Bob P. -- Ignition Switch Woes

[davids2toys]

MSD tech dept also recommends running the POS and NEG wires directly to the battery. Mine is not, but I may do it. It always scared me running before the battery shutoff because there is no way to cut the power to the MSD box in an emergency. Also jump starting or charging had me worried too. I suppose any welding would also be an issue. They said nothing could happen to the box unless the ign was on and juice was going to the small red wire. I guess i wasn't sold!
They also recommend running a ground jumper wire from the grounded head to the un-grounded head, I am going to do that for sure. I may even run another jumper to the block because of the aluminum heads.

[patrickt]

If your MSD box is mounted above the passenger's feet, where it is nicely hidden, then the easiest wiring method is to run the fat red wire through the firewall to the hot side of the 50 amp circuit breaker, the fat black wire should run directly to the passenger side cylinder head where you presumably have the battery's negative cable grounded. You should also be using the MSD Capacitor as it prevents a number of problems. It's called a Noise Filter but it's really just a big capacitor. Run the wires from the box to the coil down one side of the block and run the wires to the magnetic pickup down the other side of the block. This is a tried and true wiring method.

[davids2toys]

Originally Posted by patrickt

If you end up replacing the ignition switch, with an identical new one, there are three porcelain insulators between the terminals. The one that would normally be pointed directly down at the 6 o'clock position will likely interfere with the lip of the dashboard and it must be ground down in order to fit. Other than that, an ignition switch change out is about a fifteen minute job. Getting that little bezel off is the hardest part, but if you look at the two slots you can see how you would fashion a little makeshift tool to unscrew it.

Amazing memory you have there!!! Good info about the interference, I will be looking out for it. The one that is in there is a Standard US14 an has no interference. The one I picked up is the NAPA equivalent and looks exactly the same. Last night I ordered another US14 from eBay. I already have the bezel off and the switch is hanging waiting for me to replace it, I did notice when I was troubleshooting that the small MSD red wire terminal was not tight, I could easily move it with my hand, but I dont think it was loose enough to cause the car just shutting off problem. I am chalking that up to coincidence,.
I just went and checked out the old switch that is still in the car, you were right on the money, that insulator is ground down a lot!!! I will do the exact same to the new one and the one from, eBay when it arrives next week.
Thank you for the heads up!

[davids2toys]

Originally Posted by patrickt

If your MSD box is mounted above the passenger's feet, where it is nicely hidden, then the easiest wiring method is to run the fat red wire through the firewall to the hot side of the 50 amp circuit breaker, the fat black wire should run directly to the passenger side cylinder head where you presumably have the battery's negative cable grounded. You should also be using the MSD Capacitor as it prevents a number of problems. It's called a Noise Filter but it's really just a big capacitor. Run the wires from the box to the coil down one side of the block and run the wires to the magnetic pickup down the other side of the block. This is a tried and true wiring method.

Yes, all of that is exactly how I have it hooked up and I installed the capacitor 1 month ago, even though it has been on the shelf for 3 years...LOL
The only exception from your hook up is my fat red wire is connected to the other side of the circuit breaker, the ERA brown wire is connected to the other side and I am assuming this is the side you are referring to as the HOT side.Is this OK or should I hook it up with the brown wire?
Originally , the heavy neg battery cable from the battery went directly to the frame in the trunk (still does). The MSD neg wire and the jumper to the firewall were all that came off the bolt on the back of the passenger head. I guess the firewall wire was the assumed ground to the frame. A few years ago I ran a 10 gauge wire off that NEG lug in the trunk up to that same head bolt. So now off that head bolt I have 3 wires, firewall, MSD negative black wire, and neg from battery. I am going to add another wire from that bolt on the back of the passenger head over to the front of the driver head because there is no bolt hole in the back of the driver head.
My box is mounted under the glove compartment over the passengers feet. It is upside down and MSD tech told me because of this I need to drill 2 #30 holes in it so the condensation has a away out. I know I did this, but I just looked at it and there are no holes drilled in the ribbed side so I must have drilled them it the base of the box. Anyway, I did whatever they told me to do at the time. Sucks getting old, I can't remember anything anymore!!!

[patrickt]

I should have said to install it to the "protected" side of the circuit breaker. The MSD box draws about one amp per 1000 RPMs. So that if the circuit breaker is "blown" then no current will go to the box.

[davids2toys]

That sounds like the way I have it hooked up. Is that the way you have yours setup also? I know MSD does not like it that way!

Does that CB ever blow or wear out leading to malfunction? Is that an item I should carry in the emergency car repair kit in the trunk

[patrickt]

Originally Posted by davids2toys

That sounds like the way I have it hooked up. Is that the way you have yours setup also? I know MSD does not like it that way!

Does that CB ever blow or wear out leading to malfunction? Is that an item I should carry in the emergency car repair kit in the trunk

That's the way I have mine and the circuit breaker has never blinked in 15 years. Remember, having the MSD box's feed on the alternator side of the circuit breaker (the protected side) means that most of the current going in to the MSD box will not be going through that circuit breaker anyway, it will be fed from the alternator to the box, not the battery.

[davids2toys]

That is good news.

As I said, MSD does not like it going thru any switched, CB'S, or from the Alternator. They want it direct from the battery. I have to call them today anyway about proper rotor tang adjustment to dist cap center electrode and I will review this. So if I fed the the box from the unprotected side of the CB ( where the brown jumper wire is connected), that would be directly from the battery correct? Wouldn't the alternator be supplying the power when the car is running either way it was connected?

[patrickt]

Originally Posted by davids2toys

Wouldn't the alternator be supplying the power when the car is running either way it was connected?

