Mustang Owners Club Australia Forum

Technical & General Discussion Area => Tech Torque 1974 to 1978 => Topic started by: fatso1 on November 11, 2020, 06:02:43 pm

Title: 67 headlights flickering
Post by: fatso1 on November 11, 2020, 06:02:43 pm
Hey Gang haven’t posted in a while but I want to start using my 67 stang again.
I got it direct from USA 15 years ago I have never been able to drive at night because after 5 -10 mins the headlights start flickering on and off does anyone know what the cause of this is? When vehicle came from USA we changed headlights to be compliant in Australia
Title: Re: 67 headlights flickering
Post by: GLENN 70 on November 11, 2020, 06:13:10 pm
Fit a new headlight switch . If you up graded the lights from the old sealed beam ones you should have a relay fitted .
Title: Re: 67 headlights flickering
Post by: pgold on November 11, 2020, 11:11:28 pm
search e-bay - headlight relay loom kit. you connect loom to battery, connect one of existing headlight sockets to loom plug ( to control new relays ) and connect up headlights. If your new right hand drive headlights are higher wattage then the originals then you may be overloading the thermal circuit breaker in light switch. A new switch may or may not fix problem.
Title: Re: 67 headlights flickering
Post by: SMH00N on November 12, 2020, 09:35:27 am
The reason is the extra load in the new lights overloads the headlight switch.
Put in a relay for both low and high beam circuits (2 relays) with new wiring from relay to headlights.
No need for a new switch, the load comes off the switch when you use a relay as it only triggers the relay and carries low load.

If you are not up to wiring a decent sparky can do it. If you want to keep it original, the wiring doesn't need to be replaced but if you do it's not going to give you any hassle.
Title: Re: 67 headlights flickering
Post by: Dwayne on November 12, 2020, 09:54:55 am
Fitting the headlight relays is really easy.

I had no wiring experience and easily fitted the relay in about 30mins.
Title: Re: 67 headlights flickering
Post by: GEOFF289 on November 12, 2020, 12:28:12 pm
Fitting the headlight relays is really easy.

I had no wiring experience and easily fitted the relay in about 30mins.

Ditto, one of many things on the "if I can do it, anyone can" list.
Title: Re: 67 headlights flickering
Post by: fatso1 on November 12, 2020, 10:24:05 pm
Will the attached loom work?
Title: Re: 67 headlights flickering
Post by: SMH00N on November 13, 2020, 09:03:52 am
You need to know what watts the headlights are, to make sure the cable can take the load. This is critical for the power cable as it supplies all the power needed.
55 w low beams will pull 9 amps, 60w high beams a tad more (divide watts by volts; 55/12= 4.5 (or actually 110/12 = 9.16))
So on high beam you are going to need a cable to can cope with 20 amps (working on all 4 lights being on).

That harness looks at a glance to be 3mm wire which tops out at 20amps - in a quality cable. "Yes" it will work but with barely enough redundancy to cover you driving down a dark country road at night.
I went 5mm power wire for my setup and 3mm wire for the light harness. Overbuilt it, won't worry about it again.

If you want to buy something, look at these guys: https://bluewireautomotive.com/products/headlight-relay-booster-power-wiring-harness-kit-40amp-h4





Title: Re: 67 headlights flickering
Post by: pgold on November 13, 2020, 06:50:23 pm
What wattage are your headlights? Are they sealed beam or halogen? If you have good lights will you do much night driving?
Title: Re: 67 headlights flickering
Post by: fatso1 on November 13, 2020, 07:37:55 pm
Sealed beam I have just ordered that look from blue wire I won’t do much night driving but it’s a pain in the arse not too or to have to make sure I’m home before dark for $70 for the relay kit should be well worth it
Title: Re: 67 headlights flickering
Post by: pgold on November 13, 2020, 08:13:27 pm
The cheapest units are probably cutting corners some ware ie: cable gage or relay quality. The unit you chose should allow you to upgrade to H4 halogen with higher wattage or LEDS - which I now little about and not shore they will fit in our headlight buckets???
Title: Re: 67 headlights flickering
Post by: AussiePhil on November 14, 2020, 06:17:09 pm
Hey all.
I bought the $16.99 version and was astounded by it's great quality!
Cheers Phil.