Spotlights - Doing it right

[Banshee]

So the Ring Spotlights that I got dirt cheap a while ago from Halfords have been mounted to the car but have never been wired up and with the bad weather coming and dark nights I'd like to be able to make use of them.

I wired my old ones up in the Maverick and the wiring job I did was terrible and I didn't use and Relays, I know nothing about Relays, but I've been told that I should be using them if I'm wiring them in right. Where can i buy these from and how do I wire them up? I have more questions but we'll go one at a time :thumb2

 

[jims-terrano]

Checkout the how to guide in the downloads section:thumbs

Basically take a feed from the high beam circuit to the relay, you'll also need an earth for the relay too. Then a live straight from the battery via a fuse to the relay and then last connection is from the relay to the lights.

You can find wiring kits on ebay dirt cheap with fuse holders relays and instructions. I've bought all the bits seperately from ebay too. Big thing is make sure you have a fuse as near to the battery as practical.

 

[Banshee]

Checkout the how to guide in the downloads section:thumbs

Basically take a feed from the high beam circuit to the relay, you'll also need an earth for the relay too. Then a live straight from the battery via a fuse to the relay and then last connection is from the relay to the lights.

You can find wiring kits on ebay dirt cheap with fuse holders relays and instructions. I've bought all the bits seperately from ebay too. Big thing is make sure you have a fuse as near to the battery as practical.

Thanks for the hasty response Jim :thumb2

I plan on having the 4 on the roof on one switch and the 2 on the bumper on another, so I'll need 2 relays. How are they rated?

 

[jims-terrano]

Im on my ipad at the moment so can't post any links but I'll take a look and show you what bits I have used in the past.

 

[The Patrolman]

Show me wot you got:naughty
And I'll bring some bits over on Friday and we can have a look at some point.
You might need them Saturday night if we do a night run.:nenau

 

[Banshee]

Thanks both :thumb2

Steve there's no way I'm doing it Friday :lol but bring some relays along etc to show me what the score is

 

[The Patrolman]

Thanks both :thumb2

Steve there's no way I'm doing it Friday :lol but bring some relays along etc to show me what the score is

I'll have a root whilst I'm in the garage tomorrow sorting the truck.

Hardly touched it since we were out last:thumb2

 

[Sweety]

Yes you will need 2 relays tbh 1 30a relay might cope if you stick to 55w bulbs but it'll be running just off max current:augie On my old T2 the front spots on the bumper came on with main beam via a relay the 4 on the roof again came on with main beam but I fitted a switch on the dash so they could be turned off for MOT time etc. You'll want 20 amp min cable to wire up the roof lights:thumbs I took the relay switch on feed from the main beam wire at the back of the O/S headlight but when I get around to doing this truck i'm thinking of tapping into the main beam feed wire somewhere inside the cab just not sure where at the min

 

[glanrichbex]

Relays are old hat mechanical devices - much easier to use FETS, they don't wear out, you don't get back emf issues, their switching resistance is far lower so virtually no loses, I wouldn't use relays ever again for this sort of work.

One wire from the battery to the source, another wire from the drain to the lamp, from the other side of the lamp to chassis.

The gate connected via a 1K resistor to the live feed of what ever you want your new lamp to follow.

Just bolt your FET to a heatsink and bobs your uncle.:thumbs

 

[Banshee]

Yes you will need 2 relays tbh 1 30a relay might cope if you stick to 55w bulbs but it'll be running just off max current:augie On my old T2 the front spots on the bumper came on with main beam via a relay the 4 on the roof again came on with main beam but I fitted a switch on the dash so they could be turned off for MOT time etc. You'll want 20 amp min cable to wire up the roof lights:thumbs I took the relay switch on feed from the main beam wire at the back of the O/S headlight but when I get around to doing this truck i'm thinking of tapping into the main beam feed wire somewhere inside the cab just not sure where at the min

Thanks for the advice Sweety, I may be back in touch soon :thumb2

Relays are old hat mechanical devices - much easier to use FETS, they don't wear out, you don't get back emf issues, their switching resistance is far lower so virtually no loses, I wouldn't use relays ever again for this sort of work.