Yes, the alternator is supplying the load of the MSD box whether the MSD box is connected to the top terminal or bottom terminal of the circuit breaker, but your box's load will also be supplemented by the battery as the wattage load of the MSD box changes. The current from both the battery and the alternator will be dynamic. The only real difference (other than a slight mathematical difference because there is resistance in a circuit breaker itself) is that when you have the MSD box connected to the battery side of the circuit breaker then the current from the alternator (less than 10 amps) is going through the circuit breaker. The opposite is true when you have it on the alternator side of the circuit breaker. But it's not really a big deal, so don't worry about it. And it's sure as heck not the cause of your car shutting down. The reason you usually see it on the protected (top terminal) of the CB, instead of down below on the terminal that leads to the battery, is because if for some reason that fat red wire shorted to ground you would have an electrical fire because the circuit breaker wasn't isolating the fat red wire's path to the battery.

[davids2toys]

Great point about the fat red wire grounding out unprotected! Yes, I know this is not my problem with the car shutting down

[patrickt]

The nice thing about "no spark" coming out of the coil wire, after you've replaced the coil a couple of times, is that it absolutely, positively has to be a limited number of issues. Either the MSD box is not getting turned on, or it is broken, or the distributor pickup is not sending the signal to collapse the coil's field, or the wires have crappy connections. That's it. It's got to be one of those. You're using the violet magnetic pick up wires, correct? Do you have the white wire going to a kill switch or just taped off? If that white wire is just stuffed some where that it can brush up against a ground, it will kill your engine.

[davids2toys]

Yes, using the violet pickup wires. white wire is capped but I plan on hooking it up as a kill switch in the near future. I was just on hold for an hour waiting for MSD tech. A Holley guy ended up taking the call because I guess they have the hours wrong. He did not know that much about the MSD side of things but he really tried to be very helpful. We got talking about hooking the box direct to the battery and the risk. He suggested and inline fuse right off the batter and then hook the fat red into it, that would protect it from roasting due to accidental grounding. He also suggested that running directly off the battery would insure straight DC volts unlike what would be coming from the alternator or a mixture. I will run this stuff by them tomorrow.
So is your box mounted upside down above your passengers feet?

[patrickt]

Originally Posted by davids2toys

So is your box mounted upside down above your passengers feet?

Yes it's mounted upside down over the passenger's feet, and the beauty of that capacitor is it allows alternating current to take a short cut through the capacitor and back to its source without heading in to the MSD box. The capacitor also buffers DC surges.

[tboneheller]

I had a problem with mine shutting off. It ended up being a large brown wire ( I think that was the color) had burnt in the multi pin connector that was inside the cockpit behind the center area of the dash. I think it supplied power to the AMP gauge or from the AMP gauge. It took me a few wrecker bills to find it because after the car sat for awhile until I could try to diagnose the problem, the car would start. Check that first. It was a CLEAR CONNECTOR that was in-line. Most likely the dash harness connector. This occurred about 18 years ago. My car is ERA505. Hope this helps.

[davids2toys]

Originally Posted by patrickt

Yes it's mounted upside down over the passenger's feet, and the beauty of that capacitor is it allows alternating current to take a short cut through the capacitor and back to its source without heading in to the MSD box. The capacitor also buffers DC surges.

So I am assuming you did not drill any holes in the base?

[davids2toys]

Originally Posted by tboneheller

I had a problem with mine shutting off. It ended up being a large brown wire ( I think that was the color) had burnt in the multi pin connector that was inside the cockpit behind the center area of the dash. I think it supplied power to the AMP gauge or from the AMP gauge. It took me a few wrecker bills to find it because after the car sat for awhile until I could try to diagnose the problem, the car would start. Check that first. It was a CLEAR CONNECTOR that was in-line. Most likely the dash harness connector. This occurred about 18 years ago. My car is ERA505. Hope this helps.

You are saying the car would still start?

[patrickt]

Originally Posted by davids2toys

So I am assuming you did not drill any holes in the base?

The MSD box has mounting hole flanges on the corners. You do have to have bolts coming down through the aluminum behind the dashboard. Here's a pic to show you what I mean. The plug with the two yellow wires goes up to an adjustable rev limiter that I have mounted in the glove box. The purple wires are the pick up, and the orange wire is the tach feed.

[Moriarty]

Originally Posted by tboneheller

I had a problem with mine shutting off. It ended up being a large brown wire ( I think that was the color) had burnt in the multi pin connector that was inside the cockpit behind the center area of the dash. I think it supplied power to the AMP gauge or from the AMP gauge. It took me a few wrecker bills to find it because after the car sat for awhile until I could try to diagnose the problem, the car would start. Check that first. It was a CLEAR CONNECTOR that was in-line. Most likely the dash harness connector. This occurred about 18 years ago. My car is ERA505. Hope this helps.

I had the same problem (ERA 412). Pics and details in this thread:
Electrical gremloins??

ERA sent me a nice fat connector to replace it with.

[patrickt]

Sometime before my car's birth (#732) ERA adopted high amperage connectors for two connectors that had previously been in one of the multi-pin connectors. Just do a search in the wiring instructions for HIGH-AMP and you'll find it. I don't know when they did it, but you can't miss them when you go under the dash. They're big red connectors.

[davids2toys]

Originally Posted by patrickt

The MSD box has mounting hole flanges on the corners. You do have to have bolts coming down through the aluminum behind the dashboard. Here's a pic to show you what I mean. The plug with the two yellow wires goes up to an adjustable rev limiter that I have mounted in the glove box. The purple wires are the pick up, and the orange wire is the tach feed.

I was not talking about the mounting holes , I am talking about adding small ventilation holes because with the box mounted upside down, water could collect on the finned side which would normally be the top. They sold me that if mounted on it's feet, the bottom is not sealed so water could escape, being upside down, the condensation cannot escape