MSD analog relibility; any ideas?????

Dave,

I do appreciate the quick reply RE this MSD unit problem.

Your comment, "After taking a quick look at the installation instructions I don't believe for a second that the Accel Coil caused the unit to fail." made me laugh, only becuase the TWO MSD techs I talked to couldn't even agree on whether it was the coil that had killed the 5462, or the 5462 that had killed the coil....

I have to tell you, I made SEVEN consecutive phone calls to MSD about how to wire this thing up before I actually DID it (successfully), mainly because they couldn't decide whether my stock Mopar (1974) OEM electronic distributor used "magnetic pickup" or "Hall effect" technology. Every time I called, I got a different tech, and a different answer. I am NOT kidding. The first two told me that I'd have to piggy-back this 5462 on my orange box; the third told me that they were crazy (paaraphrased), and to wire it up like the instructions showed (no orange box), and when I caled back, two days later, I was told that he had quit, after 16 years with the company.

I don't blame him...

I eventually had to call a friend who is a Mopar line tech to find out that Hall effect distributors have THREE WIRES... mine has two, of course, because it's a magnetic pickup unit.

Anyway, I'd BET you're right about the Accel coil being okay, and not being the cause of that transistor's failure in the 5462.

I am concentrating on adding more ground straps... Hope that will preclude more unwanted transistor tragedies.

Thanks a lot for your advice!!!

Since you're an engineer, you might be able to answer this question, while I have your "ear":

My tach is an el-cheapo Summit unit that uses the signal that is picked up on the negative side of the coil.

The "techs" at MSD told me that this 5462 sends 100+ volts to that "minus" coil terminal. I know I heard them right... two of them told me that; something about minimizing "rise time" in the coil.

That doesn't concern me.

This tach has always worked well.

I'm wondering whether the 100+ volts might have a shock for it that it won't survive... so, I haven't hooked it up... yet.

Do you have any thoughts on that?

If you do, I'd appreciate your opinion.

Thanks if you do; thanks if you don't.

~I~ have NO CLUE... us usual.

Bill

Bill, in Conway, AR.