So I have one of those 7 wire turn signal switches that bolt onto the steering column, the front turn signals work fine , but the back are both flashing at the same time in either direction. One side seams brighter than the other for the side that it should be on. They are grounded to the frame? Help.
Did the turn lights on the back work correctly in the past and then start having this problem with no known human intervention or have they had this problem since they were installed?
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
Also make sure your "ground" connections are on well cleaned bare metal (no rust/paint/etc.).
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Are the rear lamps regular dual-filament lamps like 1034 or 1157? Or are they LED lamps?
Originally Posted by Luray
but the back are both flashing at the same time in either direction. One side seams brighter than the other for the side that it should be on.
Do these lines describe the problem? If signaling for a left turn, the left rear turn lamp is flashing bright and the right rear turn lamp is flashing dimmer? If signaling for a right turn, the right rear turn lamp is flashing bright and the left rear turn lamp is flashing dimmer?
Sorry to ask so many questions, but it is better to know as much as we can before getting into real troubleshooting.
One more, 6 volt or 12?
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
1157 bulb , yes the turn signal that the switch is switch to is brighter, other one dimmer, 12volt system, lights are grounded to frame ,all are on bear metal. Thanks
This may be hard to evaluate, but what happens to the brightness of the left rear turn signal when you remove the right rear bulb? Same, brighter or dimmer?
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
I don't under stand this sentence. "yes the turn signal that the switch is switch to is brighter"
For the rear (7 wire) 1. One wire from switch goes to left light, to the stop/turn filament. 2. One wire from switch goes to right light, to the stop/turn filament. 3. One to flasher L 4. One to flasher P 5. One to stop switch
For front 6. One wire from switch to right 7. One to left
One wire from the headlight switch goes to the rear and splits.... to left and right tail light filaments.
It's up to you to double check this. Post pix the instructions you are using if you still have trouble. Or give us the brand and model of switch.
If the switch is turned to the left the left bulb is brighter than the right and vice versa.
Don't under stand that either. please be careful and restate the trouble you are having. If there are no lights on and you move lever for left turn with foot not on brake, only the front and rear lamps flash. So what exactly are you saying? First of all, is the left front and rear flashing or not? Do brake light work or not? Have you double checked the wiring per my above or just assuming it's right?
Your issue was one side brighter than the other..WHEN? If you have running lights on and turn left, the right tail light is on and the left light is flashing. With a two filament bulb, the stop and turn filament is brighter than the tail light filament.
With no lights on , ignition switch on , turn signal lever turn to the left the front left turn signal flashes, the rear left turn signal flashes. The right front doesn't flash , right rear flashes, if I push the brake pedal the brake lights works.
Please re read my last post. Yes that is how I described wiring. Did you notice the part about bare metal on steering column? for switch to get ground.
With no lights on , ignition switch on , turn signal lever turn to the left the front left turn signal flashes, the rear left turn signal flashes. The right front doesn't flash , right rear flashes, if I push the brake pedal the brake lights works.
RECHECK WIRING.. Follow each wire. Don't assume it's correct. Assume you did something wrong so you will find it. Be sure each color goes to proper filament in rear. Be sure flasher is wired correctly... and is the correct one. If you see any thing not right, let us know.
The picture on the box that your switch came in is a Ford C-series truck!
1950 Chevrolet 3100 (Ol' Roy) 1939 Packard Standard Eight Coupe (The Phantom) | 1956 Cadillac Coupe de Ville (The Bismarck) | 1956 Cadillac Sixty Special Fleetwood (The Godfather) | 1966 Oldsmobile Toronado (The Purple Knif) | 1966 Ford Mustang (Little Red) | 1964 Ford Galaxie 500 coupe | 1979 Ford F-100 | 1976 Ford F-150 (Big Red) | 1995 Ford F-150 (Newt)
Next question, which will require removal of the red lens from the right tail light.
When you turn on the left turn signal are one or both of the filaments lighting up in the right tail light?
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
That's a problem. It should have a double filament bulb to work correctly. 2 hot wires going to it and a ground (or thru the body of the taillight).
[on edit] 0r did you mean only one filament lights up?
Last edited by klhansen; 01/12/202311:53 PM.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Consider the attwched wiring diagram. The dotted lines represent the bulb/housing. One wire should be attached to each filament and the common should be grounded (left diagram).
If you accidently reversed the ground and turn terminals then when you turned the left turn signal on, one filament on the left would flash and both filaments on the right would flash.
If you only reversed one side, then that turn signal would work correctly.
Given that you say the brightness is different between the sides, I suspect both are wired the same (incorrect) way.
Swapping ground and hot wires on an 1157 bulb would be hard to do as the ground is thru the socket. In order to do that, you'd need to isolate the whole taillight housing from it's attachment to ground. But a bad ground could easily light up both left and right bulbs. I would be double checking ground paths on both housings, including being absolutely sure that all paint is removed between the housing - bracket joint, the bracket - bed joint, and bed - frame.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
You are correct. If the ground was bad on one side, it would have the same effect because it would be trying to ground through the brake lights to the other side.
In that case, I would expect one side to make both flash and the other side to work.
Check your ground connections on rear lights. Sounds like you are getting backfeed causing the problem.
"Do not walk behind me, for I may not lead. Do not walk ahead of me, for I may not follow. Do not walk beside me either. Just leave me alone, you're starting to freak me out."