One wire from the battery to the source, another wire from the drain to the lamp, from the other side of the lamp to chassis.

The gate connected via a 1K resistor to the live feed of what ever you want your new lamp to follow.

Just bolt your FET to a heatsink and bobs your uncle.:thumbs

I think I'm going to go Relays I can't find anything on FETS on web :nenau

 

[harlowmaverick]

Any pictures of mounted lights and what are fets?

 

[jims-terrano]

Fets are electronic replacements for relays. Instead of being a mechanical switch operated by an electro magnet it is a electronic switch. Not seen them available on the motor spares market yet. Thye have their advantages as posted about earlier. Only ever had one relay go faulty and have to say it was my own fault really. I think for the small current draw of a relay in this application relays are the way to go.

As I said earlier make sure you have fuses in the circuits.

 

[Sweety]

Any pictures of mounted lights and what are fets?

My old T2 god I miss this truck:doh Jim you were out with us in the Dales when this pic was taken:thumbs

 

[Lazy-Ferret]

One problem with FETs is when they fail, there is no isolation between the control circuit and the heavy current device, which can cause catastrophic problems, especially on cars with modern electronic controls.

Fusing becomes extra important, with critical importance on making sure you get exactly the right values in the feed to the contrpl side of the FET. Also FETs have a small volt drop, which relays do not tend to have, which can become quite noticable when used on high current devices that want every ounce of what is available.

FETs are fine if you know what you are doing, but for most people, Relays are the safest and easiest option.

Sent from my SM-T705 using Tapatalk

 

[jims-terrano]

Yeah I remember it well neil, fantastic day out was that and a grand little swb neil. Why on earth did you part with it

 

[Sweety]

Yeah I remember it well neil, fantastic day out was that and a grand little swb neil. Why on earth did you part with it

Almost parked it on it's side that day as just before that ford the rocks washed out under me I sold it to buy the V8 & still regret it:doh:doh:doh it's still on the road tho so if I ever see it up for sale & it's in not to bad a shape i'll be having it as a toy

 

[glanrichbex]

One problem with FETs is when they fail, there is no isolation between the control circuit and the heavy current device, which can cause catastrophic problems, especially on cars with modern electronic controls.

Fusing becomes extra important, with critical importance on making sure you get exactly the right values in the feed to the contrpl side of the FET. Also FETs have a small volt drop, which relays do not tend to have, which can become quite noticable when used on high current devices that want every ounce of what is available.

FETs are fine if you know what you are doing, but for most people, Relays are the safest and easiest option.

Sent from my SM-T705 using Tapatalk

Fets have virtually no voltage drop at all, they go down to 0.007ohm which is far better than a set of resistive mechanical contacts . No arcing, no back EMF, 100microamps to bias it instead of 0,5amp holding current using a coil. The gate feed resistor is not critical as its voltage control not current unlike a Bipolar transistor. When Fets fail they go short circuit, this is very rare but you should fuse any additional modification regardless if its relay or FET.

Relays are fast becoming a thing of the past, FETs have been around for 30years, in the last 15years the technology has just escalated beyond any expectations we had in the 80s. The smallest T023 packages are capable of 50amps or more. They really are amazing devices used everywhere.
You only need 1 FET ( say IRF540 ) and a 1K resistor - don't be scared of them, they really are much simpler than relays and far more reliable. :thumbs

 

[glanrichbex]

Any pictures of mounted lights and what are fets?

FETS are Field Effect Transistors.

They behave very similar to a transistor where a small voltage at the gate terminal will allow a large current to flow between the source and drain terminals. The advantage of using FETS is that when they conduct, they have incredibly low resistance so you get maximum power transfer unlike a set of relay contacts where you can loose up to 5% in contact resistance.

FETS have a built in safety characteristic where they don't suffer thermal runaway unlike a conventional bipolar transistor, as they get too hot they conduct less so don't blow them selves up.