39 Deluxe light wiring

[mhsprecher]

I have started to diagnose the problems with the lights on my 39 Deluxe sedan. When I started, only the parking lights and the left rear tail light would work but only on the parking setting and it was very dim.

I first taped up some bare wires running to the gas gauge and the left tail lights. No change.

The light switch had been replaced before I bought the car. I took it off and two of the wires were not connected. One was the horn, which blew constantly, so I taped it off. I connected the other one and the headlights would work, but would flicker after a while. Some crackling out of the area of the voltage regulator, which is not good. I will continue to diagnose.

Does anyone have a diagram of how the wires connect to the headlight switch? I have no idea if they are right. Given that two were not connected, there must have been a problem when they put the new switch on.

Boy, is that a pain to get to. Getting the bail back on was no picnic, either.

Thanks in advance for the help.

[JSeery]

Is this the wiring diagram you are using?

I upload a 33, 34 & 35 drawing of the light control switch plate for comparison. They were wired very similarity through the years, the 39 deluxe has the added foot dimmer switch which changes the wiring to the headlights.

There are 12 positions around the light control switch plate, three are not connected to anything and are the off position. The remaining 9 positions are in groups of three. The control rod from the column pivots a triangle shaped contact piece on these contact positions. The first set of three contacts are connected together with the power source so that there is power to the other groups of three for any position selected other than off. The brake lights are connected to this first group of three connectors and is always hot.

The second group of three contacts are also connected together and so have power in any position other than off. These contacts are connected to the taillights and the instrument & clocks lighting. This will be hot in any position other than off.

The third group of three contacts are NOT connected together and different individual contacts will be hot depending on the switch position. One position is connected to the parking lights, the center contact is not used and the remaining contact connects to the foot operated dimmer switch for the headlights. In the headlight position either the high or low beams will be on whenever this position is selected depending on the dimmer switch.

[mhsprecher]

Thanks, JS. The wiring diagram makes more sense now. I am a novice at this, so it will take a while. The brake lights don't work, either, which is what worries me most. I will not drive it until I get those fixed.

[JSeery]

Try a jumper across the brake light switch. The wiring to the brake light switch should be hot all the time, ignition switch on or off. That should tell you if it's the switch or the wiring. If there is not power to the brake switch something is messed up in the lighting control switch at the base of the column. The hot wire to the lighting control and the brake wiring should be right next to each other.

[mhsprecher]

I used a test light on the wires into the stop light switch. No juice on either one.

Boy it was hard to take photos of what I found, but here are the best I :






Here is my sketch of the switch:



When I first took the switch apart, two wires were not connected. The yellow and blue on the left and another I did not note at the time. If I connected the yellow and blue wire to the spare post, the horn honked all the time.

At the top of the sketch, both wires were yellow and black, but the one on the left hada small black stripe in it. The other was about 50/50 black and yellow. There were two wires that went into the female spade connector.

[JSeery]

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Here is a diagram I did up a while back. The spade connectors indicate it is an aftermarket part and harness. OK, the Yellow/Red is the power into the light switch, do you have power there? And the Green is the power from the lighting switch to the brake switch, if you have power on the Yellow/Red wire you should also have power on the Green wire. These both should be hot all the time.

With the steering column light switch in any position other than off you should have power to the Black wire which is the tail lights and a Black/Blue wire that does to the instrument lights dimmer control on the dash.

With the steering column light switch in the Parking Light position, in addition to the above, you should have power to the Black/Yellow wire to the parking lights.

With the steering column light switch in the Headlight position you should have the tail lights and instruments lights plus power on the Yellow/Black wire to the Foot Dimmer switch.

Update: My original post was an update from an earlier drawing I had done and had several errors in it (a hazard of working on the computer late at night after Thanksgiving!!!). It has been corrected to match the 39 deluxe car.

[Charlie Stephens]

This might help:
http://www.vanpeltsales.com/FH_web/F...ing1939dlx.jpg

Charlie Stephens

[mhsprecher]

As to the position of the headlight switch, Turned all the way to the left, the parking lights and one tail light was on. 1st click to right - nothing on - off position. 2nd click to right - headlights on. 3rd click - nothing.

