Hello all! Recently acquired a 51 and the wiring is pretty bad on it from previous owners. Eventually I will change wire harness but for now putting a bandaid on it. It has a turn signal added to it, Signal stat 900 with 7 wires. All turn and running lights work fine. I am getting no brake lights however. Checked the brake switch, works fine but noticed it only has a constant power lead going to it, nothing on the other terminal. So I suspect “ding ding ding” here is my issue. I don’t know where the other terminal should go though because I am reading that when a turn signal is added it needs to now pass through the turn signal to I assume override the blinker when brake is depressed? This is where I am confused. On the turn signal all wires are connected appropriately (I think from testing?) but there is a blue wire that goes nowhere. Tried connecting the blue wire to brake switch, nothing. Wouldn’t be surprised if it was originally wired incorrectly. Brand new rear lamps, single filament. 2 prong flasher. I don’t know if they ever worked with old rear lamps. Anyone out there know about these? I’m running around in circles here!
According to the wiring diagrams I find online, that blue wire is supposed to go to the flasher so it's miswired somehow. According to the 'net, red goes to right front, green to left front, black to right rear, grey to left rear. The blue should connect to your flasher, the yellow is the built-in indicator light and should also connect to the flasher (if it's a two wire flasher, leave it disconnected. You need a three wire flasher to connect it), and the black/grey goes to the brake light switch, which should have power already to it. If that's NOT the colors you have, or if it still doesn't work, you'll have to check the switch for each wire function; not that hard to do. Let me know and I'll lead you through it. You may have one more problem; single-filament lamps. Unless the tail and brake lights are in separate housings/sockets, you need two-filament lamps. Same goes for the fronts. If you have functioning park lights with single-filament lamps, you'll either have to disconnect the park light from the light switch, or install two-filament lamps/sockets and additional wiring.
Old thread on it here https://www.jalopyjournal.com/forum/threads/how-do-i-wire-a-signal-stat-900.200703/ From reading that the blue wire went to the turn light on the dash if there was one. Looking up the unit on line I see that he later units used a gray/black wire to the flasher. This diagram looks closer to what you have with that one http://jialong.me/wiring-diagram-fo...-900-wiring-diagram-cwatchblog-info-fair-for/ Problem is that they made a Signal Stat 900 for years but continually made changes and never seemed to change the model number. More like the 900 part meant bolt on switch.
Thank you, I will check the wires again to see if they are paired correctly. Regarding the tail lamps being single filament I purchased these: https://www.classicindustries.com/product/1951/chevrolet/truck/parts/ct25661.html I didn’t want the led look. They included 12v bulbs. It has a large single filament and small single filament. I believe small is running, large is turn and what I thought would be brake. 2 wires, grounded by the mounting. Is this true that it would have to be dual filament? Do they make such a thing for these older trucks, non led?
If the light assembly has two bulbs, then you don't need a dual filament bulb. The dual filament bulb lets you have tail lights and brake lights (and turn signals) in one bulb.
Yes that is a dual filament bulb. It should have two contacts on the bottom. That should be a 1157 bulb if it is 12 Volt and it is available at most any parts house and most discount stores like Walmart and even at some mini marts. Still if your turn lights work like they should and your tail slights work like they should the problem is in the Stoplight section somewhere. You said you had power to the switch. I am going to assume that you checked it with a volt meter or test light? Did you check the switch it's slef to make sure it is actually switching on and off? Old switches that have sat around for a while get corroded inside and sometimes doon't work. No problem you can pick one up at O'Reilly' Autozone or Napa, you might have to wait for the next freight load but it is not a specialty house only part. If you have power to the switch when you push the brake pedal you either have a switch problem or you have it wired wrong. I'm kind of leaning towards wired wrong as there seems to not be a lot of continuity in how they color coded them from what I can see.
I don't get married to color codes for just this reason. It's been more than once that I've found a part where the supposed color code didn't match up, even on factory parts. Want to check switch function and verify which wire goes where? Read this... : https://www.jalopyjournal.com/forum/threads/turn-signal-wiring-how-to.869492/ Use the 'six wire' instructions. You'll have one wire that won't read to any other wire, that will be the indicator light and will be the seventh wire. To test this wire, make sure the switch housing is grounded then touch that wire to a 12V source; the light should come on. And you have verified that the brake light switch works, right? It has power in, and power out the other side when the pedal is depressed?
Thank you everyone for your help! Both bulbs and sockets in this light assembly are single filament, see attached images. This I guess is my main concern now. Can you have tail, turn and brake lights from THIS light assembly with two single filament bulbs?! I have checked the switch, it works as it should. Power in is constant, power out turns on when depressed. But again nothing hooked up to the other terminal currently. The problem is still the brake lights, everything else works properly. If I change out the flasher to a 3 prong are my brake lights going to work? If I wire it correct, if it is not already, are my brake lights going to work? If not and I need new lights please provide a link to a 12v non led dual filament bulb assembly. View attachment 3950346 View attachment 3950347
Those rear lights will work. Not the most elegant solution, but functional. You still need to check the fronts. And the switch can still be miswired. Don't assume that because the turns work that the switch is hooked up correctly or even that the switch works right. I'd still check the switch according to the link I posted. Adding a three-wire flasher is only to allow the indicator light to operate, it won't effect the brake lights.
There needs to be a wire from the brake light switch, to the turn signal switch. and it needs to connect to the proper place on the turn signal switch. Think about how brake/turn signal lights work on cars from the 60s...the brake lights both go on if you push the pedal, and the turn signals are off. But when you turn on the turn signal on one side, the turn signal switch has to disable the brake light on the rear, on the side that has to flash. that's why the brake light switch wire goes through the turn signal switch. It can be confusing...take your time, you'll get it...
Here is an example of 7 wire switch Just as described above The stop function is handeled throught the 7 wire turn signal switch .
Ok that is what I get for assuming that the tail light has a dual element bulb in one socket rather than two single element bulbs in separate sockets but that has no bearing on the stop lights working. This is the drawing that i posted the link to in post #3 it is as close as i can find to your switch. It is still get out the tester and run though the tests that one would run though when tracking down the reason electricity doesn't go where you want it to go.
The only problem with the above diagram is if you connect the blue wire to the same place as the black on the flasher, the indicator light will be on all the time and will only flash when the turns are used.
Simple to trouble shoot...now...but when I was 13, 'all those wires' overwhelmed me. Now, it's a simple 'walk in the dark'!
Thanks guys, electrical has never been my strong suit but hoping all this will learn me some. I will start testing this weekend and will post back when fixed. Thanks again!
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