A brief explanation of what a relay is, and how it works

[@jamieaustin6403]

Well explained. As a sparky myself you made it nice and easy for people to understand.

[@BritannicaRestorations]

great stuff!

[@yenoh243]

Thanks for “Relaying “ that information for those that don’t know. 😊

[@BritannicaRestorations]

You bet!

[@gshort4707]

Hi Mike, I know you said it doesn't matter which way round you connect 85/86 and that can be true. However, the relay you show at 9:15 has a "flyback" diode (also known as "freewheel") which are also fairly common. For those relays you should connect negative to 85 & positive to 86. It is still true that 30/87 can be whichever way round you want.

[@jamesanderson84]

Very helpful Mike. Always knew I needed them but never quite knew what they did and how they worked.

[@BritannicaRestorations]

Glad to help

[@MrRobmellor]

Once again, a really helpful video made for the person that hasn't got a clue until they watch your video. I cant wait until you do a more in-depth video on this subject. Do you remember the Volvo dipping relays, they had a ratchet in them that turned a cog that switched the power from main to dipped beam, they could be a right bugger. By the time someone has watched all your video's, it will be as if they had done an apprenticeship and were time served. Hats off to you Mike. Best wishes from Yorkshire Rob.

[@BritannicaRestorations]

I may do some wiring videos over winter

[@harveysmith100]

Mike, I fully understand how relays work, I can even explain to others but I thought I would watch anyway. Still bloody learned things!! Thanks for the effort in making this. You'll have to clean your bench as well now!

[@BritannicaRestorations]

Right on!

[@selligsgarage3262]

I have been an automotive electrician for a very long time, ( and LR anthousiast too) and I must say: Excellent explanation. By the way, the normal consumption of the control circuit of a relay is about 100mA (0.1A). Thanks Mike !

[@BritannicaRestorations]

Great to hear!

[@andrewevans7184]

Brilliant! I had a basic understanding of how they worked but knowing about the Numbers on each of the pins it's really helpful. Thanks Mike

[@BritannicaRestorations]

Glad it was helpful!

[@tanchunghong1700]

Really helpful video! Please do the headlamps circuitry video as I’m having problems with my main beam going off unless I “kick in” the high beam for a few seconds…

[@j3652]

"There's one I broke earlier" should be added to the unofficial Land Rover mottos! Cheers Mike, another informative video

[@BritannicaRestorations]

Lol!

[@greebo7857]

Fitting a relay to Defender headlights not only makes them brighter, it also protects the hi/lo stalk from burning out...

[@BritannicaRestorations]

Correct!

[@pabloberridi]

Thanks Mike for your time on this topic 👍

[@BritannicaRestorations]

Any time!

[@johnchetwynd3618]

Hence the dim as a Toc H lamp syndrome with Defender headlights. Not fed through a relay and with the length of the wiring a reduced voltage reaching the headlamps. It also is the reason why the switches burn out. Fit something like the Boomslang loom and see the difference 😊

[@harveysmith100]

Very good point.

[@malcolmyoung7866]

Clear as mud, Mike.. electricktrickery is my nemesis… ever since I stuck my fingers between two extension plugs… luckily I was sat on my potty at the time…

[@zebratruck]

Good video Mike. My ‘86 LR 90 has no low beams. New switches too. I’m probably going to install relays on hi and low beams and hopefully this will fix things. Excellent videos all around bud, especially the older ones on the 2.5 NA diesel. That’s what’s in my exRAF 90 and I used your video to get my fuel system primed after running out of fuel.

[@BritannicaRestorations]

Go for it!

[@D3fender110]

Thank you! Best explanation I’ve heard.

[@BritannicaRestorations]

Thanks!

[@olewurtz7625]

Well explained.

[@gazzafloss]

Hey Mike that was a good lesson on relays or as they call them in China, "Leelays", what they are and what they do, extremely useful devices. A suitably fused main power supply right at the source is always advisable.

[@BritannicaRestorations]

Indeed, fuse requirements would be like walking in treacle as there are so many permutations!

