Mal funktion brake switch

[Werner]

Guten Abend,

I have a problem: the brake light only works when the turn signal is switched to the left or right at the same time. If there is no flashing, there is no brake light possible. Does anyone know this problem?

Thank you in advance for any help.

[Ruth]

The first thing I always check when electrical is acting up is GROUNDS. Those little electron guys do weird things if the can't find the correct path home.

[rotorwrench]

Add on turn signals vary in quality and function. The brake light function has to be connected in to the signal switch to separate the two functions. It is the only way to have both brake and signal. Does your unit have 4 wires or is it a seven wire signal unit?

When left turn is selected, the signal stat will only function the left brake light part of the tail lamp to flash since the brake light function is isolated by the turn switch. The right side will only have the brake light function when the brake pedal is pushed. All is the same with right signal selection (equal but opposite). If it is not working in this way then there may be a problem with ground path as was mentioned or something is not working correctly with the turn switch function.

Brake lights should function normally if no turn signal is selected.

[Werner]

Hallo und guten Tag!


Thank you, I understood now that the brake switch deal funktion is in the flashing switch. It is one with 6 connections.


(Ground connections are all good, I grounded at least 5 feet of copper braid stripes all around.)

[Will N]

Check your wiring. I don't know what brand turn signal kit you have, but I am attaching the wiring diagram for the one that I have, it's a Trucklite 900. Yours can't be too different. The output from the brake switch is rerouted from the original path (directly to the brake light bulbs,) and instead it goes to the turn signal switch via (in this case) a black/gray wire. The input to the brake light switch needs to be left in place, which is not made clear in the diagram. There needs to be two wires going out of the turn signal switch back to the rear brake lights- one for the right, one for the left. Same for the front lights (if you have them). In operation, if you are using the turn signals, the power feeds through a new lead you need to connect to the ammeter (I actually wired it to a junction box post) through the fuse, through the flasher through the switch to either the right or left bulb. If you step on the brake, the power is fed through a different path. It comes from the original input to the brake switch, out and up to the turn signal switch, and out through both the right and left wires to the rear brake lamps simultaneously, bypassing the flasher circuit altogether.

[Werner]

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Guten Abend!
Correction: there are 7 cables! -

Thanks for the helpin' schematic. The fault is actually in the turn signal switch, which does not redirect the current flow to the brake lights in neutral position. I cleaned the contacts, but that didn't help.

Tomorrow I will disassemble the entire turn signal housing deep down. I'll report!

[Werner]

Hallo und guten Abend.

I solved the brake light problem. The turn signal switch is of very poor quality. The lower contact tongues are much too thin and did not have good sliding contact. I bent the contacts a bit. And put a washer on the shaft to increase the contact pressure.

But this is only a short success, I will look for a better quality switch.

Thanks at all for the helpful advice. Here in Germany the combined function of brake light + rear light is unknown.

[Y-Blockhead]

Originally Posted by Werner

Here in Germany the combined function of brake light + rear light is unknown.

Werner, since it is not common in Germany to have them combined, maybe it would be better for you to separate them. I may be better for the other drivers also.

Hereis a picture of mine rear turn indicators, they look somewhat period correct? They have RED LEDs in it.

What are you using for turn indicators on the front?

[abachman3]

Motorcycle shops have a good selection of various lights that work well for turn signals.

[Werner]

No, I want to hold the original as the car was operated in the USA. In the front I have converted the additional lamps to flashing lights.