Headlight Relay(s)

[victor72]

Having acquired a pair of halogen headlights to replace the standard sealed beam units, I understand that the fitting of relays into the headlight circuit is recommended to both prevent my headlight switch cooking and to maximise current to feed the halogen bulbs.

 

Can anyone advise the type of relays I require and also provide a wiring diagram ?

 

Thanks.

[foster461]

Having acquired a pair of halogen headlights to replace the standard sealed beam units, I understand that the fitting of relays into the headlight circuit is recommended to both prevent my headlight switch cooking and to maximise current to feed the halogen bulbs.

 

Can anyone advise the type of relays I require and also provide a wiring diagram ?

 

Thanks.

 

Take a look at Dan Master's web site. He sells kits but also publishes circuit diagrams.

 

http://www.advanceautowire.com/

 

I highly recommend his book too.

 

Stan

Edited January 28, 2007 by foster461

[Guest ron]

Hi

I've had halogen headlights in an MGB for 12 years and the TR6 for 6 years, my opinion FWIW is you don't need a relay, they are perfectly adequate for normal night driving without one and I've never had any problems with either the wiring or the light switches. The loom in the B is original and in the 6 was renewed when I restored it. I think you are just adding something else that can go wrong.

Ron

[victor72]

Take a look at Dan Master's web site. He sells kits but also publishes circuit diagrams.

 

http://www.advanceautowire.com/

 

I highly recommend his book too.

 

Stan

 

 

Stan

 

Thanks for providing url ... this is an excellent site with diagrams for relay wiring.

[victor72]

Hi

I've had halogen headlights in an MGB for 12 years and the TR6 for 6 years, my opinion FWIW is you don't need a relay, they are perfectly adequate for normal night driving without one and I've never had any problems with either the wiring or the light switches. The loom in the B is original and in the 6 was renewed when I restored it. I think you are just adding something else that can go wrong.

Ron

 

Ron - I might go with this option on your recommendation ..... saves money and time I could spend elsewhere on the car.

[Richard Crawley]

Victor

I used to have a Lucas relay powered off the H/light circuit to feed 2 x Lucas square spots I had fitted for many years before the restoration; despite refurbishing them ‘as new’, I haven’t yet refitted them! I converted to Halogen headlights as part of the resto but these are not currently powered through a relay. I admit I don’t drive the car much at night but I checked the wiring & switch contacts frequently during the first few months the car was first put back on the road but did not detect any hint any of overheating so, like Ron, I haven’t found the need to fit a relay; just make sure all of the contacts/connectors are nice & bright (rub with wire wool) & give them a smear of Vaseline when you fit them.

 

Having said that, it’s quiet easy to piggy back another Lucas relay on the bracket next to fuse box so it doesn’t look out of place if you feel it’s worth doing.

[jean]

You might be surprised, but my TR6 was equipped with Halogen headlamps from new The car was assembled in Belgium in early 70 and it was a dealer option. They were made by Cibié, a rather sophisticated layout with two separate reflectors and two bulbs as combined bulbs did not exist yet at the time. The wiring loom was left as it was without any relay.

Edited January 30, 2007 by jean

[67_gt6]

Take a look at Dan Master's web site. He sells kits but also publishes circuit diagrams.

 

http://www.advanceautowire.com/

 

I highly recommend his book too.

 

Stan

 

Printable colour wiring diagrams! well worth checking out

[badshead]

Printable colour wiring diagrams! well worth checking out

 

Yep, great site but wiring diagams are US spec.

[victor72]

Victor

I used to have a Lucas relay powered off the H/light circuit to feed 2 x Lucas square spots I had fitted for many years before the restoration; despite refurbishing them ‘as new’, I haven’t yet refitted them! I converted to Halogen headlights as part of the resto but these are not currently powered through a relay. I admit I don’t drive the car much at night but I checked the wiring & switch contacts frequently during the first few months the car was first put back on the road but did not detect any hint any of overheating so, like Ron, I haven’t found the need to fit a relay; just make sure all of the contacts/connectors are nice & bright (rub with wire wool) & give them a smear of Vaseline when you fit them.

 

Having said that, it’s quiet easy to piggy back another Lucas relay on the bracket next to fuse box so it doesn’t look out of place if you feel it’s worth doing.

 

 

Richard

 

Many thanks. Headlights fitted and stainless screws used to secure, in lieu of originals. Headlights only work on main beam, with nearside brighter than offside. I'll set to work with wire wool, but have discovered a broken, stray earth wire near the horn wiring which may be the culprit. The horns will also be replaced and wiring cleaned and checked. V

[victor72]

You might be surprised, but my TR6 was equipped with Halogen headlamps from new The car was assembled in Belgium in early 70 and it was a dealer option. They were made by Cibié, a rather sophisticated layout with two separate reflectors and two bulbs as combined bulbs did not exist yet at the time. The wiring loom was left as it was without any relay.

 

 

Excellent - even more weight to the view that a relay may be omitted from the headlight circuit

[Vitesse Jason]

Excellent - even more weight to the view that a relay may be omitted from the headlight circuit

 

You only really need to add a relay if you are drawing more watts than standard. Just adding halogen bulbs of the same spec wattage as original won't do this. Adding say 100w mains will put a strain on old wiring and especuially old switches and so relays are essential. However, if you're only upping the mains and leaving the dips as standard then you only need relays on the main beam circuit - basically above standard watts means thicker supply wire and relays or risk a melt down and potential fire risk