My theory now is that instrument current was going to the one tail light that was on, although I'm not sure that makes much sense.

Looking at schematic you attached, it appears that the stop light wire (GR) and the power wire are reversed on my switch. When I tried to connect the BL/YL wire, the horn blew all the time. When I tried to honk the horn before I took the switch apart, it did not work.

In your drawing, you show the power wire and the instrument panel wire connected in the middle position of the three "connections." As you can see from my photo, the spade connections are to the outer two positions of the groups of three.

Your drawing also seems to indicate electrical connections at 9 of the 12 indents. My switch only has electrical connections at 6 of the 12 indents.

[JSeery]

Originally Posted by mhsprecher

As to the position of the headlight switch, Turned all the way to the left, the parking lights and one tail light was on. 1st click to right - nothing on - off position. 2nd click to right - headlights on. 3rd click - nothing.

My theory now is that instrument current was going to the one tail light that was on, although I'm not sure that makes much sense.

Looking at schematic you attached, it appears that the stop light wire (GR) and the power wire are reversed on my switch. When I tried to connect the BL/YL wire, the horn blew all the time. When I tried to honk the horn before I took the switch apart, it did not work.

In your drawing, you show the power wire and the instrument panel wire connected in the middle position of the three "connections." As you can see from my photo, the spade connections are to the outer two positions of the groups of three.

Your drawing also seems to indicate electrical connections at 9 of the 12 indents. My switch only has electrical connections at 6 of the 12 indents.

There were errors on the drawing I posted! You are correct, the Blue/Yellow wire is the horn wire (working to late at night I guess!!). I modified it from an earlier drawing I had done and it got hosed up in the process.

Within the groups of three it doesn't matter to which one of the connectors a wire is attached on the ones that are ganged together. So the power wire and the brake wire can be connect to either set of connectors (or together for that matter). Same goes for the instrument lights and tail light group. The ones that have to be on the correct terminals are the parking lights and the headlights.

Like I said before, your light switching plate is an aftermarket setup and not constructed like an original. I am not sure what an original 39 switch plate looks like I will try and find a photo of one, but most of the years looked very similar and just wired a little different through the years. I am posting a photo of what a typical plate looked like (this is NOT a 39 plate). The first two images are model A and the third one a 1937.

[JSeery]

I updated the original post in #6. It appears that there is a difference in the arrangement of the 39 car light control switch plate compared to all the other years. I have yet to find a good photo of an original one. The latest one I have an actual harness from is a 38 std. I attached a photo of an Early Ford repro of a 39 harness.

The horn blowing when the horn wire is attached means you have a short in the wire up the column or the horn button is stuck internally. The horn wire provides a ground to the horn relay.

[mhsprecher]

Then it appears that mine is connected properly. I can see where it does not matter which of the wires is connected to the groups of three. This is not really good news in that the fix is not in the switch wiring, unless there is something wrong with the design of the repro switch. It would not be the first time that has happened.

Next I will check to see if the wires you mentioned are hot. I have the battery disconnected while I am working on it, so I have not tested those, yet. There is clearly a short somewhere or I would not be having the problems I am having, unless the wrong switch has been installed, which seems unlikely. Most of the wiring seems new.

Thanks for the updated diagram, but that raises aother question. I only have 6 wires and I do not have a Blue/black wire.

[JSeery]

You can check the wiring by using jumpers at the light control plate. Get a short jumper with alligator clips at each end and connect one end of it to the hot (Yellow) wire. Then connect the other end to either the tail light group to check the tail lights and the dash lights (when you locate that wire) or to the parking light connector or the headlight foot switch wire. Remember, this jumper is hot at all times the battery is connected and if you have a short in a wire it can heat up fast! (as in almost instantly) Might start by connecting to the Yellow hot wire and just touching the other end to the other connectors to see what is going on. The problem may be open wires as well as possible shorted wires.

[mhsprecher]

I wonder whether I have the wrong light harness as there are only six wires? I did see where the blue/yellow wire connects to the horn contact in the center.

