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Discussion Starter · #1 ·
I thought this would be an easy task until I found that funky old coil is different from every other car I have ever seen. No positive voltage 12V terminal. I guess I can wire in the Pertronix with the existing coil using the IPD diode wires, but I was hoping to also swap in the Bosch blue coil that so many people have recommended. Looks like a pain. I guess I can fab a blanking plate to close off the hole in the firewall left by the old coil, but maybe with a small hole and rubber grommet for the wire between the ignition switch and the coil. That means cutting the armored cable, which is sort of a point of no return as far as keeping it bone stock. I guess I could get some kind of universal aftermarket ignition switch (unless a proper Volvo one for a later version already exists) and keep the old coil with its integral cable and switch intact if one would ever want to reinstall it later. Curious as to what others have done, looking for suggestions. Thanks in advance!
 

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SM;

Electronic Ign modules can be installed without having to cut anything (like the Armored Cable!). Ign power can be taken from Fuseblock (Ign power input, not fused side, unless you want a blown fuse to park you!) Diode cable is necessary only if you still use Ign Key into Pos 4 to energize Starter (which is not recommended)...it is NOT necessary when combining elec Ign with a mo. Start Switch (always a good preventative against broken Ign Key).

If your Ign Coil is working without issues, there's no good reason to change it...but if you have your heart set on installing that Bosch Blue, you must gain access to the otherwise inaccessible Ign + node, so cutting Armored Cable at one of the two ends is the only option.

This is covered this in detail here: http://www.sw-em.com/123Ignition_in_a_Volvo_with_Armored_Cable.htm

Further suggested reading: http://www.sw-em.com/Volvo Ignition...e Volvo Ignition system and the Armored Cable

Good Hunting!
 

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Discussion Starter · #3 ·
Thanks Ron, I have been reading your posts elsewhere and they are really helpful. Since I posted earlier I have read that there is a voltage drop with the Pertronix module that results in a weaker spark. So a hotter coil seems warranted, and I already have the new Bosch blue coil. I think I will begin by removing the present coil/cable/ignition switch assembly intact (if possible) and then deciding whether to chop it to keep the old switch or just put in a new aftermarket ignition switch. Is it truly necessary to cut the armored cable in any case? If so I will just keep the old switch.
 

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I have successfully drilled a ~1" hole in the base of the stock coil using a hole saw. This allows access to the connection, which is dead-center under the bottom cover. You can cut and splice it there.

Another possibility is to get a coil mounting sleeve, there is a guy from Greece on eBay who sells them. They fit in the hole in the firewall, hold the coil, and look kind of nice. This allows removing the stock coil and ignition switch as an unmolested unit. You can then install an aftermarket ignition switch, or even use one cut off a "parts" coil, all the while preserving your original.

Is your coil a 2-bolt or 3-bolt flange? The guy makes both.
 

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Discussion Starter · #5 ·
It has a two bolt flange. I think I will start by trying to remove the assembly intact, and failing that, hacking the cable with a dremel tool. I do not see any point in keeping the old coil with an electronic ignition, knowing that the spark will be weaker. I sure do not want to start cutting holes in the coil casing and continuing to use it. Unless it has some kind of double wall construction there at the base it seems like a scary idea. Ignition coils are sealed for a reason. Even cutting a hole only to connect the wire and leaving the old one there as a dead hole plug and then mounting a new coil on the other side seems pretty goofy. Won't do it, wouldn't be prudent...
 

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SM;

"voltage drop with the Pertronix module that results in a weaker spark"...a transistor in the module is used as a switch, and it essentially takes the place of points, so I have to question that statement at the very least, because I see no way to technically explain it...what voltage drop?...and where? and how does it result in weaker spark...I don't buy it without a valid explanation! (for the electronically qualified out there: a 0.2v Vce Sat. of that transistor switch is minuscule and will have negligible affect!!), ...besides, there are many OE Ign including with original Coils which have had elec ign modules added, and they work fine with no such complaints...

