Another odd project - F350 with a big-truck turn-signal switch

Whenever i need a diagram his supermotors is my first stop!

I had it bookmarked a while back, dunno how I lost it...

On the wiring thing, from what I can see the Signal-Stat needs a 3-prong flasher, while the Ford wiring uses two 2-prong flashers. The only difference I found between the two is that the extra prong is used to power indicator lights, such as those on the SS itself, however our indicator lights are powered through the front blinkers, meaning I could probably use the factory 2-prong flasher if I can live without the indicator lights on the SS working... The only thing is since the SS does the 4-way thing internally, there's no longer need for the factory flasher - is that assumption correct? Also, in my experience the two factory flashers are identical and interchangeable, so what was the reason for having both of them when just one would do the job - so they can power the directionals key-on, and the hazards constant-hot, in other words so blinkers only work with the ignition on but hazards work always?

If this switch only has 4 wires, it must be a model 902 or 903. It's just a simple switch, red for the left turns, green for the right turns. I believe the other wires are for the flasher unit, and a single dash indicator(which you do not need).

If you have a wiring diagram for your truck, you need to intercept the incoming stock flasher wire and feed the new switch. Find the front left and front right turn wires, and wire them to the new switch. This will also take care of the dash indicators, they are fed off the front turn wiring.

The problem comes with the rear wiring. As you already know, the rear lights do both the job of turn and braking indicators. On the stock switch, the brake signal from the pedal switch enters the turnsignal switch.

What I did in this exact situation when I was wiring a 53 f100 and adding turnsignals, is go to the store and buy a trailer tow adapter box. It was about $12 10 years ago. What it does it take a vehicle with separate amber turnsignals and red brake lights, and combines these functions together electronically so you can wire the vehicle to a regular trailer with single red combined lights.

It's a little black box with wires coming out, and I mounted it under the dash. You wire the left turn and the right turn wires from the turnsignal switch into the box. You also wire in the brake pedal switch signal wire. It takes these 3 inputs, and gives you two regular combined output wires that you can then run and tie into the two wires feeding the rear lights.

It's a little black box with wires coming out, and I mounted it under the dash. You wire the left turn and the right turn wires from the turnsignal switch into the box. You also wire in the brake pedal switch signal wire. It takes these 3 inputs, and gives you two regular combined output wires that you can then run and tie into the two wires feeding the rear lights.

PM me your addy, I don't know where here and there is.. I have some left over from the RV business, free, just $5 for ship.

LCAM-01XA said:

Hey folks, I have a Signal-Stat 900 SigFlare switch from a Mack truck that I'd like to install in my '90 dually. How would I go about wiring this up? It has four wires: blue, red, green and yellow. I assume yellow and green wires are for the left and right turn signals respectively, so of the remaining blue and red one is power and the other is likely for the hazards. But that's only four wires, whereas the factory turn-signal switch has a 10-pin connector - now I know of these 10 pins two are used by the steering wheel slip rings (for cruise and horn) and one is for the wire that grounds on the ignition key tumbler, so these I will not mess with and leave as is, however what about the remaining 7 wires? I was suggested that I may have to run separate turn signals and brake lights (not combined as they are from the factory), however the Mack truck the switch came from had only two lights on in the rear so they must have been combined park.brake/turn lights like our pickups have... Any ideas and/or suggestions?

Click to expand...

There are two Signal Stat set-ups, a 7-wire and a 4-wire.

I am almost 100% certain that I used the 7-wire on my 1985 F-350 that has been on there for over twenty years.

It is hard for me to have a favorite modification, as I can't imagine having to do without any of them; but, suffice it to say that, were I to have to replace my truck with another, installing one of those Signal Stat switches would be among the very first projects; I LOVE IT

May I ask why?

I have the original box and instructions somewhere on this 7-acres; I will eventually find it.


YES, these switches use a single 3-PRONG flasher.

Think of the switch as a plain old SPDT toggle with a long handle.

Center is OFF.

UP switches power to the RIGHT side.

DOWN switches power to the LEFT side.

Pulling outward on the little chrome handle-thingie underneath the lever powers BOTH sides.


These signals have ABSOLUTELY NO BEARING on whether the vehicle has independent brake-lights or just plain old single-bulb brake/signal lights.


You can, with some head-scratching, use this 4-wire controller, it is just not going to be so direct as using a 7-wire.


The choice of whichever one used has no bearing whatsover on the little indicator lights in the dash.



Some have asked "why on earth would I want this ??"


For starters, I always preferred NON-CANCELLING signals for a number of reasons.

The fact that the factory switch in the column caught on FIRE and burned/melted everything into oblivion gave me the incentive to go ahead and make the swap.

I made my living long-hauling livestock for years.

Being used to big trucks, it annoyed me to no end to be in the middle of a turning maneuver and have to constantly keep flipping that stupid useless self-cancelling switch back to the TURN mode.


Also, for numerous reasons, it is desirable to have the ability to leave a signal ON with the KEY=OFF and in my pocket; those that actually drive trucks will understand this so I won't try to explain to those that don't.


The factory switch is barely capable to carry the juice for the simple factory signalling set-up; hang into a big trailer with a bunch of signals, along with a steel flat with numerous signals, plus extra ones on the mirrors, and that wimpy factory mess ain't gonna like it long.


