people who have used/installed Mallory 685 ignition box...
03-23-2008, 08:47 PM
#1
people who have used/installed Mallory 685 ignition box... So I bought a Mallory 685 for my 1994 T/A with future nitrous install. Anyway I'm trying to hook it up just to get it in for now and make sure it works. I used the MSD harness to get it all done. I ran into a few problems during install though. Keep in mind I have a 1994 with a dual connector coil.
1) I talked to a guy that used the same harness and box in his 94 Z28 and he told me to only disconnect 1 of the connector's on the coil and plug it into the harness and then put the plug from the MSD harness back into the coil so that both connections on the coil were used. I did this and the car wouldn't fire. I then used the instructions that came with the box and put both stock plugs from the coil onto the harness and then the 1 plug from the harness onto the coil. It then started fine. I'm only worried about this because the guy with the Z28 said he only unplugged 1 of the stock plugs from the coil. What is the correct way?
2) Also there is a a long hot and ground that comes from the box, red and black wires of course. Once again the guy with the Z28 told me to obviously ground the black one and put the red to a switched 12 volt. But the instructions told me to put the red straight to the battery. What is the right way on that?
3) I have it in and it seems to work but the box makes a humming noise. Think this is due to the wiring being screwed up or due to the box being bad?
Like I said I think I have it in correctly since it starts up and everything and the box powers up but I just want to make sure.
1) I talked to a guy that used the same harness and box in his 94 Z28 and he told me to only disconnect 1 of the connector's on the coil and plug it into the harness and then put the plug from the MSD harness back into the coil so that both connections on the coil were used. I did this and the car wouldn't fire. I then used the instructions that came with the box and put both stock plugs from the coil onto the harness and then the 1 plug from the harness onto the coil. It then started fine. I'm only worried about this because the guy with the Z28 said he only unplugged 1 of the stock plugs from the coil. What is the correct way?
2) Also there is a a long hot and ground that comes from the box, red and black wires of course. Once again the guy with the Z28 told me to obviously ground the black one and put the red to a switched 12 volt. But the instructions told me to put the red straight to the battery. What is the right way on that?
3) I have it in and it seems to work but the box makes a humming noise. Think this is due to the wiring being screwed up or due to the box being bad?
Like I said I think I have it in correctly since it starts up and everything and the box powers up but I just want to make sure.
03-24-2008, 01:14 PM
#3
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I have a 95 Z28 with the box installed for my nitrous application.
1.) Unplug both connections and plug both connections into the MSD harness as you did. I think the other end of the MSD harness only has one of the plugs that goes onto the coil though.
2.) The long red wire needs to go directly to the battery for constant power and memory. The black is ground. The box uses the wiring from the coil for the switched 12v+.
3.) I am not sure about the humming. Once you have it hooked up right it may go away.
1.) Unplug both connections and plug both connections into the MSD harness as you did. I think the other end of the MSD harness only has one of the plugs that goes onto the coil though.
2.) The long red wire needs to go directly to the battery for constant power and memory. The black is ground. The box uses the wiring from the coil for the switched 12v+.
3.) I am not sure about the humming. Once you have it hooked up right it may go away.
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glad it runs. Not sure if mine hums or not.
03-24-2008, 04:07 PM
#9
Yea I figured he was wrong after i looked at the instructions. But I just wanted to make sure and ask here.
Think maybe it needs to be grounded better to stop the noise? I grounded it behind the kick panel on an existing ground that was already there. The ignition box is in my glove compartment so it is kinds noticeable when it is humming.
Think maybe it needs to be grounded better to stop the noise? I grounded it behind the kick panel on an existing ground that was already there. The ignition box is in my glove compartment so it is kinds noticeable when it is humming.
03-25-2008, 04:24 PM
#11
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Just teach it the words and it will stop humming. In all seriousness, what is the point of the box? Is the factory stuff that bad? Just trying to figure out my own build here.
Chris
Chris
03-25-2008, 04:55 PM
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03-26-2008, 11:25 AM
#15
Some people use the box for everything on their nitrous setup. The box can be used as a window switch, hotter spark, pull timing, and a 2 step. I'm just gonna use it to pull timing and a hotter spark since I bought Nitro Dave's dual channel window switch because it will allow me to lock out 1st.