Cheers
 

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Discussion Starter · #7 ·
I am sure your knowledge of circuitry vastly surpasses mine, which gets shaky just beyond V = iR. Other have reported a measured voltage drop with Pertronix modules with the engine running. Am I a victim of 'fake news' about getting a weaker spark? Perhaps a weaker spark might not matter as long as a minimum arcing voltage is obtained, as long as there is enough spark energy to effectively ignite the fuel/air mixture. Some advocate upping the voltage to compensate using an adjustable voltage regulator.
https://forums.swedespeed.com/showt...nic-ignition&highlight=pertronix+voltage+drop
 

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It has a two bolt flange. I think I will start by trying to remove the assembly intact, and failing that, hacking the cable with a dremel tool. I do not see any point in keeping the old coil with an electronic ignition, knowing that the spark will be weaker. I sure do not want to start cutting holes in the coil casing and continuing to use it. Unless it has some kind of double wall construction there at the base it seems like a scary idea. Ignition coils are sealed for a reason. Even cutting a hole only to connect the wire and leaving the old one there as a dead hole plug and then mounting a new coil on the other side seems pretty goofy. Won't do it, wouldn't be prudent...
Ok, and to be clear I am not trying to convince you of anything, just giving information.

The coil base is single-wall, and it is not very hard to cut the hole I described.

BUT! The armored cable is not going to yield to a mere dremel. There are two spiral-wound layers of very hard spring steel, and they are wound in different directions. You cannot simply cut into it and unwrap a layer. Honestly, don't underestimate that armoring.

The assembly, however, will come out intact fairly easily. There are three electric connections behind the ignition switch, two screws holding the switch to the dashboard, and two bolts holding the coil to the firewall. Bob's your uncle.
 

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SM;

The point is not to compare levels of expertise, but to hopefully put our heads and experience together to understand and get good service from our cars and modifications...thanks for that informative link...I have read and digested the info, also learning new things there, and have to admit, a 1V switching voltage loss could indeed result in a weaker spark, but luckily, this will only be a significant issue under a low Battery condition...it looks like less under normal situation...

Regarding an Adjustable VReg...I just don't think these are necessary if Charging System and Battery and connections are operating normally...typically tickling the VReg up in voltage is a band-aid to compensate for decreased voltage elsewhere occurring because of a V Drop on a poor ground, or poor series connection on Ch Sys output, etc to name just two...I advocate locating and eliminating voltage drops...at corroded crimps or loose terminals is relatively simple (and that's why I'm such an advocate of ACZP), but if on a wire, it might need paralleling with another to increase cross section of conductor and decrease resistance...

Edit; I tried to resurrect that linked thread, but system wont let me post to it...again that 1V seems high and I wouldn't expect it from a switching transistor...

...also...good info from tmtalpey!

Cheers
 

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Discussion Starter · #10 ·
Thanks guys. Really appreciate the sage guidance. I think I will pull the whole unit. It looks like one needs to remove the lock cylinder first, and from what I have read there is some pin that engages it with the outer assembly, and this pin can only be depressed with the key in the 'on' position. Looks like a bit of a contortionist's act to carry out this task. I will attempt it when the numerous clients and family members allow me!
 

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Pressing the pin is actually rather simple, but only if you know where it is. You can do it with your finger, from the driver's seat, even.

But since you plan to remove the whole switch, you're going to need to remove three nuts on the electrical posts, which means you'll be under there upside-down anyway. You'll be able to do it then.
 

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Discussion Starter · #12 ·
I was hoping there might be enough slack in the wiring to first remove the switch from the dash and pull it out into direct view, then disconnect the wires. I guess I need to get in there and find out for real.
 

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I was hoping there might be enough slack in the wiring to first remove the switch from the dash and pull it out into direct view, then disconnect the wires. I guess I need to get in there and find out for real.
Yes you can flex the armored cable (it's stiff, and room is tight) but first you have to remove the cylinder and the trim ring. Then remove the two philips screws holding the ignition switch to the dash. Then it's just a matter of 'butching' the ignition switch back from the dash, avoiding lighter and other wires and down under the dash lip. I believe that there is enough slack in the wires that connect to the switch to allow you to do this before disconnecting them form the ignition switch, but I might be wrong.

Of course you've first already disconnected the battery....

You might find that a tiny socket (7mm?) makes it a lot easier to loosen those pesky nuts on the ignition switch.
 
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