View Full Version : Modifications Ceramic resistor
08-02-2011, 02:23 PM
So I'm in the final stages of cleaning up/rewiring my engine bay wiring after a fusible link meltdown and I've come across something questioning. When I rebuilt the car, I put the ceramic resistor back in that's in the ignition circuit. According to my wiring diagram, it's powered off the ignition switch and is in-line to the ignition coil and alternator regulator.
I've got an MSD 6AL on the car, so my question is, do I still need that resistor. The coil has been upgraded to a 40,000 volt coil and the regulator was replaced with an OEM style... I don't honestly see the need for it, but I don't want to pull it and cut some wires out if it's going to hurt something.
08-02-2011, 02:39 PM
I'd suggest call MSD and see what they say. I'm sure you're not the first to use their system in an old Mope.
08-02-2011, 04:00 PM
Thanks Dave! Maybe I'll try to give them a call tomorrow...
08-02-2011, 06:18 PM
Mike, not that I know for sure.. but I ran the MSD 6a on the superbird... and it still had the resistor.. put on 15 to 20,000 miles. I originally put on the MSD to clean up emmisions at idle, but it made that 440 a super starting motor, if it would turn... it would start.
08-03-2011, 07:00 AM
Did a little testing last night and that resister is a MUST. Car fired up with it, shut it down and pulled it out. Car would fire for a revolution then die. No matter how many times I tried, it wouldn't run without it in. Good to know as a little added security at cruise nights. :) Not to mention the ignition cutoff switch I have. Slowly getting back into the swing of the car world down here... and I thought it would get hot at shows up there. Whew!
08-03-2011, 12:21 PM
As the OEM wiring is done you need it to complete the circuit but a 'race' (not OEM direct replacement) coil and MSD6A do not want it in the system. They will run on the 9v, but they would rather have the 12v. I eliminated the ballast resistor in the Fury when I went to EFI and my super coil and MSD6a loved it. If you read the 6a manual you'll see the same thing.
08-05-2011, 10:09 PM
So what'd you end up doing with the 2 connections for the resistor? Can I just hack the connections off and splice them together?
08-07-2011, 09:02 PM
Since I went efi and single wire alternator my harness is quite different now. For your car I wouldn't cut the harness, I would make jumpers to connect them together.
08-09-2011, 07:40 PM
Furious - what a difference! Fired the car up in the garage without the resistor (made a jumper) and she sounded even healthier then with it in... thanks for the tip. Found my manual and it said not to run it... dunno how I missed that the first time...
08-10-2011, 12:42 PM
Looks like you used the exact jumper I did when I first tried this before rebuilding the harness. I found a premade one in my toolbox, I'm guessing it actually was in the MSD box for this purpose.
08-11-2011, 07:47 AM
Actually I just threw that together with a spare piece of wire I had lying around. This car WOKE UP with the change from 9volts to 12volts to the box! Took it out for a test drive yesterday and 95% of my pinging at wide open is GONE! I'd been battling that since the car was put together... I thought it was a combination of too much compression (I'm at 10.5:1) and not enough timing but all along it's been the ignition... this is a whole new car to drive now!
Thanks again for the help!
08-16-2011, 05:09 PM
Interestingly there is an article on this in the Oct issue of Mopar muscle which came a few days ago. I cut the Mopar ignition harness off when I went to my MSD in the Duster and just went to ignition hot and the battery, not ever going back to stock.
08-16-2011, 08:38 PM
Could you scan it and post it? I just searched the MM site and couldn't find it.
08-17-2011, 04:03 PM
I am willing - but need our moderators opinion as I don't want to get us into trouble. If we scan and post without permission isn't this a copyright issue?
08-18-2011, 09:46 PM
No copyright issue... you own it and aren't taking credit for the copy. We posted scans from various Mopar mags on the old forum...
08-20-2011, 06:11 PM
I agree with Mike, I think its ok...
08-22-2011, 09:50 AM
OK I will post when i get a chance
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