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Discussion Starter · #1 ·
5 years ago I did a frame off resto on my 69 Camaro. MSD 6AL Ignition, C130 (2 wire) Alternator, 4 Pin GM HEI distributor all wired as per MSD install instructions for GM 4-pin Module as on page 16 of MSD instructions, no diode was ever needed in the "GEN" light circuit. For the last 5 years I've never had Run On. Went racing Wednesday night and now I have run on. Turn key off and engine keeps running, "Gen" light comes on. Only 2 ways to shut off is to trip my Kill switch (Theft Deterrent switch on white wire as shown on page 6 of MSD instructions), or to put the trans in reverse. I have a 200-4R trans with a B&M shifter which uses a neutral safety switch. The only relays I used are for the head lights and I brought power directly from battery + as per relay instructions. So why after 5 years do I now get Run On????? Why does it shut off when trans goes into Reverse? What am I missing here?
 

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Discussion Starter · #2 ·
I'm still stumped by this run on issue. Should I post in a different forum to get more views? Maybe the General Tech Forum, or would the moderator just move it back to Electrical? Kind of frustrated.
 

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Now everett replied to a similar thread a week or so ago....something like the feed on the alternater should be conected to a line that is thru the ign so is off when the ign is off...
Run a forum (not the bloody usless site google) seach .
 

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Discussion Starter · #4 ·
I've already run the forum search, there are no posts with this same issue. I already made all the changes that are described in the posts from the search when I built the car 5 years ago.
 

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John - stuff like this doesn't just happen. Either something was effected by pre-race wrenching or something has gone bad, come loose etc. Was there any issue with shifting to reverse before this started?

I'd start at the key switch and look for battery on the ign lead when the key is off. Does the engine run if the key is removed? Next look at your neutral safety switch, will the car start in park and neutral? Does any other gear position shut it down? After that look for a broken or shorted wire under the hood near your ignition box and dist.
 

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I bet u used the google search and not the site search which if u scrolled down appears
"SPECIALTY SEARCH"

seach parameters running on and for posts by everett showing posts.

The post them came up the 8th down the 1st page
http://www.camaros.net/forums/showthread.php?p=1464138&highlight=running#post1464138

The site Admins should at least put the "SPECIALTY SEARCH" above the google or dump the google altogether
Too often ppl are saying "i did a search and cant find it"
 

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Did the diode go bad? Should be a cheap easy part to check with a multimeter or just replace it from radioshack.

Jereme
 

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John, good to see you back on the board... hope things are back to some normalcy for you there. Not sure about your 'run on' issue but Dennis' thinking seems logical... something happened, a short in key switch or wires rubbed or? Between Ev and others hope you find it. Give a shout next time you come to Brd.
 

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You said you have a kill switch, leave the MSD disconnected for a few minutes as so it can lose memory.

The MSD, with the red wire (small, ign wire) disconnected, for all practical purposes, is or should be a dead box.

Either there is 12v+ still supplied to the red ign wire with the switch off, or there is an internal path in the MSD box (short) from the big red batt power wire to the ign wire circuit (defective MSD box)


With the switch off, and car running, disconnect the red ign wire. If it stays running, replace box.
 

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Discussion Starter · #10 ·
Hey Guys, been gone for a while. I can drive the car OK for now, just have to trip the kill switch to shut down so I'm waiting for cold weather to work on it.

Chops..I'll try your idea.

Click...good to hear from you too. A good friend moved to Brnd this summer so I'll get there more often now.

RedJet...Haven't checked the diode yet...I'll do that in a few weeks when it gets cold.

Steptoe..I used the "Search this Forum" search in the Electrical and Wiring Forum.

DjD...I agree something happened, it has never done this for the past 5 years. It started while at the track in Brainerd. This was a street racing night (everything had to be street legal) so the only wrenching I did was to put my Hoosier DOT slicks on, no wrenching anywhere else. Engine runs when the key is removed and only shuts down if I trip the kill switch or put the trans in "R" with the ign switch turned off. It keeps running in drive with key off. Only starts in Park or Neutral.

Thanks for the ideas.
I'll find it, it'll just take some time with a 12 pack and a cigar this winter. Like most electrical problems..not complicated to fix...just takes time to diagnose.
 

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John is there a neutral safety switch in that 200r ? check that out too.
 

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As chops suggested, turn ign off and disconnect ign wire to box.
If it quits running, ign switch out of adjustment on column - still supplying ign voltage. Test light or meter will tell the story.
If it still runs, box has internal fault.
 

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Discussion Starter · #14 ·
Hi Guys,
Well it's winter and I'm finally getting around to tracking down my "run on" issue. To recap the problem..after 5 years of no problems I now have a run on issue. Here's the deal: I have MSD 6AL, HEI distributor, a 100 Amp internal regulated Alternator. While racing at BIR last summer I developed a run on problem. When I turn the key off & pull the key out the engine keeps running. It will run in Park, Neutral, Drive, 3, 2, & 1 (200-4R Overdrive), however if I put it in Reverse it kills. It will only start in Park & Neutral so the Neutral safety is working. I also have a kill switch which grounds the white MSD wire to ground. The kill switch will also kill the engine.
So, following the suggestions in the posts above I disconnected Batt power to the MSD with the ignition off and engine running. The result is the engine kills. So the MSD box is OK. Also, a meter shows no voltage at the 12V supply wire to the MSD with the switch off, so the switch is OK. However, the 12V supply wire to the MSD shows almost 7 volts when the engine is running with the key off, so it's getting power somewhere with the key off. So I must have the "diode" problem. Would there be that much voltage caused by a bad diode? Problem is I don't remember putting the diode in when I installed the MSD (memory goes first ya know). Could my Alternator have an internal diode? Its a Power Master 17294.
Thanks for the help...cruising weather coming soon :)
 

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Take the alternator belt off of the engine & start it.
Does it now stop when you turn the key off? This will prove the feedback is from the Alt & not something else.
 

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All alternators have diodes, that is how a/c voltage is coverted to d/c voltage. You said that you have 7 volts on the 12v supply wire after shutting the key off, is this the wire coming from the ignition switch or does it come from somewhere else. The source of this 7 volts must be your problem.

Dan E.
69 ss396 4spd. 4.10 posi. x66 coupe
 

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Discussion Starter · #18 ·
Pulled the Alt belt. Engine shuts down with the key. 12V power to MSD comes from the switch. If I remember right It's the wire that used to supply the resistor wire before the HEI. I'll have to unwind the wrapping and see where I put the diode. Funny I still don't remember putting one in.
 

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John, next trip to Brd. give a hollar for coffee :)
 

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Discussion Starter · #20 ·
Yes, definitely. Sorry it's been so long. Life returns to normal rather slowly after divorce. Believe it or not I even lost interest in the cars for a while. Seems like my old interests are returning. I'll give you a call.
 
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