Brake lights electrical problem.

Tiny
JBSS
  • MEMBER
  • 1961 FORD E-SERIES VAN
  • 3.3L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 999,999 MILES
Signal and brake lights were not working properly.

I found that the ground strap from the engine to the chassis was missing.

I added a new ground strap and now everything is working with the exception of:

1. Still no brake lights unless I engage the left turn signal. This occurs with the key on or off, and only the left rear lights up.

2. No left front turn lamp or dash indicator lamp, rear lamp is flashing fine. Rear stops flashing and goes solid bright when brake pedal engaged.

All running lights work, so all lights are getting a good ground, there are only 2 wires going to each light. The chassis serves as the ground.

If I run power to the left turn lamp directly the bulb lights up.

The flasher relay only has 2 wires and it is flashing properly for left and right.

I need help trying to figure out what is causing this problem.
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Sunday, March 2nd, 2014 AT 7:22 AM

14 Replies

Tiny
HMAC300
  • EXPERT
Thought I answered this one before but the bulb for dash may be burnt out. Make sure yo have a battery to body ground and it is good connection. Same with front light and see if power is going to front light. This may be a bad t/s switch.I have a diagram bu tit is off a car nd atruck is similar but find the brake light wire going to the t/s switch and see if power goes to the taillights which are gren and blue I think maybe yellow. Memory doesn't take meback that far. If it goes in but not out the t/s switch is bad then that may solve your light problem in rear but make sure the grounds are good back there and in front as well. Your wiring may be screwd up in thetruck as well due to age and people messing with it as well as rodents. They love wiring on a car. I do h ave another manual I can check but not sure how far back it goes but I think it has trucks which they all stayed the same pretty much until about 1970. Let me know if this has helped at all on your reply as it will come directly to me. Even though it goes on site.
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Sunday, March 2nd, 2014 AT 8:20 AM
Tiny
HMAC300
  • EXPERT
Forgot to send the pic sorry
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Sunday, March 2nd, 2014 AT 8:44 AM
Tiny
JBSS
  • MEMBER
Bulb in dash is good.
If I switch the bulb to another socket it works.

The battery is grounded to the engine block and there is a ground strap to the chassis. Running another ground from the battery to the chassis with a good connection did not change anything.

The front light gets power, but only to the running light circuit, the turn signal circuit is not getting power.

The turn signal switch is new. When putting a test light to the connection on the turn signal switch the test light will flash like a turn signal should so that has been eliminated as the issue.

Both rear lamps have running lights and turn signals. But the brake light only illuminates on the left side and only with the left turn signal on. This will also work with the key in the off position and the turn signal switch not getting power.

I can see the entire wiring harness and there is no rodent damage. Some of the harness is wrapped, but I do not want to start pulling it completely apart without knowing what I am doing first.

I have wiring harness diagrams, they do not help tell me what circuit is creating this issue. I believe this situation requires someone with excellent knowledge of electricity and how circuits work.

Something in the circuit is causing this issue and I am looking for help for the things I have not done yet, so here is my list:

Replaced: Flasher relay, turn signal switch 30 feet of bad wiring in the bed area, all the bulbs, 3 sockets, 4 lamp assemblies, head light switch, all fuses, battery cables, added a ground strap from the engine to the chassis.

My original problem was that I had no running lights, no turn signals, no dash lights, only head lamps and left rear brake light with turn signal engaged.

Doing the above repair/repalcements corrected everything except brake light and turn signal issue as stated above.
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Sunday, March 2nd, 2014 AT 9:42 AM
Tiny
JBSS
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I can send you the wiring diagram I have to study. It appears to me that the only place that the brake light and turn wires come together are at the connection to the turn signal switch. Maybe there is a short circuit that is feeding back in that area, but I do not know how to test this. Are you able to step by step help me test these circuits?

I have a test light and a volt meter.
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Sunday, March 2nd, 2014 AT 10:00 AM
Tiny
HMAC300
  • EXPERT
Send me the diagram as a pdf file at my email hmac3002@yahoo. The brake light sends power to the t/s switch which then sends down both lines to rear to activate the bulbs. You should have either a 1034 or 1157 bulb in rear for t/s and regular lights if not they are the wrong bulbs unless you have switched to led's Just because a switch is new doesn't mean it is any good. Just keep that in mind. On the older vehicles as I am assuming this is a 1961 like it says brake light should work all the time not with a t/s switch put in l/h position. If you are not getting power to the one light in front go back to wher ethe connection is made and see if it isany good like at the light as well as the firewall. The ip bulb may have a bad socket if bulb works in another or follow the wire back until you find where it does get power or it's a bad connection where it is connected. Just so you know I've been doing this for 50 years so it's not that hard and your test equipment is good. One thing though when useing a test light make sure it has an excellent ground like if you can send a ground to battery terminal and then to test light. That is why I said to check your grounds on lights as that is the most common cause of lights not working.
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Sunday, March 2nd, 2014 AT 10:14 AM
Tiny
JBSS
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I have the correct bulbs.

I tested the switch at the connections and it works fine for the turn signals.

Not sure where to hook to to test the brake lights.

The switch was NOS and they are not available any more, so if it turns out to be the problem I have to figure a work around or repair it. However the problem with the brake and turn lamp occurred with the old switch as well, so I doubt the problem is there.

The power is not reaching the connection at the front light. The problem lies somewhere else and the fact that the cluster indicator does not flash as well is part of the problem. I get the relay to activate and the rear lamp to flash, but that's it.

The ip socket checks out and is good.

