Pertronix Question for AQ131

[Fishermark]

I am installing a Pertronix Ignitor II (Part #92842) in my 1990 AQ131. I have installed several of these in other boats I have owned and am happy with the results - but so far my experience is with Mercruisers.

I want to eliminate the resistor and need to verify what i think I understand....

On a Mercruiser the resistor is the wire itself going to the positive side of the coil which I simply eliminate. On this Volvo it appears the resistor is down by the alternator. Is that true?

If that is the case, can I simply remove the resistor and attach a wire straight from the alternator to the positive side of the coil?

Here's a pic of the resistor down by the alternator:

Here's the wiring diagram: (THE RESISTOR PICTURED ABOVE IS PART 22 IN THE DIAGRAM BELOW).

And a closer look....

 

[radar224]

My question is why would you?
I've installed the pertronix on my q131 without removing the resistor wire without problems.
I would measure the voltage at the coil first before removing the resistor. In my case I had the full required voltage.

It was a great upgrade btw. Well worth the money.

 

[Fishermark]

Pertronix recommends removing the ballast resistance or resistance wire and changing the coil to one not requiring external resistance. Like I said, I know Mercruiser uses a resistance wire that is simply bypassed. The unusual thing about the wiring diagram above is I do not see how it is supposed to work. I am certainly no electrical engineer, but with the wiring harness splitting at connector #7, it looks like the coil is already receiving the full 12 volts. I don't see how the resistor coming from the alternator would affect anything.

I guess my question then would be: is the wire coming from connector #7 actually leading to to alternator as a sensing wire? In that case, the resistor would have something to do with the alternator and would need to stay in place.

BUT - if that is the case, then that would make the other wire leading from #7 down to the positive side of the coil the resistance wire. That would make sense... but I would think that would be identified as such on the wiring diagram.

 

[bruceb58]

From the diagram, the coil is already receiving full voltage and has nothing to do with that resistor.

 

[Fishermark]

It does indeed look that way Bruce... but how and why? This is a points system. Doesn't that ALWAYS mean some resistance in the system somewhere?

 

[bruceb58]

Resistor could easily be in the coil.

 

[radar224]

I had full voltage at the coil when I installed the pertronix. I had a close look at he wiring diagram and found, as Bruce mentioned, that there was no resistance wire between the battery and the positive side of the coil.
I confirmed this by placing a digital voltmeter on the could terminal both while turning the engine over and while running.

 

[bruceb58]

The best way to confirm it is to put a jumper from the negative side of the coil to ground or close the points and measure the voltage at the positive side of the coil to ground.

 

[Fishermark]

It was a great upgrade btw. Well worth the money.

So Radar - did you keep your original coil? Welcome aboard by the way! ;-)

 

[bruceb58]

Out of curiosity, why are you changing from points? Because of the Pertronix reliability issues, I never switched when I had multiple boats/engines with points.

 

[Fishermark]

I've used the Pertronix for years on various boats and have not had any issues. I am familiar with the various pros and cons... but my experience has been good. To me the advantage of the electronic ignition outweighs the points system. (Plus the Volvo stuff is expensive! Even for basic tune up items).

Just as an aside - I HAVE had issues with the Hot Spark brand of electronic ignition. They are very inexpensive... (something like $50)... but I had trouble with the one I installed on my last boat. Ended up taking it out and going with the Delco EST setup. This was in a Mercruiser 3.0 liter. Now THAT is a good system.

 

[bruceb58]

Agreed. I have an EST distributor ready to go into my 7.4L Volvo to replace the complicated system that is in it which was only used for one or two years. Being proactive.

 

[radar224]

Fishermark, I did change the coil also to the pertronix flamethrower. Since the ignition parts were slow to ship I ran the points for several weeks with the Pertronix

I had a few issues with this engine.
The Volvo had been in storage for 4 years and everything was plugged solid in the carburateur.
After doing a rebuild on the carb it was still very cold blooded so I decided to tackle the ignition.
Also changed the timing belt and buffed the belt sprockets.

After all the work the engine is running great and idles the way it supposed to.

Thx for the welcome! This is a great forum.

 

[bruceb58]

After doing a rebuild on the carb it was still very cold blooded....

That's actually a common problem with these Volvos and not an ignition issue.

 

[jeffnick]

Just make sure you don't leave the ignition on when the engine is not running.