nitrous switch questions - Honda Prelude Forum

alphajesse · 03-18-2003, 04:57 PM

Ok, I just got my USDM foglight switch from Mark (wreckdriver)
I'm gonna be using this as my n2o switch and had some questions. Do you think the switch can handle the 12v, or should i use the harnesses' relay?
Also, do you think I might be able to take advantage of the factory wiring which prevents foglights from being on with the parking lights or highbeams to trigger the purge (flash the beams to purge would be badass!) or should i forget that idea?

alphajesse · 03-18-2003, 05:45 PM

Ok. I'm gonna use the harness relay to activate the system.
I figure using the system as-is will allow me to just hook the line comeing from the engine bay's relay to the orange one from my harness will work. N2O will work with headlights on, but not parking lights or highbeams.
How can I modify my setup to allow the nitrous to turn on at any time, firstly?
this thread right here shows me how to do that.
Updated: USDM Foglight harness mod
any ideas on how i can get the 2nd relay to trip and activate my purge by either turning on or flashing my highbeams?

alphajesse · 03-18-2003, 09:05 PM

i got the system wired through the foglight switch. for now, only when the headlights are on does it work. good stuff. i've ordered the foglight switch panel, and it should look ultra clean.

Padge · 03-18-2003, 09:53 PM

how many amps can the switch handle?

Ive melted a switch before... but that was for the heater

CTPRELUDE · 03-19-2003, 12:03 AM

I like your idea, but only juice while the headlights are on? I would rather just use the switch without any lights. Just my opinion.

alphajesse · 03-19-2003, 01:01 AM

well, I'm using the USDM interior fog harness, and the USDM switch. I didn't feel like rewiring the relays on it until i knew it worked. I might rewire it later, but I ususally race at night, so headlights on is no biggie.
I just want to figure out if I can rig the highbeam flasher to trip my purge.

Padge, the harness has a 15amp fuse built into it. The switch itself probably sees much less than that.

ZMonkey11 · 03-19-2003, 11:19 AM

hahahaha...if i ever see a prelude coming up next to me that has his headlights on during the day and is flashing his highs, i will defnitely avoid racing it. LOL

alphajesse · 03-19-2003, 11:23 AM

I'm gonna get around to making the nitrous work whenever I want, but I'm still gonna try to figure out how to purge with the highbeams.

axion68 · 03-19-2003, 11:42 AM

as long as you aren't powering any solenoids with the fog switch you are fine. you really only want to have the switch powering a relay. If you need any help on mapping the relay (the black one) I can see if I still have any notes on it. I'm not sure on the high beam purge, but check the garage door opener thread and see if they have any info on the high beam. Are you just trying to have a stealth install?

alphajesse · 03-19-2003, 02:58 PM

stealth install is the name of the game, jake. i was waiting for you to get into this thread. i didn't think about the garage door opener thread, but now that i think about it, i remeber someone asking about that possibility. thanks for the lead!
yeah, this just turns on the relay in my engine bay.

axion68 · 03-19-2003, 06:14 PM

ok, I don't have all of my papers on the relay, but I found one. grab a test light or something just to make sure, but this is how I have the relay mapped on paper

Code:

[1][2]
       ]
[3][4]

1- headlight ground
2- fog switch
3- foglight
4- ac+12
the lonely ] is the notch on the brown connector.

you will want to use the number 3 wire (should be 2 orange wires if I remember correctly). You are going to need your headlights on for the switch to work (I assume it will be the arming switch). you can do this mod. The orange wire goes through the relay, and enough amperage can pass through it for the fogs so it should be plenty.

Padge · 03-19-2003, 06:55 PM

remember, you dont want someone who is unfamiliar with your car accidentily hitting your arm switch unknowingly.

IE when you put your car in the shop.

axion68 · 03-19-2003, 07:45 PM

he could always put a small toggle switch in like the engine bay or something, or even put disconnects inline of the signal wire to the relay.

alphajesse · 03-20-2003, 12:48 AM

Quote:

Originally posted by Padge
remember, you dont want someone who is unfamiliar with your car accidentily hitting your arm switch unknowingly.

IE when you put your car in the shop.

thanks for the warning, but the bottle is not in the car when i am not. so if they trip my 'noids, no biggie. that or i can just disconnect the main power for it.

jake, i've already got the orange wire that normally goes to the fogs activiating my 'noid relay. (i have no foglights, and never will) so my arming switch is settled with that (it works well, btw)
unless that is how you propose i do my purge? But that line doesn't have continuity unless the headlights are on? i'm not quite following you-
my plan is, nitrous on with the button, no matter what the headlights are doing, but purge 'noid tripped by the highbeams. i don't mind hacking into the usdm harness, but i'm not seeing how what you just posted will work. what does the other relay control in this mess? is that the one that sends the power out of the harness to the lights? or is that the one that deals with the highbeam grounds?
i'm thinking i can do the 'always on' mod and use the other relay (which i assume has the parking light ground and highbeam ground) remove the parking light ground(i don't care what those are doing), and send the output of that mess to another lead that will control the purge's relay. i might have to use the helms wiring diagram for this! arrgh!

alphajesse · 03-21-2003, 05:30 PM

ok. i'm just going to use a regular momentary switch for my purge. does the usdm harness mod make the foglights work with the highbeams on, or does that only make it work with lowbeams, parking lights and no headlights?

axion68 · 03-21-2003, 07:57 PM

the gold relay cuts the power to the fogs when the high beams are on, I never mapped that relay out. it would only take a few minutes with a test light though, but I'm pretty sure there would be a way to wire the high beams to purge. Just remember that if you set it up this way your purge will go off whenever you flash your high beams (I'm sure you already thought of this). You could setup another relay, but I think that would start to complicate such a simple thing.

alphajesse · 03-22-2003, 01:54 AM

yeah, I'm gonna go away from that highbeam flashing thing. i realized that the harness probably does not differentiate from flashing (the momentary switch) or keeping them on. most night races i do have the highs on for greater visibility.
quick question-- does that usdm harness mod in GD keep the fogs on with the highbeams? it's not too clear in the thread, and I haven't got an answer over there by asking. if they still turn off with the highs, i guess i'll start mapping that relay.

axion68 · 03-22-2003, 10:27 AM

no, the high beams will turn off the fogs. the stock harness will only allow the fogs to have power when the headlights are on, and with the mod you are able to turn the fogs on with your parking lights as well as the headlights. I didn't mess with the high beam relay, however I bet it is quite simple.

axion68 · 03-22-2003, 10:30 AM

since you are only powering a relay, you could remove the black relay and short the 2 and 3 wires (I believe). this does route all the power going through the orange wire through the fog switch, but since you are only powering a relay the switch should be beefy enough for that.

alphajesse · 03-24-2003, 02:51 PM

ok i got it figured out now. this is how to do it. USDM foglight harness mod, part II
plus i still have the relay ready to use to make the highbeams turn something off!
maybe i can purge when i turn on the system with the switch and headlights on, then stop purging when i turn on the highbeams!