VCCA Home Forums TECHNICAL - GENERAL Electrical - 12 volt Wiring tail lights and turn signals

I'm getting ready to add a right rear tail light and turn signals to a '37 half ton. I bought a turn signal switch/lever (TS) and univeral flasher relay (Trico). The truck was converted to 12v by a previous owner. I don't have the wiring diagram or know the brand. The TS wiring diagram is confusing me. I think I have traced and labeled all the harness wires needed for this project. Before I do any splicing and connecting I want to walk thru the project to make sure I understand what I'll be doing. I know little about this.

The flasher diagram shows different labels on its three prongs than are shown in the TS diagram, with the exception of prongs labeled "L". Does it matter which prongs are connected?

The TS diagram shows "cut & tape" splices. Wouldn't it be better to use crimp-type connectors?

I suggest keeping the turn signal wiring and lamps completely separate from the truck wiring so you don't have to cut and splice into the main system. Right or left is determined by the switch so the other two flasher terminals should be + and the indicator lamp.

Crimped terminals are ok, barrier strips or soldered terminals are better.

Thanks for the info.

I think the standard 3 prong flasher has:


X = power in
L =lamps (left or right to be determined by the switch lever)
P = Pilot lamp indicator

if you have left and right indicators there is a trick to make them work properly. look on the 1953 schematic diagram to see how it works.

MrMack:
Thanks for the info. I downloaded a "53 wiring diagram from Ken Hardy's site. I spent time last evening reviewing the diagram and will need more time on that. I didn't realize that Chevy trucks even in 53 only had one rear tail light. Is the "trick" you mentioned in the diagram somewhere?

I'm making these additions now because of two recent tailgating incidents that came near resulting in the need for body work. Seems some "adults" and a few young drivers don't understand or recognize hand signals, but many seem to know the middle extended digit gesture and they use it freely.

I would be wiring the turn signals to a separate amber lens light to comply with current requirements to avoid confusion and any more near tailgate incidents. I am sure there are aftermaeket lights that look similar to the tailight already on the car. Also much easier to wire up.
Tony

Yes If you look closely you will find that each indicator bulb has two leads, neither of the leads are connected to ground.

One lead of the RIGHT turn indicator is connected to P on the flasher plug, the other lead of the RIGHT turn indicator is connected to the lead going to the LEFT front turn signal lead

One of the LEFT turn signal indicator leads also connects to P on the flasher plug and the other lead on the LEFT turn indicator bulb is connected to the lead going to the RIGHT front turn signal lead.

Both indicator bulbs receive flashing voltage from P.

This hookup lets the voltage from the turn signal that is powered to go to the opposite turn signal indicator, that way when you have six volts on both leads of an indicator the light does not burn.

The indicator bulb that is on the side the turn signal is switched to will ground thru the filiment in the front turn bulb not receiving power and only that indicator bulb will burn.

Neat.... Eh?

Thanks again. I'm headed out to the shop now to start the work.

You are welcome Leon.......

Mack:
The lights are all wired and working fine. I'll be real careful next time before buying after market parts. The switch was made in China and I think the instructions were translated into a bunch of other languages before english. They were as clear as mud and the wiring diagram too was inaccurate and incomplete. That all added to a neophytes learning curve made for lots fun.