Pertronix ?

[CV16]

My dad has a 1980 Mercruiser 228. At some point, somebody added the Pertronix unit to the boat. We've been having problems lately. After reading quite a few posts on here, I ended up finding that I think the unit is bad. With the key to the on position, I only get 3v at the coil, or the resistor. The volts increase when cranking, and sometimes when I quit cranking, it'll read 11v, sometimes 9v. In trying to find out why, I find that if I take the neg wire from the Pertronix off of the neg post on the coil, I get 12v where it should be. All other wires seem to change nothing. If I run a wire from the pos battery post to the pos coil post, it starts and runs great. I took the unit off and tested for resistance from red wire to black, I got nothing. Then I put the red wire on the pos battery post and got 12v from the black wire on the Pertronix. Before I go and spend another $100 to see if this is it, does it sound like the Pertronix unit is bad?

 

[thumpar]

Re: Pertronix ?

Sounds more like a wiring problem. The voltage should only change to the coil when you are cranking. The pertronix should also see a constant 12v from another source than the resistance wire.

 

[stonyloam]

Re: Pertronix ?

If it runs then the unit must be OK. You have a wiring problem. First off the Petronix needs a full 12V on the red wire to work properly. What do you have for a coil, stock or flamethrower (petronix)? Sounds like you have a resistance wire or resistor in the circuit. When you are starting the resistor is bypassed and battery voltage is applied to the coil +. If you have a purple wire from the choke to the coil, make sure it is a clean tight connection. If the petronix red wire is attached to the coil, remove it and attach it to a 12V source from the ignition switch. You could just use a jumper to the battery to test it. That should get it to work. You should have about 8V to the coil with the ignition switch on. Battery voltage when starting. Good luck.

 

[CV16]

Re: Pertronix ?

It only runs when I run a wire from the battery to the coil. The pertronix was on the boat when my dad bought it and it is all wired the way the instructions say. I cleaned all contacts and bought a new(stock) coil to replace the flamethrower. I have the right voltage everywhere right up to the point of putting the black wire from the unit onto the coil. That's why I'm thinking the pertronix is bad. Why would I have good voltage everywhere until that wire is hooked up?

 

[stonyloam]

Re: Pertronix ?

Red wire on coil +, black wire on coil - right? Your Flamethrower coil, was it a Flamethrower I or II? If the red wire is connected directly to the coil + you do not have the correct voltage for the Petronix module. The reason it runs when you hook up the coil to the battery is that when you do that the Petronix is getting the full 12V it needs rather than the reduced voltage through the resistance wire. Try this: Put the flamethrower back in. Wire the Petronix red +, black - and run a wire directly to the coil + from the battery and try to start it. If it runs, then all you have to do is bypass the resistor wire and provide a full 12V from the ignition switch to the coil +. Or as an alternative, remove the red wire from the coil and connect it directly to the battery + and give it a try. I am not sure about what the voltage readings should be, but if the module were bad it seems like it would not run at all.

 

[CV16]

Re: Pertronix ?

The red wire from the pertronix has never been put on the + coil. The pertronix is getting it's voltage dirrect from the ignition switch. I am not adding this, it's been on there for years, longer than we've had the boat. I have the instructions and it is installed properly. I can run a wire from the battery to the coil and it will run fine. If I take that same wire and put it where the pertronix gets it's power at the ignition, the volts drop right back to 3-4 at the coil and at the resister. When I take the - wire from the pertronix off of the coil, all my volts read correctly, that is why I feel the pertronix is bad. I took it off and put the red wire on the +battery post, I get 12v comming out the black wire then. Should it be that way or not?

 

[Raystownboater]

Re: Pertronix ?

You're actually answering your own question. If the pertronix were bad, it would'nt run no matter how much voltage is put to the coil. The fact that it runs when you put 12v to the coil should tell you that you have a wiring issue. The one thing you need to watch out for is leaving the key in the "on" position without the boat running. I talked to the techs at pertonix and they told me that is the quickest way to "kill" the unit. I went through the EXACT same problem with the pertronix and flamethrower setup and after a quick rewire, I had no more issues.

 

[stonyloam]

Re: Pertronix ?

I am not sure what the voltages should read, but I think your problem is with the purple wire going to the coil. It is not delivering enough voltage to the coil. The fact that if you apply 12V to the coil + it will run is the indicator. I will bet that if you remove the purple wire and attach the red Petronix wire along with its 12V source to the coil it will run. This would only be a test, because I do not know if your coil needs a resistor in the circuit.

 

[haulnazz15]

Re: Pertronix ?

You're actually answering your own question. If the pertronix were bad, it would'nt run no matter how much voltage is put to the coil. The fact that it runs when you put 12v to the coil should tell you that you have a wiring issue. The one thing you need to watch out for is leaving the key in the "on" position without the boat running. I talked to the techs at pertonix and they told me that is the quickest way to "kill" the unit. I went through the EXACT same problem with the pertronix and flamethrower setup and after a quick rewire, I had no more issues.

