System Wiring ??

EDIS and Megajolt installation related topics. Be sure to review the <a href="http://www.autosportlabs.net/MJLJ_V4_vehicle_installation_guide">Vehicle installation guide</a>

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tH3 t0yM4k3r
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Joined: Wed Nov 10, 2004 2:52 pm

System Wiring ??

Post by tH3 t0yM4k3r »

I’m planning to install EDIS-8 and the MJLJ unit on my ‘68 Cougar, but I had a few wiring questions before I started.

I have seen several contradictory wiring diagrams as far as how to deal with the shielding on the wires coming from the VR sensor and the wires connecting the EDIS module to the MJLJ unit. Do they need to be grounded to pin #7 on the EDIS module, or not at all, or grounded somewhere else?

Also, where am I supposed to get my power for the EDIS module and MJLJ unit? I know the EDIS module is supposed to be connected to a switched 12 volt source, but can I run it off the solenoid or do I need to go straight to the battery. As far as the MJLJ unit, there are 2 12 volt sources. I’m assuming that one is supposed to be a permanent 12 volt to maintain memory and the other is supposed to be a switched source. Am I correct? And if so, which one is which?

Sorry for all of the questions.

dermot
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Joined: Wed Sep 22, 2004 11:28 am

shield

Post by dermot »

Hi,

The VR should use a screened cable, and that screen should be connected at the EDIS end only. This is how Ford did it also.

The EDIS and MJL can both be connected to, for example the normal switched ignition supply. The MJL and EDIS do not themselves really take much current at all, it is the coils, which should get their supply another way, which use power/energy. The 2 12v's on the MLJ are commoned anyway.

My own view is that the common point for grounds and 12v is the EDIS unit, i.e. the MLJ gets it's 12v and it's ground from the EDIS ground and +12 points.

In <theory> you should not probably need to screen the signal lines between EDIS and MJL, however I will on my install - I'll just use a screened multicore to take the ground across as the screen for all the EDIS<>MJL cables.

br

Dermot.

tH3 t0yM4k3r
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Joined: Wed Nov 10, 2004 2:52 pm

Thanks for the information.

Post by tH3 t0yM4k3r »

Thanks for the information.

I just had one more question. I've never delt with screened cable before, so how do I connect the screening at the EDIS end?

brentp
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Fyi, The shielded part of

Post by brentp »

Fyi,

The shielded part of the cable is designed to be grounded.
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msinisal
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Joined: Tue Nov 23, 2004 10:57 am

Polarity of VR sensor

Post by msinisal »

Which one of the two VR sensor wires is plus, and which one is minus? Does the polarity even matter?

tH3 t0yM4k3r
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Joined: Wed Nov 10, 2004 2:52 pm

If you’re using a Ford VR s

Post by tH3 t0yM4k3r »

If you’re using a Ford VR sensor, then the blue wire is negative (-) and the grey is positive (+)-at least as far as I know-.

If you reverse them, then your signal will be inverted and things won’t work properly.

tH3 t0yM4k3r
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Joined: Wed Nov 10, 2004 2:52 pm

Got another question. I’m

Post by tH3 t0yM4k3r »

Got another question. I’m probably going to use the single wire that feeds my current single coil to feed the two EDIS coil packs. Will I need to install a relay before I split off to the coil packs?

ckenyon
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Joined: Tue Jan 31, 2006 12:35 am

shielding and ground

Post by ckenyon »

The oem installation has the shields for both the pip/saw and VR connected together then connected to the edis. Don't connect the shields to ground. I had rpm and advance problems that way.

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