Fried MSD Iginition Box

[TimG427]

I’ve got a 468 Shelby aluminum block in my Cobra that was rebuilt by Keith Craft in 2009, this is CSX4188. The engine and car run great. Last weekend I turned on the ignition and smoke billowed out from the ignition box under the dash. I cut power and removed the box, it smells of burnt wire and is definitely fried. All other items seem to work well with the box out, fuel pumps, fan, lights and starter all perform well. The box is a MSD Digital-7 programmable #7530. I’ve ordered a new one, #7530T that appears to be a direct replacement. Can you offer any advice on what if anything I should do when I install the new ignition box? Will this need to be programmed before installation?

[Keithc8]

I would re-check the tining on the engine when I got things hooked back up. I would check to see if there is anything else that is burnt. The box will have some setting in that might need to be checked and set. There are a lot of options with it that you will not use and some that you might want to use.

Thanks, Keith Craft

Originally Posted by TimG427

I’ve got a 468 Shelby aluminum block in my Cobra that was rebuilt by Keith Craft in 2009, this is CSX4188. The engine and car run great. Last weekend I turned on the ignition and smoke billowed out from the ignition box under the dash. I cut power and removed the box, it smells of burnt wire and is definitely fried. All other items seem to work well with the box out, fuel pumps, fan, lights and starter all perform well. The box is a MSD Digital-7 programmable #7530. I’ve ordered a new one, #7530T that appears to be a direct replacement. Can you offer any advice on what if anything I should do when I install the new ignition box? Will this need to be programmed before installation?

[tnlprt]

Send the old box to MSD and let them tell you what happened to it

[Blas]

If the box is mounted up-side-down; COuld water from rain or washing the car have gotten in there? A smoking box is unusual. A loose ground connection, connector, etc. can caus a surge, but that usually only pops the internal fuse on the unit. Test your coil before reinstalling the new unit.

[TimG427]

I thought of the water issue, the car really doesn't get wet. Testing the coil is a good idea. The box cost $900, so I don't want to go through too many at that price.
I can check to see if MSD would diagnose things, but after opening it up I see the entire box is sealed in a rubber/plastic.
Any other replies would also be helpful.

[kevins2]

Hi Tim,

I have an ERA kit on order and am also planning on using MSD. After hearing about some failures, I Googled MSD problems and see there are lots of failures out there. I brought this up to the folks at ERA and they indicated that a lot of the failures are caused by current spikes. They modify their wiring harness for MSD customers to include a capacitor to protect from spikes and say that they have had no issues with MSD boxes. I don't have the kit yet so don't have the benefit of looking at the harness or any experience yet, but thought that might be worth mentioning. Maybe someone with experience with this will chime in with more details.

Regards,

Kevin

[Dangerous Doug]

I would take a good, long look at the wiring schematic, and then check the inputs/outputs for shorts before I put another $900 box in it. tnlprt up above had a grand idea to send the box back to MSD for analysis. It's long past the warranty, but at least they can narrow down the root cause to something internal to the box or externa---meaning your wiring harness.

Good luck,
DD

[Dwight]

MSD will rebuild it for you. The 6AL box they charge $80 to rebuild.

Check your alternator. It could go bad and put out more than 14 volts which will fry your MSD. And your coil and your magnetic pickup.

Been there, done that.

Dwight

[Rick Parker]

I have used the same MSD 6T box on my car since 1988. They HATE vibration and will shake themselves apart if exposed to it constantly. They have available rubber Lord mounts for each corner. They help isolate the constant vibration these cars inherantly have and transmit to anything attached to the chasis or bodywork, they work well and they are available also at some hardware stores, although not under the MSD name.

[JLip]

I was driving and noticed the engine misfiring for a short period of time then smoke rolling out of the tachometer. The car ended up dying in the middle of the road. Found the ground cable from the battery came loose from where it was mounted to the frame which shorted out the tach and blew the MSD box.

