Instruction for relays

Nabsim

Nabsim

Full Member
Posts
4,799
Likes
5,917
I am in need of some sites to learn about relays. Have only really used them for things like horns, spotlights etc in the past but have decided to sort out my electric step.

I know how they say to wire the step but that doesn’t fit with the way the van is wired so I need some resources to look through. Preferably not too advanced as I can be lo eating my head round things initially.
 
Nabsim said:
I am in need of some sites to learn about relays. Have only really used them for things like horns, spotlights etc in the past but have decided to sort out my electric step.

I know how they say to wire the step but that doesn’t fit with the way the van is wired so I need some resources to look through. Preferably not too advanced as I can be lo eating my head round things initially.
Click to expand...
This is (IMO) an interesting and informative article about relays, and includes some pretty cool uses of them (I especially like the one with the hidden ignition cutout circuit. very clever)

Automotive Relay Guide | 12 Volt Planet

Read our guide to relays found in vehicle electrical systems. How they work, why they're used and some example applications.
www.12voltplanet.co.uk
 
I am struggling to put into words what it is I need as I haven’t been able to get my head round it so far. I have looked at 12v planet info and that is stuff I already know (mainly) so maybe it’s not how relays work but more application of them I am after.

Spent hours today tracing wires, dismantling switches etc to find out exactly what I have. I now know what is there but not how to get it working.

Originally my van has a Toptronic unit that allowed remote control of step, patio light and main living are light. Because of the remote they ended up with the control unit with 3 relays soldered on the board. I can rewire the lights okay as I no longer need a relay for them but to get the step to close when I turn the key I will need a relay or more than one. That’s the bit I want to read up on although it may be that it’s unique to my van
 
Nabsim said:
I am struggling to put into words what it is I need as I haven’t been able to get my head round it so far. I have looked at 12v planet info and that is stuff I already know (mainly) so maybe it’s not how relays work but more application of them I am after.

Spent hours today tracing wires, dismantling switches etc to find out exactly what I have. I now know what is there but not how to get it working.

Originally my van has a Toptronic unit that allowed remote control of step, patio light and main living are light. Because of the remote they ended up with the control unit with 3 relays soldered on the board. I can rewire the lights okay as I no longer need a relay for them but to get the step to close when I turn the key I will need a relay or more than one. That’s the bit I want to read up on although it may be that it’s unique to my van
Click to expand...
Have you drawn out a schematic of what is connected to what? and under what circumstances the different things 'happen'?
I find looking at that kind of thing helps understand how to adapt.
 
That’s what I am struggling with, can’t figure out how it would have originally worked.

The 2 part (left button out, right button in) has 3 cables going to it, I now know one is +12v and then it passes 12v to whichever side button is pressed. The step motor has four cables for in and out, 12v D+ and negative/ground. Presumably the +12v to the switch needs to be live and the other two cables from the switch (in and out) need to go to the relay.

It’s strange as all switches are 240v 16a and the cable is heavier everywhere than the original motor cables. No negatives on any switches, totally different from anything I have seen before. I know it’s probably straightforward once you get your head round it but after about 5 hours today all I have done is identify what’s what, no closer to how it goes.

Not even sure if I should be looking at 5 pin relays with the way the step switch is wired, maybe need to split off in and out aacross two 4 pin relays
 
Why not google 'motorhome step relay switch' and see what turns up. There may even be a wiring diagram. I think they are not exactly a normal relay as they operate a motor in 2 directions (forward/reverse).
 
maingate said:
Why not google 'motorhome step relay switch' and see what turns up. There may even be a wiring diagram. I think they are not exactly a normal relay as they operate a motor in 2 directions (forward/reverse).
Click to expand...
I have a few of those but not found anything that would apply to what I have in.

Thinking I may get new switches and wire it without a relay so it’s back on electric step then fit a relay at a later date. My switches don’t allow for +12 and -12v which is what I see in all the diagrams for electric steps so far
 
DTF said:
Is this description any help.

Clive`s

www.motts.org
Click to expand...
It has helped in the fact I didn’t realise reversing polarity changed the step from in to out to in etc. the switches fitted don’t take both positive and negative so it won’t help in getting it running as is. It will help if I do change switches though 👍
 
Does your step switch have a "out" and an "in" position? I think if it does, it should be quite straightforward? Asking this as, for example, my step (a "Thule" one which may or may not be relevant) only has one switch, which is a momentry switch and if the step is in, it goes out, and if it is already out, it goes in. That would be quite a different circuit to work with in terms of control and likely more awkward?

And ... I would think it should be possible, if need be, to entirely bypass the existing control circuitry, bypassing it and sending the relevent power/control direct to the step motor to make it go in and out.
 
Nabsim I am in the process of fitting a Thule sliding step.
you can find instruction on line quite easily.
mine has a switch that is in or out and simply reverses polarity So plus/ minus in from battery (20amp fuse ). Plus/minus out to step.
of you want to have a warning buzzer then connect the two thin wires to earth and a buzzer with connect to a switched live. This is what I have done.

if you want auto closer it needs a special relay from Thule


good luck
 
Oh for the love of a self build. 😂
vs16.jpg
 
Neil,
What step do you have?
How many cables come from the step?
Has it ever worked in the way you wish it to work? (basically has it broken down/stopped working or are you trying to get it to work in a way that it hasn't done previously, or adapt it's operation in some way)
Are you able to trace ALL of the wiring?
To be honest it'll be a pretty easy process to get the thing working exactly as you want it to and like most things in life it's easy when you understand what's going on and you get that lightbulb moment!
As you say the steps direction is affected by reversing the polarity to the motor, this will almost certainly be done by what's called 'double pole double throw or change-over contacts' at the RELAY so that's why the switches probably wont have a negative supply.
 
You must log in or register to reply here.

Users who viewed this discussion (Total:0)

Back
Top