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Old 12-23-2009, 09:14 PM   #1
Super73
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Join Date: Nov 2007
Location: Bay Area, Ca
Posts: 2,841
OK.. I need some N20 help.. It's a weird one..

Attached you will find a wiring diagram that I created for my set up. A few things about it.

2 stage NX kit.
2 arming switches, one for each stage.
Throttle switch
Fuel pressure safety switch
Single Window switch: Can not take a large ground (like noids) so I am using it to ground the coil of the relays.

I was testing it last night in the shop with it wired as shown minus the window switch. I didn't want to be reving the motor while my buddy tried listening to noids ect to see if things were working. The wire going from the Fuel Pressure Safety was left loose so I could simply ground it to the chassis as if it were through the window. Things weren't working right.

We found that some how there was a grounding issue and when arming the system (with the WS wire grounded) it was firing the noids with out the throttle switch being depressed. Double checked the throttle switch with a meter to make sure it was normally open and working right. All is fine with it. So we decided to disconnect the input of the throttle switch (ground from the relay coil 86). Flip the switches, still firing the noids.

We disconnected the 86 wire from relay and tested our circuit for a short to ground, IE through the throttle switch and through the fuel pressure safety switch. No short or ground.

The next thing we check were the arming switches since they go to ground for the LED or light in them. +12 in and Acc both are free of ground when off but both go to ground when on.

We disconnected the ground for the arming switches, and what do you know. Works perfect. Each stage will engage and release with the throttle switch, and both will as well if they are both armed.. They both work right with the window switch wire being manually grounded and ungrounded as if I was the switch..

I swapped (85) and (86) for the fun of it to see if any difference. No I didn't notice if it was doing this or not with them wired as the diagram but:

If the ground is hooked up to the arming switches, if 1 stage is armed alone with the WS wire grounded, the noids will not fire till WOT, but, they will not release if I lift or unground the WS. I have to turn the switch off. But if both stages are armed, they both will come on and off with the throttle assuming the WS wire is grounded.

Again, disconnecting the ground on the switches, works perfect.

So I'm hoping someone can tell me what would be causing this. I'm thinking I might just buy a couple nonlighted switches since I know it works right that way..

Would putting a diode on both (86)'s possibly fix the issue?
Attached Images
 
__________________
------Motor---------------Bottle
60'---1.53---------------1.41
1/8---6.58 @ 105.92----5.87 @ 118.41
1/4---10.38 @ 126.97----9.24 @ 142.49
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