What is really confusing to me is that I can swap the connections coming off of the t/s switch ( the ones supplying power to the lights) and either way I hook them up the t/s work the same. I am beginning to think I have the wrong t/s switch, but that does not make sense because it looks identical to the old one and gives me the same problems.. Of course maybe the old one was wrong also.
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Sunday, March 2nd, 2014 AT 11:24 AM
Tiny
HMAC300
  • EXPERT
The green/whit wire supplies to the left front as well as dash so it has to be a connection if it is coming from the t/s switch. Are you absolutely sure you do not have the wrong bulbs int eh lights? If the lights are getting power from the swtich it is one of two things the wire leading to the lights that aren't working is either broken or shorting to frame or the ground is bad like putting a ground wire to the body. I dont' remember if the evans were unibody or frame if they are frame they need a ground to body as well.
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Sunday, March 2nd, 2014 AT 11:39 AM
Tiny
JBSS
  • MEMBER
From your email: "Ok you don't or shouldn't need the ignition on for the brake light test. Take your test light and probe the red/blk wire gong to the t/s switch for power. If it has that then probe the green and yellow wires for power they both should have that with brake pedal applied. If no power then it's a t/s switch problem of some kind. Then probe the green/white wire that is for your dash light and front parking light. If power there then pull the cluster and probe by bulb to see if it is getting power if it does then it may be a bad bulb connection which the interior guts can be replaced without the whole base. Power will be needed for those two. Then probe green white wire near front turn signal see if gets power. If it does then it may be a bad socket which are also available at auto parts. You just need the guts. The bulbs should either be a 1034 or 1157 with two filaments for front and back t/s lights. The corresponding wires in rear will be yellow and green for the sides the brown wire in back is for taillights, etc. Let me know what you find. Make sure the bulbs are the ones I've said in front and back because this can cause problems as well if the wrong ones installed. "

I tested the red wire to the brake light switch and it has constant power.
The red/back runs from the other side of the brake light switch to the t/s for power.
With the brake pedal depressed the red/black has power going into the t/s switch.
No power comes out of the t/s from the green or yellow wire.
When I engage the left t/s the yellow wire has power, but nothing still from the green in any position.
I put direct power to the yellow and green wire in the harness and I get illumination on both rear brake lights.
I put a jumper from the red/black wire to the yellow and green wires and I get illumination on both rear brake lights.
So it appears that the $150.00 NOS switch I purchased from eBay last November is crap?
I would like to take a look inside of the switch and the cam assembly is a still available serviceable part, but I cannot figure out how to remove the retainer from the pin holding it on.
This does not seem to be too complicated a device and I think my only option is to disassemble and repair it. Your thoughts?
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Sunday, March 2nd, 2014 AT 1:22 PM
Tiny
HMAC300
  • EXPERT
I kind of figured it was the t/s switch. If you bought n ebay was it from some type of dealer or just some guy selling parts. You can take it apart and try to fix it but i'd bet ther eis apiece missing like a metal link they are not complicated, it may be just something bent out of shape as well. All you can do is try it and be careful on disassembly and not in ahurry it would be better to try to fix this thing out of the column. I have no idea on how to take it apart as it has been years since I've done anything like that and I think if I am correct the cam assembly is only for the switch to return to neutral position and hasn't anything to do with power. If you could send me a pic once it's out to my email instead of here I may be able to jog my memory enough to help with it. You already have that address and I think ifyou click on my name it gives it anyhow. Good luck. You might try one of the Ford parts placesas one out of a car may be the same just wire length may be different if things go really bad with this one.
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Sunday, March 2nd, 2014 AT 2:03 PM
Tiny
JBSS
  • MEMBER
I got the can off. Everything looks fine in there. I am suspecting that the wires are in the wrong place and I need to find a schematic showing what color wire is supposed to go where in the switch.
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Sunday, March 2nd, 2014 AT 3:01 PM
Tiny
HMAC300
  • EXPERT
You have that in your diagram alreadypull the switch down for lh and it should touch where green and grn/wht connect. I still think there is something missing in switch.
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Sunday, March 2nd, 2014 AT 4:01 PM
Tiny
JBSS
  • MEMBER
I solved the problem. Thank you for leading me to the t/s switch.

There were two issues that came from it being assembled wrong.

1. The small actuators in the switch were installed upside down and backwards, so they were making the wrong connections when the switch was activated and were feeding power to the wrong circuits.

2. Two of the wires were switched and going to the wrong plugs.

I had to rebuild the switch so the actuators were installed correctly, and cut the plugs off and go through each circuit one by one to determine proper placement to where they were supposed to go in the trucks harness (since the wire colors were useless at this point due to the manufacturing defect.).

Once I did that I was able to troubleshoot and correct the placement of the two reversed wires, reconnect the plugs in the proper order and heat shrink the junctions. Now everything works the way it should have when it was originally built.

The irony to all of this is that the likely reason this part was still available was because it had been returned as defective and the dealer just put it back in inventory.

The fact that this part has been discontinued left me with no choice but to correct the manufacturing errors.
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Sunday, March 9th, 2014 AT 9:37 AM
Tiny
HMAC300
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Well it wasn't probably manufactured by ford anyhow and that is why it is/was screwed up to begin with. Least it 's fixed now.
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Sunday, March 9th, 2014 AT 11:05 AM
Tiny
JBSS
  • MEMBER
It was a genuine Ford part. However I know they use outside vendors. This particular part is not available after market. I bought it out of new old stock from a ford Dealer.
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Monday, March 10th, 2014 AT 2:03 PM

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