Thread: Headlight upgrade for 90s 4wd

Originally Posted by svt40

Something often overlooked is voltage drop to the headlights - if youve got access to a multi meter see if you can measure the voltage across the bulb itself. Did a Narva training session about 25 years ago when i worked in auto electrical, and they said the difference between 13.8v (charging voltage) down to 12.5v reduced light output 30% - 40%. Putting thirstier bulbs in just made the voltage drop worse, and often they throw the light wrong as well with the filament in the wrong place. As someone else said above a couple of relays wired in can make a decent improvement just solving this issue with 80s/90s jap cars and their super thin wires.

That's why I suggested a relay system.
Power straight from that battery.
There is also another added bonus especially on a lot of models like most hiluxs. The switch on the headlight stalk on the steering wheel can't handle lots of voltage/amps. To much of an upgrade and they burn out. Using them to a switch a relay stops them burning out

Originally Posted by csmiffy

That's why I suggested a relay system.
Power straight from that battery.
There is also another added bonus especially on a lot of models like most hiluxs. The switch on the headlight stalk on the steering wheel can't handle lots of voltage/amps. To much of an upgrade and they burn out. Using them to a switch a relay stops them burning out

Most of the modern vehicles do actually run some form of relay for that reason - with the current model stuff the switches are computer devices not switches as we know them. They only send a signal to the damn computer modules that then tell everything what to do...

Relay would be easiest thing to try first. Pretty simple to wire up as well. Not on this vehicle but be careful if putting relays into computer controlled circuits as well make sure your Earth's are good as well