The Signal-Stat lets you stack lights chin-deep and keeps on going strong.




I really like the look and lay-out of the classic 1985 dash and instrument-panel; the next and latter styles just don't quite cut it for me.

That being said, two little aggravations exist with that style of dash; the signal indicators and BRITE indicator are back inside little tunnels and are not easily seen.


I hated this for years and finally did something about it a few years ago.

I routed wires from each side of the system, BEFORE the brake-light over-rides the flash, to big AMBER indicator lights located each side of my 3-gauge pod that sits atop the dash, sort of angled toward me and above the radio.

These indicators are WAY EASIER to see and much more noticable.

Plans are in the making to add two more BIG ones; probably one each top-corner of the windshield.


I will continue my search for the actual instructions.

And for those that are curious, I also added a separate BRITE and a REVERSE indicator in that gauge pod = MUCH BETTER.

/\ mamma was from Mizurah... show me?

(humble request for pics sir...)

Okay; original twenty-some-odd year old box and instruction sheet is in front of my eyes.

DISCLAIMER:

If someone's truck burns to the ground or melts into oblivion, I take no responsibility for the following; proceed with educated caution and a clear view.

Looking at the terminal end of the flasher, three terminals, one at 9-O'Clock, one at 3-O'Clock, and the center at 12-O'Clock.

9-O'Clock is fused HOT.

3-O'Clock is LOAD, which should be YELLOW.

12-O'Clock is PILOT, which should be BLUE.

The GREEN wire should connect to the FRONT LEFT signal wire.

The RED wire should connect to the FRONT RIGHT signal wire.

The factory switch should be dis-connected/un-plugged at the column and this should render the factory flashers dormant.


Is that MACK where you can look under the dash and behind the driver seat ??

Just about all wiring should connect at a couple very long terminal strips, with any relays and associated goodies in the near vicinity.

Taking a good look at that should help understand just what goes where.



On the box, I have a crude drawing of what I think may be the factory plug at the column; it has been many years and I am not certain.

Large YELLOW wire with BLUE DOTS = HOT.

BEIGE wire with RED SPIRAL DOTS = ??? maybe KEY=ON=HOT but not certain.

GREEN wire with a RED STRIPE = LEFT BRAKE LIGHT.

ORANGE wire with a BLUE STRIPE = RIGHT BRAKE LIGHT.

LIGHT BLUE wire = TURN SIGNAL FLASHER.

GREEN wire = BRAKE PEDAL SWITCH.

BLACK wire = ??? maybe HAZARD FLASHER but not certain.

GREEN wire with a WHITE STRIPE = LEFT FRONT SIGNAL.

WHITE wire with a BLUE STRIPE = RIGHT FRONT SIGNAL.

DARK BLUE = HORN.

UNKNOWN COLOR wire = badly faded and can't make out what it says.


If this 4-wire controller will not work on our model of trucks, then your money will be better spent buying a proper 7-wire controller, than buying an electronic gizmo to make it work.

Look around big truck junk-yards and swap-meets and you should find plenty of 7-wire controllers for cheap.

I see lots of them at swap-meets.


ALSO, I just remembered, these controllers assume a GROUND via being firmly strapped to the column; the problem is that the outer coverings of our columns are isolated from GROUND.

To get the little indicator lights that are made in the controller to work, I had to add a GROUND wire to the clamp-strap.


If you opt for the 7-wire, I have the diagram for that also.

>>> MORE INFO <<<

The strap that comes with these switches assumes a slim big-truck-style column, without all the fatness necesary to house all the car-like foolishness that should not be contained within a column.

That strap is going to need to be lengthened.

I accomplished this ( ?? I think ?? )by pop-rivetting a length of plumber's strapping to the two end points of the supplied strap.

I will try to remember to actually look at mine tomorrow.


The instructions state that these units are capable of 6-, 12-, and 24-volt service, with only the little indicator bulb needing changed to accomodate the different voltages.

It also states that it will carry TWENTY 1157-style lamps per side when used with a PETERSON #577 flasher.

Wow, that's a lot of info there guys! Thanks for all tho, your efforts are much appreciated. So maybe I do have a 902 or 903 switch then, and what I found on the net for wiring diagrams does suggest it too, but it does say 900 on it... The trailer lights box setup I ain't too crazy about, I'm sure it works good but I'm trying to simplify the factory mess or at least make it a bit more reliable, so for the time being I think I'll look for a 7-wire Signal-Stat - plenty of big trucks in that junkyard, something's gotta have what I need. If I'm not successful in that, one of Old Bull's RV boxes it will be On the grounding matter, I cannot even strap one of these around my steering column due to how the dash panels are positioned - what I can do however is make a nice steel bracket for it that bolts to the steering column support brace, using the same two bolts that currently hold the bracket for my hand-throttle setup as well - there is enough gap between one of the panels and the column to where I can bring that bracket out from under the dash and then bolt up the switch to it - I got a welder, fabricating stuff like that is actually somewhat of a hobby of mine.

cut youre turn wires before stock plug and splice in is what id do
my cam broke too dont auto return i never forget but anyone else who drives the truck usually does thankfully thats very rare '

personaly i like it make 3 right turns in a row keep it on