dimmer on 65w halogen?

hey guys, i have a lil project i've started on my '04 altima, which is trying to dim my hi-beams. i'm trying to achieve a day running light, without a day running light module/relay. i would love to connect a 12v dimmer if possible, whether i have to add relays, diodes, hell transistors. whatever i need to make a dimmer work on a pair of halogen bulbs, that'd be fantastic. i've done my searching on here, and here's what i've come across: https://www.the12volt.com/installbay/forum_posts.asp?tid=63127&tpn=1&PN=1 https://www.the12volt.com/installbay/forum_posts.asp?tid=66594 https://www.the12volt.com/installbay/forum_posts.asp?tid=96005&tpn=1&PN=1 http://alavigne.net/Motorsports/FeatureReports/S2000/DRL/index.jsp i've gathered all the info my brain can understand from these 4 links, though of course i have some questions of my own. i just know my basics of electricity. but when it comes to things other than wires, that's where i'm stumped. my dimmer that i would like to use is another nissan dimmer, since i can install it right next to the stock dimmer and would look oem. since this is a gauge/dash dimmer, it has 3 wires. are these 3 wires, 2 grounds and 1 power or vice versa?? after knowing the combination, how should it be wired? last resort: i would toss the dimmer idea, and just try to decrease the voltage?/current? to the bulbs with some kind of resistor or diode, etc. thanks in advance!

can anyone help?

They should be treated like LEDs - a chopped constant voltage aka PWM. 

Buy commercial {like the Hamsar 45060) ...

or build one (555 PWM to 80A MOSFET)......

. 

For fixed duty-cycle, can just use 2 resitors instead of adding the pot for adjustability - maybe use a trimpot for some adjustability.     

It can be in parallel with a relay (manual or timed as per that Hamsar link) depending on switching arrangment - eg, ground switching if powered from different voltage sources). 

Not series - half voltage is way under half brightness, and too cold therefore shortening bulb life. 

Same with other dimmers - resistive or analog - no good.   

thanks for your reply olspark. though i'm having a hard time reading this diagram you've posted, i will take the time to learn how to read it. so you're saying the dimmer is not a good idea for the sake of the bulb's life span, correct?

A resistive or analog dimmer not good for halogens and doesn't work for LEDs or fluor's etc. PWM techniques are ok - devices like the Hamsar are.

May I piggyback on this discussion? I also want to add Daytime Running Lights to some older Audi's and VW's by changing or adding running/fog lights that are wired directly to a keyed circuit so that the lights would be on when the key is on. Problem: 1.It would be perfect if I could find a voltage sensitive switch to disconnect the circuit when the voltage drops below 13V, i.e. engine not running. Any ideas? 2. The bulbs that I have in the Fog Lights are H3 (halogen?) that I wanted to wire in series so as to run a reduced wattage. I take it from your reply in this post that this will not work. Its hard to find ordinary incandescent bulbs these days. Any ideas?Ken

1. Charge light to sense if engine not running - see UIBI (Ultimate Intelligence Battery Isolator). Else voltage sensors (see stupid if you have a charge lamp "Smart Battery Isolators" or other low voltage cut-outs and battery protectors), but be aware of voltages dips, battery surface charge etc - ie, the UIBI is the simplest. For voltage sensing - maybe a MW-728 with diodes and a relay to increase its 11.2V cut-out voltage; driving a relay for the lamps (unless powering the PWM).    A 555 can also be used as a voltages sensor, but since 555s typically consume 10mA (even in standby mode) it is not a common or clever application for them. 2. Two halogens in series will be much dimmer than half the normal halogen (halogen output drops much faster than voltage).    Also under-voltage halogens fail quicker because of <whatever> buildups - they need full voltage (or heat?) to prevent this. Although I'm not sure on the technicalities of build-up, if it's a voltage issue, then PWM should overcome it - eg, see mp3car's Auto brightness with PIC (PWM) and ... (written by a rambler with a grudge!). If it's a heat thing, then PWM is no different to analog. Maybe one day I'll find out, but IMO it's over 20 years too late (and I just fitted a thermo-switch for my radiator's 12V cooling fan this year - I've been using the fan for over 30 years!) and since PWM would be used for these high power applications anyhow... (IE - aside from heat problems, the cost of high power resistors is much higher than the 555 & MOSFET circuit.)