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Blinker problems

 
Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/08/11 05:10 PM

I have a '78 Chevy G20 van. I cant get the blinkers to work, the hazard's will kick on if I pull the switch.  I replaced the turn signal relay. I also checked the bulbs, two out of eight are burnt out but the hazards still work so there fine. I just cant get the blinkers to do anything.  I hope its not the switch inside the steering colum.  any ideas would be appreciated. Thanks!  

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68scott385
I have an SS396 tatoo
Posts: 325
Joined: 07/09
Posted: 01/08/11 07:58 PM

Did you check the fuses?
Did you check the BIG connecter under the steering column?  The pigtail from the turn signal swith to the harness is wide and contains about 15 wires, I've seen one side be making contact while the wires on the other end were not.  
68scott385 68scott385 68scott385

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/08/11 09:53 PM

which flasher did you change......    there are 2 flashers....  

the turn signal flasher is powered by the turn signal  fuse...

the hazard flasher is powered by the same fuse for the brake lights...



to tell the difference.. turn on the hazards...    feel the flashers.. the one thats not clicking is the turn signal flasher..  

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wally0143
My first time was in a Chevy
Posts: 186
Joined: 07/09
Posted: 01/09/11 10:02 AM

+1 wayne.  
Nobody knows everything but everybody knows something

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Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/09/11 06:09 PM

Like I said before, I replaced the Blinker relay, not only does it say witch is witch on the fuse panel but I turned the hazards on and felt to tell if what was clicking.  The hazards do work, I thought the fuzes were good.  (I pulled them out and looked) the only one thats blown is for the horn.  waynep7122 your saying that the blinkers and the hazards run off separate power? (sepaerate fuses) so if the hazards work that doesnt directly mean that the blinkers will??  Further more, in the harness underneath the dash, is there seperate power wires for the hazards and the blinkers?? If there wasnt this would point right to the switch under the wheel, there could be a short there.  Thanks for the help, I'll try a few more things before I rip the steering wheel off.  Thanks again!!  

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Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/09/11 06:13 PM

I will also go today after work and buy a whole set of fuses and relace all of them to rule that out.  Are shorts common in the fuse panel?? just thought I would ask.  Thanks again Grin  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/09/11 06:30 PM

here is the wiring diagram that should cover your van..

http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/07/b9/3a/large/0900c1528007b93a.gif  

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/09/11 06:34 PM

the directional flasher sends power to the purple wire into the turn signal switch..

the hazard flasher sends power to the brown wires into the turn signal switch..

the brake light circuits comes in on the white wire into the turn signal switch...

there are for sure 2 flashers in that system..

copy and paste the wiring diagram i linked above...

OR.. copy the entire text to an email.. send it to your self...  it will then be clickable...  

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Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/09/11 06:46 PM

Wow wayne thanks ALOT! I think that should do it, if not you'll be hearing from me again.  BIG HELP!   Grin  Grin  

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Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/14/11 01:34 PM

Ok i read the diagram, it explains alot, but I'm not clear on a couple wires.  There the last two on one end of the harness,  its unbolted so i dont know what the left or right is,  but there the white and green wires.  They have definatly got pretty hot and I had to peel them apart. I dont think that they grounded eachother but there could be a short in the harness.  Do any of you know off the top of your head what them two wires do? Thanks  

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Ron1973
I have an SS396 tatoo
Posts: 257
Joined: 09/10
Posted: 01/14/11 02:13 PM

On the diagram waynep gave you, each wire tells the color of the wire, abbreviated such as green GRN or light green dark green LT GRN OR DK GRN, this should give you an idea what are the ones your looking for and where they go, white is WHT. you may have to plug it back in to find out left and right to trace them, hope this helps some.  
____________________
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Ron1973

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/14/11 06:33 PM

I don’t have the exact order right at hand…

Purple directional from turn signal flasher

Brown hazards   from hazard flasher

White from brake light switch….