If you use the Pertronix Ignitor II, the unit will shut itself off if the key is left in the "on" position for an extended period of time.

 

[CV16]

Re: Pertronix ?

The wires are all good contacts. The only time my voltage drop is when I connect the - from the Pertronix to the coil -. I'm just going to buy a new one and see what happens! I don't see where any other wire could be the problem if it only happens when the pertronix is hooked up. I hate electrical issues, and this is why. If this doesn't cure it, I know where there will be a 1980 22' Silverline Nantucket for sale!

Does anybody have a Pertronix unit handy that could just check if they get 12v on the black wire when the red is given 12v? I have the feeling that the unit is shorted out.

 

[RogersJetboat454]

Re: Pertronix ?

I'm just going to buy a new one and see what happens!

I have the feeling that the unit is shorted out.

I have a feeling you will have a spare pertronix unit on hand afterwords. As others have stated, your engine probably isn't going to run if the unit is "shorted". Voltage is not the end all to beat all when doing electrical testing. You also need to be sure that the wires in question are able supply the amperage needed for everything to work. Wires that are internally corroded, partially cut, have bad terminals, or even bad contacts in the ignition switch may be able to supply 12V under no load. I can cut a wire down so it only has 1 strand remaining. It will be capable of providing 12V, but won't be able to carry any amperage.

Another thought.... Why not call Pertronix tech support? "Call our tech line (909 599 5955)"

A final thought...
If the pertronix unit truly turns out to be shot, why not upgrade the distributor all together?
The pertronix only subtracts the points from the equation. It does not replace the mechanical advance that's probably either worn out or frozen.
For a couple hundred more bucks, you get a complete ignition system that's superior to a worn out retrofitted distributor;
http://www.michiganmotorz.com/delco-voyager-marine-electronic-distributor-p-140.html

 

[Raystownboater]

Re: Pertronix ?

If you use the Pertronix Ignitor II, the unit will shut itself off if the key is left in the "on" position for an extended period of time.

Unfortunately I was using the Pertronix I and I was assuming he was also. Better safe than sorry.

 

[Raystownboater]

Re: Pertronix ?

It only runs when I run a wire from the battery to the coil. The pertronix was on the boat when my dad bought it and it is all wired the way the instructions say. I cleaned all contacts and bought a new(stock) coil to replace the flamethrower. I have the right voltage everywhere right up to the point of putting the black wire from the unit onto the coil. That's why I'm thinking the pertronix is bad. Why would I have good voltage everywhere until that wire is hooked up?

Im not trying to beat a dead horse here but if the engine runs at all, the Pertronix is NOT the issue and Pertronix tech support will tell you the same thing. You have a wiring issue that needs addressed. If you look at Pertronix.com, you can download the installation instructions that tell you the black wire goes to the - side of the coil and the red wire goes to the + side of the coil. If you have the disposable income, I guess you could buy a new Ignitor but just like Rogersjetboat said, you're going to end up with the same problem and two ignitors to choose from

 

[stonyloam]

Re: Pertronix ?

Have to agree, a new Petronix will not work any better than the old one unless you fix the wiring IMHO.

 

[CV16]

Re: Pertronix ?

OK, I took all you guys advice and just went and ran new wires everywhere in there. It runs great and I have the proper volts where it should be. I tried to contact the tech support, they called me back as I was getting the last wire screwed into place. Must have been a busy day for them. I am still baffled about why the volts would drop only when the - from the pertronix was connected, but it doesn't do that now. We'll be fishing in the morning now, dad is a happy guy, for today anyway!! Thanks for being here for me once again. Next time I'll just do what I'm told on here. I don't think I've gotten any bad advice on here yet!

 

[tigger3650]

Re: Pertronix ?

I seem to be having the same exact problem with my 140. It is wierd how this just starts (or in regards to the motor doesn't start) one day out of the blue. I read all my voltages and am puzzled:

I disconnect all wires from the (+) side of the coil, I have a purple-ish wire from the choke, a purple-ish/ red-ish wire from the ignition switch, and a pink w/ yellow stripe to the starter and a red wire to the prtronix ignitor.

With the key "on" I get 12v from the ignition wire to ground.

When I hook all the wires back up, starting with the ignition wire, I keep 12v until I hook up the red wire for the pertronix ignitor. When I hook it up to the coil, voltage drops to 4v.

I jumped a wire from the (+) of the battery to the (+) of the coil and vroom, fires right up. Pull the jumper off, motor dies.

I am going to run a jumper from the ignition key to the coil tomorrow and see if this cures the problem.

Any other suggestions?
-Mike

 

[Don S]

Re: Pertronix ?

Welcome aboard tigger, You will get better results if you start a new thread rather than hijacking someone else's old thread with a completely different engine than what they have.

 

[tigger3650]

Re: Pertronix ?

Welcome aboard tigger, You will get better results if you start a new thread rather than hijacking someone else's old thread with a completely different engine than what they have.

Thanks Don. I will repost.