That's exactly how mine is wired.

Kevin

 

It should read 12V with the key on. When you start the truck, and if you have a resistor, it will show less, indicating that the resistor is working.

Joe

 

Thanks Joe!

From that diagram, looks like you have it hooked up right. They show the oem ballast with the starter bypass so they must know it ain't getting 12v when running.

Question, does your pickup or bracket have any adjustment for moving around it's circumference, sort of like advancing or retarding it? Wondering if maybe your rotor isn't phased well with the cap.

Barry

 

Like Joe said, it will read 12 volts with the engine off, check it with the engine running. Yours should have a stock resistor wire to the + side of the coil from the ignition switch that drops the voltage to the coil when there is a load on it - engine running.

You can do a quick and dirty check to verify if the voltage is the problem: Find a piece of insulated wire and connect it to the + side of the battery. Then pull the red wire from the pertronix off of the coil and leave the one from the ign switch on the coil+ terminal. String the hot wire from the batt over to the red Pertronix wire (away from moving parts) and connect the two. Then quickly jump in ad fire it up. If the problem is gone and you can time it back without problems then you have nailed it. If it works then, then you can do the permenant hook up to the back of the ign switch and all is well. Of course you need to do that anyway, but it will tell you if that is what is causing THIS problem. Oh, when you shut it down dissconect the hot wire right away or you can damage the Pertronix unit if the distributor "parks" in the wrong place.

Hope this helps a little - Hal.

Oh, P.S. - williamwilliam, nice looking SW! My '67 SW has the same stance. I'm running dropped front beams, a built 390 and C6. I'm in the middle of paint right now with it.

 

Hey Joe, I think you have your Crane XR700 hooked up right. It shows that you need to use the ballast resistor, (or resistor wire in this case) on the XR700. Hooking it straight to the coil should be fine as you get the dropped voltage there.

Kinda' funny though, It also shows that the XR3000 should have the resistor jumped out but that would send 12 volts to a 6 volt coil wouldn't it....... Where do they get these technical writers, and do they make more money then I do?.............**

 

No, there is no adjustment, but I did check it last week when the topic of phasing was brought up and it's right on the money.

Thanks for the replies, fellas. I didn't know if the Crane unit needed 12V to power it up as the Pertronix does. I guess as long as it's getting 8V it should be good to go. I just can't get the idea out of my head that what you put into it is in direct relationship to what you get out of it.

Joe

 

I don't understand how the input voltage could cause the engine to run so far advanced.

Let's think this through: if the Pertronix unit was somehow malfunctioning due to incorrect input voltage, that would mean that it either wouldn't trigger the coil or it would trigger the coil at the wrong time.

If it introduced a delay then you might have a situation where the coil was triggered so late that the rotor arm was not aligned at the correct post on the cap, and the spark would never arrive at the plug, or it would have to first jump a greater gap between rotor and post and you'd end up with a weak spark at the plug. Any bad effect on the Pertronix unit would affect the relationship between where the rotor is and when the coil fires, that's all it can effect.

When you adjust the advance by rotating the distributor you are changing when the spark occurs related to the position of the piston. The whole distributor is rotated, cap and all. If the Pertronix is delaying the spark, then you might have to rotate the distributor body more than would otherwise be the case to get the correct advance, but the engine would still be set using a light at the correct timing. Any screw up in the Pertronix unit would have been adjusted out when you rotated the distributor.

Think what happens when you gap points wrong, it's a similar situation. With the wrong gap an engine either won't idle right or misses at higher revs - because to get the timing right for one means you have the wrong advance for the other. With the wrong points gap you never end up with an engine that runs perfectly, but just at the wrong idle advance.

What we have here is an engine that appears to run very advanced. I still think this suggests that either the vacuum advance isn't working, or the timing marks are wrong.

Kevin

 

I wish I had read this sooner... Maybe I could have backed up "Whisperer"..

I too was having ignition timing problems with the Pertronix... similar to yours.

I had it installed the same way you have it ...with the red wire connected to the + of the coil. After connecting it to a true 12 source I had no problems and the timing was corrected...

"FM".... an electronics term known as F*&%@#! Magic

Tim

 

What you did here, buddy- sounds like to me you answered the very first line you wrote. As for your very last statement, we've already been through that- myself, HUNDREDS OF TIMES. I check and recheck those very same items EVERY TIME I make an adjustment in response to these posts. It becomes fundamental.

I do, in fact, appreciate your post- keep doing what you're doing. That's what I love about this site- it's full of some heavy-duty thinkers- not just a bunch of shade-trees!

Joe

 

OK guys, here ya go.
I went ahead and re-wired the pertronix to the ignition switch as posted above. Cranked the truck, really didnt notice any changes, but I am sure it helped it......
When I checked the timing it was still way off. I decided to pull the distributor and set everything to the number one plug at TDC. Installed the distributor, advanced it just a little bit, cranked the truck and grabbed the timing light and low and behold, it was pretty close to being right. I went ahead and set it at 8* and it runs like a champ. I dont want to stir up some "dodo" here, but I think the "one tooth off" theory was on the money. I want to thank everyone for their suggestions, there are some really smart Ford truck owners on this site. You guys keep up the good work!

 

Joe ... were you refering to my last post ?

I just saw williamwilliam's reply to "whisperer's" post of hooking the red wire to a steady 12v source... he mentioned that he had 12v when the switch was in the off position but didn't mention the voltage reading while it was running... ref 6 posts ago.

I should have mentioned that my response was in ref to williamwilliam's problem not your Crane problem.... however, I did mention Pertronix in my post...

Either way, the input voltage was the source of my timing problems and it seems that it may have been a part of williamwilliam's problem...

Congrats to you williamwilliam... I know how frustrating thoes things can be... especially when you can't figure them out.

I also appreciate your posts, Joe. That, too, is why I love this great site.

Tim

 

Sorry, friend, I was referencing Kevin's post. Your post just came in before mine. But I appreciate your posts, too!

Joe

 

Cool, man...

 

Hey Barry-

I don't know if you can make it out, but in the installation instructions, Crane gives you the basic hook-up first, then on page 13, they give you the ballast resistor notes for a XR700 and then make the statement about bypassing the resistor for best performance. I don't know if you can make it out- I can email you the page in Word Format if you can't.

That is what has me thinking I should try hooking their red wire to a 12V source and leaving the ballast resistor in place for the coil.

I think a call to Crane in the morning is necessary to ask them to clarify their instructions.

What do you think?

Joe

 

Outstanding!

So it was nothing to do with input voltage. I'm quite happy with my own understanding of the "one tooth off" theory to be able to discount that even if it makes others feel better

The good thing is that your truck is set correctly, and running well.

I can't help over-thinking things, since in my job I get paid to think. Wrenching is light relief!

Kevin