[@anthonysookwah9083]

This is a great video

[@abstractgroove160]

This was a fascinating and very clear explanation, but I've still absolutely no idea what's going on 😂

[@BritannicaRestorations]

Me neither

[@peterjohnson2245]

85 and 86 'the coil' there is a 'correct way' to connect them but in most cases as you say it doesn't matter. It is imperative you get the ones fitted with diodes in the correct way round (this is to stop the back EMF of the coil). Mike and others I am sure you know what I am talking about. Diode relays are not that common but are used where the EMF of a coil could impact the control circuit. For those interested... When you disconnect a coil of wire from its power source there is what is called an back electromotive force generated (back EMF, In the movies they use an EMP, P=pulse to wipe out electronics) back EMF can be thousands of volts but at very low current. It is actually how the coil on a petrol engine develops the HT (high tension or high voltage) for a spark! (learnt the hard way on that one pulling a plug lead off with the engine running!) I can't remember which way ATM but most people don't need to worry about it.

[@BritannicaRestorations]

Correct, but in general use for lights it is not so important - I should have mentioned it, but the one I used close up, was a relay I pulled from the collection I have to show different styles

[@vincentpoole7588]

Mike. A very good explanation mista ! How does a relay work on later style 'multiplex' electrical systems sir ? V.

[@graham-martin5847]

i love relays ive made a full harness for my landy for all the led lights on my roof rack as they suck a lot of juice my 4 led front roof spotlights have to have a 30 am fuse due to current draw this is were the relays come in

[@secpac58chichi]

if you have a discovery nas 1 you need to replace your VSS and CPS relays

[@quintincairncross1088]

Fascinating as always. Would an '03 TD5 have a relay in the headlight circuit?

[@BritannicaRestorations]

Not sure

[@jameskerr5756]

Was messing about with wiring and relays on my 1988 Defender last week as my headlights were permanently on regardless of whether the ignition key was in/on and the position of the light switch. Turned out to be the Dim-dip transformer gone breasts up. Think it was due to me changing the sealed beam units for ones with bulbs which were differently rated. Good old Lucas electrics eh!

[@simonroberts9759]

Hi Mike. Nice haircut by the way - early Birthday present?? For those of us who are not skilled with relays, please could you explain what the numbers mean? Thanks Simon

[@nickosborne1982]

Could you give me an example of a 5 pin relay please.What/where would it be used in a defender

[@BritannicaRestorations]

Security systems spring to mind where a state has to be changed - hard to say on Defenders as they fitted the metal 5 pin as standard even though there were only 4 feed wires!

[@craigallen5469]

I was told my 1993 defender tdi 200 doesn’t have a starter relay, but that can’t be correct can it?

[@BritannicaRestorations]

Could be - there were so many variants of harness

[@Defender110SLO]

If the fuse blows, you just insert a powerful one. 🤣 Cheers King Mike 🥃

[@tonypacke6954]

I think when Ford had their turn in owning JLR they went over all the electrics on the Puma and the Jaguar cars. Reliability improved almost overnight, especially with the Jag products. That's what happens when you chuck a load of money at a problem.

[@ScorpioxA1]

Anyway to fix a defender brown amr1088 relay that controles the alarm siren/hooter.Cant find one here for my defender.Thank you.

[@BritannicaRestorations]

rimmerbros.com/Item--i-AMR1088

[@ScorpioxA1]

@@BritannicaRestorations thank you money is a bit scares now i short a facsia for my td5 also and that is exspensive people are stripping for spares butt they dont want to sell stuff separate even that lightbulb holders of the temp gauge rev meter and fuel gauge the dontcwant to sell that on its own.🤷

[@doorstepheights]

Christ.....ya don't half get some crap in them finger nails!! (Every days a School day). 👍🏴󠁧󠁢󠁳󠁣󠁴󠁿

[@trevorfoster915]

Mike, you're so annoying. I'm having a competition with Charlie to see who can watch your videos first. So I'm on here constantly looking for the new one to come up. He's managed to get in at 30 views my best is 39. Today I went on every 10 minutes since half eight and then got embroiled in your drop arm video for fitting new ball joint . And what did you do?Put the new one on while I was watching it. I'll try again tomorrow . And wont get distracted this time. Try not to make them so good.