MK178 problem

Not sure if I have a problem or not . I have just built a MK178 brake light flasher kit, but the SK4 socket may or may not be working.

From my understanding if the SK4 socket should

A> If it does not have a jumper on it, it should only pulse the light after 7 seconds of the previous application of the brakes. Though if you press the brakes in that period the 3rd brake light should just operate as it would without the kit installed.

B>If SK4 is jumpered the 3rd brake light should pulse even if the brakes are operated within 7 seconds

The unit I have only seems to do A>

Your understanding is correct.
Seems like the µcontroller is not working. In that case, the unit will behave like it is not there.
Check supply to µcontroller. Check that controller is correctly inserted.

Hi thanks for your reply. I have reseated the 8 leg chip into the holder in case it wasn’t seated right, and it the unit will only pulse after 7 seconds.
Where should I check the supply to the chip/controller and what voltage should I see.

GND: pin 7
+5V: pin 2

OK I’m seeing the required +5v on pin 2 when the brake is operated, but still no change to function

Check what happens on pin3. Should pulse when brake is pressed.
If not, PIC probably defective.
In that case, return PIC to:

Velleman Kit Tech Dept.
Legen Heirweg 33
9890 Gavere

OK with the jumper on or off SK4, I see a steady +5v on pin 3 when the brake pedal is pressed, but no pulsing occurs. The small red LED also stay red with no pulsing.

This I guess means returning the PIC to you from the UK for replacement.

Do I need to quote a reference number, so whoever receives it knows why it is being returned


Make sure to mention the kit number.
If the PIC is defective, we do not have the means to detect from which kit it came.

Thanks for the help so far, the PIC is now sent in the post to you

Hi Thanks for the sending a me a new PIC, seem to have a new problem though. The main 12v track has fused burning itself from the circuit board. I would email a photo but lost your email address

Definately because of a short circuit at the other end.
Please have your assembly checked by someone with experience before attempting to power it again.

Managed to work out what caused the short, and repair the circuit track on the circuit board. The wiring that came out of the circuit board had shorted out between +12v and 0v. It occured as the circuit board is secured to to the inside of the bodyshell of the car , but the 3rd brake light is in the boot/trunk lid. There was more than expected movement in wires that ran between the light and the circuit board, when you open the boot lid, this movement frayed the wires. Secured it more sucessfully now

Morning Guys,

My buddies and I have recently bought some of these kits, but the boards that arrived in the kits are marked PMK180’1 instead of the PMK178’1 that is on each box and was ordered.

Is this the right board, as we have another 2 kits on the way.

PMK180 is for a different project.
This problem has not been reported yet.
Sorry for the inconvenience.
Please let us know how many MK178 boards you require and please supply an address.

[quote=“VEL417”]PMK180 is for a different project.
This problem has not been reported yet.
Sorry for the inconvenience.
Please let us know how many MK178 boards you require and please supply an address.[/quote]

I have some photo’s that I will post. It seems that it wasn’t just the board, the components are incorrect too. Seems like they were put in the incorrect packaging. The IC doesn’t correspond to the kit either, and the LED’s are the incorrect colour.

The components and the pcb form the complete kit of the MK180.

In that case, please return everything to your distributor for exchange.
Sorry for the inconvenience. We have checked our warehouse and all items on stock are correct.

Thanks for your help.

We will return the kits and let you know once we have the correct kit and built it up.

Thank you once again.


I have fitted two of these units on both of my cars and changed the brake lamps to ultra bright LEDs, they work great but I would like to slowdown the flash rate a bit.
Can someone tell me which component controls the flash rate and what can I replace it with to get it to flash slower.

Many Thanks


As far as I remember this kit, this is not possible: timing happens inside the microcontroller (IC) and that runs on its internal clock. Unless Velleman has some easter eggs incorporated which I do not know of ;).

Sorry, no easter eggs at this time.
Timing is determined in the firmware.