I had to get a new tach and MSD fixed the box. It was obvious the cable came loose because the lug was broken so I replaced it.

All works like a Champ! I also updated my AAA card for better towing distance!

[TimG427]

Would the alternator issue arise even if the car wasn't running? I turned the ignition on and the problem happened.

[Dwight]

I don't know. Sometimes electricity is a black art.
But the over voltage could have degraded some of the components in the box and it failed when you crank the car.
We have an old school local shop, that test our starters and alternators for free. You can test it yourself with a meter. Test the battery before you crank the car and after. You should see an increase of 1 to 2 volts. If you have more than 14 volt then remove the alternator and have it checked.
Remember each NASCAR race car has two MSD boxes!
Heat, vibration and over voltage, (currant spikes) will kill electronic components.
Dwight

[tirod]

Losing an engine ground means all the current will go thru the next available one. I had issues with that in a '66 Mustang, it got to the point where I couldn't turn it off with the key, I had to dump the clutch on it securely parked. It wouldn't start properly either, finally just laid on the key and fried the clutch return spring smoking. 250 amps will do that.

Everybody services the battery cable attachments, nobody keeps the negative ground on the block maintained. Choose where you want to let 60 to 250 amps to return. We need to treat it better than the battery clamps, more might be at stake.

[TimG427]

I hooked up the new MSD box after much checking of the wires. All seemed fine with the wires and that was confirmed when I connected the new box. The box is set at "0" and the timing is good on the car. It runs like a champ...........

[twobjshelbys]

I went through 2 of these before I sold it. Don't know what took them out. First time it just stopped, second time I was trying to jump start with a dead battery.

[Gaz64]

The new 7530 will be need be programmed with the same file you had in the original 7530.

DO NOT mount it upside down, even in the cabin, moisture in the air will get to the circuit board.

All MSD ignitions can operate from 8 to 16 volts.

[RICK LAKE]

Tim G 427 Tim, I know from personal experience That the old "7" boxes had problem when they first came on the market. Some people let the smoke out of them. As others have said, running heavy gauge wire for the power feeds to the box is very important. I run 10 gauge directly to battery and multi ground straps to chassic, "2" to engine block, and all other ground connections of the electric system. I have "4" with start washers that cut into the metal when crushed. Trying to start a car with a weak battery or jumping it with a dead battery will burn out any MSD box. I don't know why but have seen this happen many times. If jumping give the car 5-10 minutes before turning to start. A full charged battery should be in the 12.5 volts and have a min of 500 CCA load. Mini starts will crank over a motor with 7.9 volts. This is not enough for the MSD box and will cook it. Weal connections again have too much resistance and cook the box. Keeping a trickle charger on the battery is a good idea. As far as mounting a MSD box, any where is fine. I have mine upside down under the glove box and have not had a failure in 14 years with a 6AL. I smoked the first one because of welding on the car. All systems where off but the battery was not unhooked. Turned key on and SMOKED. Buy a tube of clear silicone and dye electric grease and coat the connections with this. Tube of clear is to seal the box from moisture. I do the bottom of the box seals and terminals going into the box. Coat the connections with thin coat of grease. These boxes make alot of heat, try and mount it where you get a good air flow to it. Use a Tee and run the foot box hose to it. They also sell small fan boxed to mount and blow air on the cover. The cover is a heat sink. This helps extend the life of the box. I don't know if this helps but, after car has been sitting for a week or so, the battery will drain a little. Starting the car will spike the electrical system. There is not alot you can do about this. If battery is fully charged this helps. Rick L.

[TimG427]

Thank you for the helpful ideas, guys.

[kevins2]

Originally Posted by RICK LAKE

Starting the car will spike the electrical system.

Back in post 6, I wrote that ERA installs a capacitor in their wiring harness to protect the MSD box from voltage spikes. Seems worthwhile, but nobody commented on this. Any experience with that helping?

Regards,

Kevin