MSD and battery drain..?
Thread Starter
Burning Brakes
Joined: Oct 2002
Posts: 914
Likes: 14
From: Aberdeen, Scotland
MSD and battery drain..?
Hi,
I just fitted, or rather had the shop fit a new MSD to my LS-5's stock, recurved system. Now I have a serious battery drain. To the point that I am not wanting to drive the car very far.
SO .. I have ordered a battery dsconnect but this is not fixing the problem, just a band-aid. Has anyone had this with MSD before? Can I have a bad box? I heard that their quality is not as good as it used to be.
carbster09
I just fitted, or rather had the shop fit a new MSD to my LS-5's stock, recurved system. Now I have a serious battery drain. To the point that I am not wanting to drive the car very far.
SO .. I have ordered a battery dsconnect but this is not fixing the problem, just a band-aid. Has anyone had this with MSD before? Can I have a bad box? I heard that their quality is not as good as it used to be.
carbster09
Melting Slicks
Joined: Jun 2001
Posts: 2,340
Likes: 2
From: Moro IL
Most of the aftermarket ignition boxes normally come with a bypass harness to take the box out of the igntion system loop. I don't remember if the MSD systems did or not but I know the Mallory units do. Try bypassing the unit and see if the drain goes away.
Pat Kunz
Pat Kunz
Le Mans Master
Joined: Nov 2003
Posts: 5,771
Likes: 694
From: Maryland
St. Jude Donor '05, '09, '15
I put an MSD 6AL on the 65 last summer. I have had zero problems. I'd bet they have it hooked up wrong. Go to the MSD site http://www.msdignition.com/1ignitions.htm select on your ignition box. The installation instructions are there on the left.
Burning Brakes
Joined: Jun 2005
Posts: 769
Likes: 0
From: NorCal 71 Lt-1
Looking @ the wire layout my guess would be that they could have hooked the smaller gauge red wire to "hot" all the time source instead of the ignition key source. Trace the red wire up to where they tapped in. With the ignition off, use a test light to see if your getting power through that wire. You should not be. Good Luck!
Pro
Joined: May 2005
Posts: 745
Likes: 0
From: Miami Florida
b4 you go looking for a problem check the output of your alternator. msd boxs pull alot of current to produce the spark they do. it could be that b4 your alternator was doing the job but now too much is going to the box and not the bat.
Safety Car
Joined: Aug 2000
Posts: 3,711
Likes: 43
From: San Antonio TX
The shop that did the install screwed something else up. It's not the MSD box. The MSD doesn't need to be hooked to a keyed power source since once the cap it charged, the box pulls no more juice which is why it's normally connected to a constant hot. Moving the power source will not solve your problem. If you want to test this theory, just do a simple test with a DVOM between the box and the power souce. If it's the problem, it will show an amp draw.
