Turn Signal Problem/Location of dist. box

[dimcc]

My turn signals were working fine; I wired up a cable with a couple of relays to interface with a 12v trailer; in the midst of hooking things up the turn signals stopped working. Stopped working even with the cable disconnected.

Most of the posts I see about signal problems make reference to checking ground and power at the distribution box, that makes sense, but....I must be simple-minded or blind. Where is the distribution box?

My truck was delivered 4-68; Mfr model 3521, Mfr serial 21631

Someone point me in the right direction, please.

[brute4c]

On the firewall next to the brake master cylinder, on a stock truck, you will have either a distribution box:





Or a solid state flasher unit:

[Barrman]

If you have the solid state box. 1 stray electron and it will be shorted out completely.

[militarypotts]

I have a solid state box in my truck. My turn signals and emergency flashers work when they want to. Looked into steering column box, it appears brand new. Put in new 24 volt bulb from NAPA. Sometimes the indicator light barely flickers, other times it comes on and stays lit continuosly. Other times the bulb stays lit for awhile, and then starts to blink. Drives me crazy. I have a new solid state box, just never installed it because I'm not sure it's the problem. Sounds like a bad or loose ground problem, but where? I've tightened the solid state box down to the firewall. Sure wish I could depend on them more often. HELP!

[Barrman]

Hmm, I sure thought I made a sticky out of how to check the solid state box. Can't find it. Oh well, here is how you check the box:

Pin “A” to a light bulb which is grounded

Pin”B” to a 24VDC source

Pin “C” to ground

When “B” is connected, the light should blink about 80 times.minute

[dimcc]

Thank you folks for telling me what that thing on the firewall is....I'd been wondering.

I'll clean some contacts, try the test sequence & see if it really is fried.

If it really is fried, has anyone tried substituting a pair of 12v flasher units in series?

[Barrman]

The 3 lever switch, blinker arm switch and flasher box all work together to allow service lights, service brake lights, b/o lights and b/o brake lights. Plus service blinkers. Sure, you can do a work around.

However, nobody here or anywhere else is going to be able to offer help to you on exactly how to do it or repair it. Sure, we can take a guess. but, it will be a system you engineered and only you will have experience working on it.

Look through the online manual section at the top of this page. The Lighting wiring diagram shows you all you have to do for all electronics on the truck to work. I think it is an elegant, simple and time proven system that really doesn't need to be messed with. Especially, since you can buy every part of the system from any computer in the world and have it at your door in a day or two.
The -20 and -34 manuals also talk you through how to work on the system.

[dimcc]

I see the wisdom and appreciate the courtesy of your response. Thanks.

[MJCougler]

Team,

Is this a good place to ask about "parking lights" on our truck? Is there a way to turn on the "turn-signal" lights as "parking lights"? As with late model cars, when you turn on the headlights, the first click is the "parking lights". I have not figured out if our solid-state turn signals will operate this way? Any ideas?

Thanks in advance,

[Barrman]

This is going to sound mean, but you guys really need to read the -10 manual. It is like the owners manual of a civilian car explaining how everything works.

The bottom left lever on the 3 lever switch turns on your dash lights to "dim" or "bright". It has an "off" position and a "park" position as well. With the service lights on, "Park" gives you what most people call running lights.

This is a very handy feature when driving slower than traffic and somebody with a trailer passes you. I know, we always keep up with traffic. But, for those rare times when we get passed. Just use that lever to flash your headlights once the trailer is clear. Sure beats having to lock and unlock the main lever. You do drive your hard to see shade of green truck with the lights on in the day, right?