switch. You can remove the fuse, (sometimes they are a pain) and check the terminal directly if you were having a hard time getting your leads into the fuse connector. If you still have no power on either of the fuse terminals, than it is the headlight switch. I have replaced more headlight switches than I can count due to that circuit being bad and yet all other functions of the switch are working. If your fuse is blown, and you install a new fuse and it blows, then some "bozo" in the past has caused your interior light circuit to be compromised. I have seen many times that somebody installs a new stereo, they cut the factory wiring and allow the light gray wire to be exposed to a ground because GM supplied a wire for the factory stereo lighting and new steroes do not require it. To verify for certain that it is a headlight switch or possible headlight connector that has a problem, you can get an in-line fuse and use a 5 amp fuse for safety. Connect one end of your in-line fuse to a known 12 power sorce and take the other end and touch the fuse connectors in the fuse panel one at a time. If the wiring is correct, when you touch the fuse connector the dash lights should light up because you are taking the headlight switch out of the equation. Call me if you need me, free of charge. "DUB"
The same holds true for your interior lights, The "iNST" or "INST LMP" fuse in your fuse panel is anywhere from a 5 to 7.5 amp fuse. I do not have my book here at home so I will have to have you contact me if it not still silkscreened on the fuse panel. This fuse is a dead circuit in the fuse panel. The only time this fuse gets power is when you turn your headlight switch on. It does not matter if the ignition is on or not. Your headlights are not controlled by your ignition switch, but the turn signals are, so the ignition need to be on when testing the turn signal fuse . If you find the fuse, and use your voltmeter, turn your headlight switch on. Power is now getting to the fuse to power your dash lights. If it does not, than it is either you have the setting to low, so turn the **** until you feel the detent. This should make your interior lights come on when you are inside the car with the door shut, like if you wanted to read a map of something. Rotate it back just slightly past the detent and now the dash lights will be there brightest. If you still have no dash lights and no power getting to the fuse it is your headlight switch. You can remove the fuse, (sometimes they are a pain) and check the terminal directly if you were having a hard time getting your leads into the fuse connector. If you still have no power on either of the fuse terminals, than it is the headlight switch. I have replaced more headlight switches than I can count due to that circuit being bad and yet all other functions of the switch are working. If your fuse is blown, and you install a new fuse and it blows, then some "bozo" in the past has caused your interior light circuit to be compromised. I have seen many times that somebody installs a new stereo, they cut the factory wiring and allow the light gray wire to be exposed to a ground because GM supplied a wire for the factory stereo lighting and new steroes do not require it. To verify for certain that it is a headlight switch or possible headlight connector that has a problem, you can get an in-line fuse and use a 5 amp fuse for safety. Connect one end of your in-line fuse to a known 12 power sorce and take the other end and touch the fuse connectors in the fuse panel one at a time. If the wiring is correct, when you touch the fuse connector the dash lights should light up because you are taking the headlight switch out of the equation. Call me if you need me, free of charge. "DUB"
Correct me if I'm wrong, but
If you double check, I'm sure you will find that the hazard and turn signals are powered to the column by separate wires, so yes, it can still be in that connector. It is often one of the first places to look after the fusebox.