Light blue is the left front turn signal

Dark blue is the right front turn signal

Yellow is left rear brake light and turn signal

Dark green is the right rear brake light and turn signal.

many parts stores sell the replacement turn signal switch..


if it does not have a tilt column.. the turn signal switch is only 30 bucks at AZ... with a tilt.. its 80...

which is strange as they are almost identical..  almost..


the turn signal flasher is usually a different flasher number than the hazard flasher...

i normally install 552 flashers in both locations..

with ANY burned out bulbs.. there may not be enough current to properly active the flasher..

let me explain...   the flasher has a tiny resistance wire wrapped around a chunk of bent bimetal spring..  

when you active the turn signal switch.. or the hazard switch...

current flows through the circuit... from ground.. through the bulbs.. through the switch.. through the flasher.. to the fuse.. to the battery/ or ignition switch...

the current load passing through the flasher heats the bent bimetal strip inside causing one side to expand a little faster than the other side.. this expansion causes the bend in the metal to pop the other way... when it does.. the current flow stops.. the metal cools and the metal bends back.. making contact and heating up again...  this is how the flasher works...

if you have burned out bulbs..   there may not be enough current draw coming through them to heat the flasher internal parts to get them to pop open.. this usually results in a turn signal light that stays ON.. except for the burned out bulbs that are dark because they are burned out..

without the proper load.. the turn signal flasher will not cycle...

since the hazards flasher activates more bulbs... it will usually work with a few bulbs burned out..

this is one of the ways that i can tell which bulbs are burned out.. i reach in.. turn on the parking lights... and then the hazards....      it will go from DIM to BRIGHT...    if one side goes out.. then you have a bad ground on that side...   some times that only works when the parking lights are on.. and you step on the brakes...

if you have 2 test lights...   warning this can melt one... i normally have one test light with a 212-2 bulb in it.. this draws enough power to properly test the turn signal flashers.. but will let the smoke out of any computer controlled item.. including the lights on 2000 and newer cars that are computer operated with the CAN system... not a problem on yours..

the 212-2 bulb will fit into many but not all circuit testers...   it gets hot enough in 30 seconds to start melting the plastic body of the tester...  but for testing the turn signals and a few other NON COMPUTER circuits.. it works great...  

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Michigander79
V-6 Camaros rule!
Posts: 55
Joined: 12/10
Posted: 01/16/11 01:41 AM

You guys are damn smart, I got all the blinkers to work, but when I turn on the parking lights or the head light the right blinker just stops working?  Stumped me.  Oh and I cant get the left brake light to work.  I dont know, I replaced the bulbes and nothing.  All the fuses nothing. I must be missing a ground wire some where. This damn van is startint to piss me off!!!! Mad  Confused Thanks again for all the help.  

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idrivejunk
My first time was in a Chevy
Posts: 128
Joined: 04/10
Posted: 01/16/11 06:29 AM

Sounds like you have two bad bulb sockets to me.  
idrivejunk

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waynep7122
Everything in my driveway’s a Chevy
Posts: 556
Joined: 08/09
Posted: 01/16/11 09:29 AM

bad bulb sockets....   but not bad where you would think....  not bad between the wires in the bottom and the contacts on the bottom of the bulb...

but bad between the shell of the bulb and the body ground...

a few easy ways to check it....   got some spare wire from another project????  examine your sockets.. sometimes there is a place to stick another wire through the outer shell....    strip back the insulation on a spare piece of wire.. 3 or 4 inches...   take out the bulb.. wrap the bare wire around the base of the glass ball of the bulb.. right at the top of the brass shell...  twist the wire so its tight.. stick the end of the wire through the side openings in the tail light socket... and reinstall the bulb...   take the plain end of the new wire and ground it...  i like to put a proper crimp on terminal... but.. for this.. if you don't have one.. just wrap it tight around a loosened bolt and snug the bolt back down..   now try the tail lights and brakes....

remember.. electrons flow from ground to positive...    if you don't have a good ground...  when you active both circuits. one with a bad ground will go out...

but WHY....   tail light bulbs have 2 filaments...  almost all are grounded close to the tail lights..   if you loose one ground connection.. in the socket.. or elsewhere...  the tail light filaments are all hooked together.. individually grounded...   so the ground is made through the other filaments... while that circuit is inactive.. but when you power it up..  there is not enough path to continue to power the non grounded bulbs.. so the non grounded bulbs go dark...  this sounds complicated... its not.. its just the way it is....




/ brass | glass bulb\
C brass | filament    |
C brass | Filament   |
\ brass | glass bulb/

the filaments are both grounded through the brass shell of the bulb..



you can also wrap the top of the brass shell with the wire and ground the end for testing out of the tail light housing..

the problem is.. most people just think .. thats a ground.. i don't need that.  i have the power wires properly attached...   would your computer at home work... if you only plugged in one of the 2 flat blade terminals... nope..  house wiring is different than automotive wiring.. the ground in house wiring is a safety ground.. so any stray shorts are drawn away.. and cannot build up in the equipment and electrocute you ..

in automotive applications.. the ground side is half the circuit.. the side with the electrons...  loose or dirty grounds may not pass enough electrons to operate the device on the circuit ...  

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