12 volt relay's behaving strange

[Jeroensprint]

Hello, Englisch is not my native language but I will try to explain. I have made a reversing circuit with four relays for the pop-up headlights of my son's car. With it, he can make one light wink. It is a simple circuit what does work on paper. The schematic isn’t the problem or how to connect. Originally, when the lights are open, a constant voltage of 12 volts remains on a wire to the headlight motor, and when the lights are closed, that voltage drops and switches to another wire to the headlight motor so that the headlight closes again. This voltage switches back and forth via an original switch. With relays, I reverse these voltages for a headlight so that one headlight briefly receives its voltage in reverse, causing it to wink/open or close independently from the main system.

When I press my relays into the sockets, both lights start opening and closing uncontrollably without touching anything, and without there even being a switch or wiring in the socket to energize the relays. The relays do not click and, as mentioned, can never be energized from the outside because that wiring is not yet attached. There are four relays for one headlight that connect in the resting position. Connect all 30s to 87as in the resting position to maintain the original headlight control in normal driving conditions. If I simulate the relays in the resting position and create wiring loops and press these into the relay sockets between the 30s and 87as instead of the relays, the headlights work without problems.

I discovered that while measuring with the relays mounted, using a voltage tester with a light to see exactly what was happening, as soon as I hold a voltage tester against any wire (30 or 87a) in the socket, the circuit (connection in the resting position) works.

I tried a different brand of relay and also separated the sockets to create space between the relays, in case they were influencing each other in that way, but the result was the same.

The picture shows part of the circuit as it is now. With the relay this strange fault appears, and with the relay removed and bypassed with wire in the relay sockets (blue in the drawing), the normal original control works. Does anyone know what is going on here?

The problem is maintaining the car's ‘original wiring’: lights on, headlights up; lights off, headlights down, or via the external original pop-up headlight switch. If I connect the 'original wiring' via relays, I get this strange fault, but if I connect it in the socket with a wire loop, it works just fine.

Why does a relay in the resting state, with 30 and 87a internally connected, behave differently here than just a connecting wire in it’s place in the socket?

Kind regards, Jeroen

 

[Harald Kapp]

Show us the controlling circuit that drives the relay coils. Without knowing what drives the relays and how, we can't evaluate your circuit.

Also please explain in a bit more detail how the circuit is supposed to operate. Why do you put 2 relays in series?

 

[Jeroensprint]

There is none yet. I ran out of time last week and wanted my son to be able to drive his car. To have the lamps working again I needed to complete en 'reconnect' the original circuit again. So what is in my drawing is currently all what is in the relay sockets i'm using. But reconnecting through relay's isn't working but by loop wires it does. I never had such an issue before that a 5 pin relay in rest acts differently as a loop wire as technically it's the same. The relay's can't be driven and also don't click as there are no 85, 86 and 87 wires in the sockets yet.

Edit: 'koplampmotor' is headlight motor. The lower 'schakelaar' is the original popup switch that switches power inbetween up and down wires.

 

[Martaine2005]

Your theory is correct.
30 and 87a should be a closed contact just like your wire loop.
A spring in the relay holds the contacts closed.
I don’t understand this behaviour, there has to be something going on though.

Have you tried wiring the relays externally, away from the relay socket?.

 

[Jeroensprint]

Only the 30 and 87a are in the socket. Nothing else yet. I did disconnect the sockets from eachother to have the relais 'loose'. So not in a row anymore to check if these would interfere eachother but that didn't help.

 

[Jeroensprint]

Show us the controlling circuit that drives the relay coils. Without knowing what drives the relays and how, we can't evaluate your circuit.

Also please explain in a bit more detail how the circuit is supposed to operate. Why do you put 2 relays in series?

The two in series is that lower one will be disconnecting power when there is and the other upper opposite will be supplying power to have the up and down power wires 'switched'. There's four relay's in total to have it working both way's. Both lamps down and one winks open or when both lamps are up, one is winking closed. That's why its a double system. It's activated by a ground signal and the according relays will be powered by an up or down 12v supply so that when the lamps are up, only the 'down set of relais' have power and operate. And vice versa.

 

[ivak245]

I have had automotive relays which don't follow the standard terminal arrangement, but still plug into a standard relay socket.

 

[Jeroensprint]

There are two types of in layout in automotive relay's, type A and type B. Physically the same but as you say a different layout

 

[Harald Kapp]

There are two types of in layout in automotive relay's, type A and type B. Physically the same but as you say a different layout

And your wiring matches the layout of the relays you use, sure?

I don’t understand this behaviour, there has to be something going on though.

A very strange behavior, indeed.

A few ideas:

1. Try short-circuiting the relay coils so no current can pass through the coils.
2. How much power does the motor require? Maybe the relay contacts need a certain minimum current to work correctly (depends on the contact material). With a very small load the contact between the relay tongues may be insufficient and lead to a very high contact resistance. Your test with the voltage tester seems to indicate something along these lines. Try adding a small load (e.g. a lamp) at the output of the relay nearest to the motor (from output to ground) to increase the contact current.