The Stovebolt Site Forums The Shop Area The Electrical Bay Can a 7 Wire Turn Signal Switch Work Like a 4 Wire Switch?

A few weeks ago when I restarted my long dormant 1951 3600 project I made a decision to start with the electrics. The 66 year old wires were bare in some areas and many components worked only sort of, some not at all. In addition current plans call for my keeping the truck and taking it with me when I "retire" to a more rural area. Needing good reliable electrics coupled with future plans to add an air conditioning unit & a radio meant 12v was going to be needed.

I found Deve's wonderful website and have been pouring over his section on rewiring the truck. At first I was going to follow his lead and make the stop & parking lights do double duty as turn signals and so bought a very nice 7 wire switch to do that. After some reflection on the nature or rural two lane roads at night where something called DARKNESS happens I decided to go bigger with the turn signals and add accessory units that would be much more visible. So now I need a 4 wire switch and just ordered one of those.

Well, too late I just got to wondering if the 7 wire job might work after all. Could I use it if I just didn't hook up the wires intended to go to the brake light switch?

As you might be able to tell from the question, I'm electrically challenged. Just the same, i think it might be fun to make this new harness & 12v conversion work.

I am not sure I understand your question,
4 wire switch does ONLY turn signal lights.
7 wire switch does the same but splits front and rear turn signals so brake lights can be incorporated.

YES, You can wire the 7-wire switch and not use the brake light circuit. You can also use the 7-wire with brake lights and add your additional turn signals as either turn only (wire them to come on with the front turn signals) or use as brake/turn (wire them to your rear turn signal/brake lights) .

I just want the separate blinkers and do not wish to involve the stop lights or parking lamps. How would the 7 wire switch be configured to do this? Having two switches to choose from would allow the one that looks most at home in the 1951 cap to get the nod rather than the one I happen to understand how to wire . . .

Be careful about which websites you accept as gospel. That one has some serious mistakes that the author refuses to correct.

If you really want to take a giant leap backwards by refusing to use the brake light discriminator circuit, just isolate the wire that would normally be connected to the brake light switch and wire the dedicated turn signals at each corner of the vehicle individually. It would be a much simpler (and more professional) option to wire the auxiliary lights as designed, which uses the turn signal on one side as a brake light and flashes the one indicating which way you intend to turn. The 7-wire system also has an emergency flash option which I believe the 4-wire system might not have.
Jerry

you can always hook up the 7-wire switch to your auxiliary turn signal lights exactly like it is designed, (if you only have fronts, only wire the fronts, etc) and just not hook up the wire going to the brake light switch. I agree with Jerry though, I would rather have more stop/turn signals than fewer and if I am slowing and turning left, I don't want a left brake light on solid for someone to see and not realize I am turning. I do live in a very busy high-traffic area though, and I like lights!

Please let me know what to watch out for on that wiring side of that site. I'm knee deep in this project right now and this is the time to make any changes before installing the harness & new bits in the truck.

Where I live right now darkness is a matter of degree. It never gets really dark, the city provides plenty of light 24/7. It is not unusual to see cars driving along without lights. You don't need'em to drive and they are of only marginal use in being seen. This past summer I did a lot of driving on country two lane roads where it is really DARK. You NEED headlights to see the road and other lights to BE seen. I knew all of this years ago but 40 years of living in the city had me forgetting it.

OK, that is why I decided to adapt this old truck to the situation I hope to be in in the near future.

I ordered a set of the 1951 style LED lights for the rear. I tried them on a battery and yup, they really ARE brighter. the next thing was to look for a set of large bright amber turn signals that would really stand out on a lonely two lane road at a distance at night. I found some great ones at a truck supply place. They even look vintage if you don't look too closely. Now I can let the brake lights be brake lights and not serve double duty as winkers. This is a HUGE step forward as far as safety & illumination are concerned.

Now I intend a completely separate circuit. Just to make sure I understand, I CAN use the 7 wire switch by simply not using the two wires intended for the stop light switch?

https://www.stovebolt.com/techtips/turn_signal.htm (Thank You, Charlie, RIP)

Some LED's require a different style of flasher to function properly. Combining LED's and regular incandescent bulbs on the same circuit can cause some problems, as I learned after wiring up a trailer with LED lights and getting no turn signal or brake light operation- - - -only tail lights. I've got to wring out the whole circuit again- - - -and I've been working on wiring and teaching automotive electricity for over 40 years.
Jerry

Japanese and European cars separate the rear turn signal light from the brake lights so I don't think it's a big deal. Only issue I had was connecting a trailer to a Toyota where we had to buy an electronic module to combine the light function back to the North American norm.

I know I'm electrically challenged but I'm still not clear on how to wire a 7 wire switch to work JUST the separate turn signals with no involvement of the brake lights. Do I just ignore the two wires supposed to go to the brake switch? I don't hook them together?

I'm confused. In your first post, you said you ordered a 4 wire switch so why does it matter how the 7 wire switch is wired?

Anyhow, here is a link to site with wiring diagrams for both types.
Signal Wiring

To use the 7 wire as a 4 wire just ignore the black, grey, and black/grey wires. Tape the ends so they don't short out. Red wire goes to both right turn lights and green goes to both left turn lights.

(wire colors seems weird to me. I would think that red is port (left) and green is starboard(right) )

Here's instructions from a NOS Signal Stat 900 I have for my GMC.

The 7 wire switch gives you more options now or in the future.
I'd go ahead and wire it in as instructed, even if you don't connect lights to the ends of everything.
If you ever have a trailer it'll be extra handy to have that already done, Or if you want more or different turn signals.

Thanks guys, I think I have it now. I CAN use the switch should I need or choose to.

Grigg - I have saved the instructions, thank you for posting them.

Gord wondered about my reasons for wanting to know. There are three - curiosity, redundancy & choice. I'm going to keep the 7 wire switch, there is nothing wrong with it and it is not fair to the seller to return it because I changed my mind. Now I know I can use it, I may decide to use it on this project. As Grigg pointed out, it gives more choices.

I'm taking my 51 to Germany and i need to separate the turn signals from the brake light AND the turn signals need to be Yellow ! Has anyone ever done this ? I'm going to modify my existing 7 wire system that is working to a 4 wire system with separate rear lamps and modify the front running light to have dual element bulbs (1154)... I'm going to modify all the flasher stuff and disconnect the break light connections and have to run new wires to from and rear, what a pain... you need yellow turn signals (on the outside) , red brake and running lights in the rear. I took a 1968 Mustang GT500E to Germany with sequential lighting and TUV made me change everything.

Don't want to hijack the thread but Chris can't PM yet. Shoot me an email, it's in my profile.

Hey Chris where are you at in NorCal and where are you heading to in Germany? I drove my 54 Chevy Sedan over there in 2001 and TUV didn't make me modify anything. BUT, I was in the Army at the time. I take it you're not military if you had to deal with TUV? Or have they tightened up the rules?

Here is a link to some instructions of a 7 wire switch , it may give you some direction.
instructions on a box

Tim