[rich b]

I think you have only six contacts and wires because a '39 deluxe should have a foot operated dimmer-switch.
I noticed you didn't mention the dimmer switch; but it would be the next step down the line to check once you get the headlight switch connections sorted out.

[JSeery]

Originally Posted by mhsprecher

I wonder whether I have the wrong light harness as there are only six wires? I did see where the blue/yellow wire connects to the horn contact in the center.

I just checked the standard vs deluxe wiring diagrams and there is not that much difference with the light control switch. The instrument panel lights goes straight to an on/off switch vs the dimmer switch on the deluxe, but it is the same color coded wire, Blue/Black. The other difference is one vs two tail lights, but again same connections at the switch and same color coding.

Can you locate the instrument lights on/off switch and dimmer on the dash? If so, what color wire is connected to them and where do they go?

[mhsprecher]

Latest installment. The light switch is back together. The horn works now and the lights pretty much work like they did before. Stop lights do not work. I noted, again, that when the headlights are on, they begin to flicker and I hear a crackling from under the dash. It is on the fuse block attached to the firewall. The fuse gets warm, too.

I noted that the fuse is a 12 v 30 amp fuse. Not original, for sure. To the right of the fuse, is a blue wire that goes to a variety of add-ons: turn signals, radio, heater fan and a fog light mounted on the front. I attach a copy of the diagram from the owner's manual that is quite helpful plus a few photos from under the dash.

I am assuming that there may be too much current draw from that new connection, which must be hot. I will use the test light to determine which is hot.

I have found the dash light dimmer switch, but not an on-off switch for the dash lights, if there is one.

The owner's manual has a wire going from the left of the fuse block "to starter switch through ammeter loop - Y" My car does not have this. What does that mean, if anything?

I have to say that these camera phones are so great for situations like this. I had to take a lot of photos from under the dash to come up with these, but pretty easy to do!

Next I will try and figure out what is up with the stop light switch, as I still have no current to it. The lights worry me, but I want to drive the car and I will not do it without brake lights. I will also try and figure out why the right tail light does not work. I may just disconnect the blue wire and see what effect that has on the lighting. FYI the turn signals work great, as does the radio. Well, it is an AM radio, but it comes on and makes noise. LOL.

I hope this thread is helping others. Many thanks to those who have commented, specifically JSeely.

[JSeery]

Are the turn signal light completely separate from the original tail lights? Also, are the grounds good on this car? Need to be sure the ground from the battery to the frame is connected to a clean part of the frame. Also need a ground to the engine and a ground from the engine to the body.

If it has the voltage regulator without the ground wire from the generator to the voltage regulator case, that can be an issue. 39 was the only year I think that didn't run that ground wire.

Need to make sure the headlights and tail lights have good grounds. Grounds can be the source of a lot of electrical problems.

[mhsprecher]

The ground was going to be the first thing I was going to check on, but you know how that goes.

The turn signals are wired through the tail lights. I will look at how they are wired, too. I did not see a ground from the generator to the VR, but I was not looking for that.

I spent the rest of the day raking leaves and waxing my Miata. Tomorrow back to the 39. Any thoughts on that 12v fuse?

[JSeery]

If the turn signals are using the same bulb in the tail lights as the brakes that could be the brake light issue. For that to happen the brakes are wired through the turn signal controller on the column.

[koates]

Hi there, No such thing as an automotive 12 volt fuse. The fuses are rated at only their current carrying capacity, which on your ford should be 20 amps ,not 30 amps. The ford headlight Bakelite switch plates changed in 1938 to the 6 contact type that is in your 39 ford for use with a floor dip switch. 1928 to 1937 had the 9 contact switch plate which incorporated the dip switch. One way for you to sort through your wiring problems is by using the correct 39 wiring diagram and follow each wire in the car from one end to the other and mark it off on the diagram as correct. This will take some hours but you need to check that each wire is routed and connected as it should be. Use an ohmmeter and a test light to sort through each wire. You should disconnect each wire from its terminations to test with your meter. My opinion is that rear indicator lights should be separate amber lamps and not using one of the stop lights. Better to always have two stop lights working especially when slowing down to do a turn. You don't want your pride and joy run up the arse by a distracted mobile phone user do you. Good luck, regards, Kevin.