Did a compression test on my stroked Olds 215, not good. #4 cylinder at 50 lbs.

[Gswest236]

Great, I ordered the wire harness and heat shrink solder connectors.

[Gswest236]

I unwrapped the wires back enough that I'm not seeing a splice of the red and white wires. I'm not sure this control box is the same as what we're seeing on MSD's site. I haven't seen a Multispark 6AL anywhere. But at this point I don't see a black/orange wire or a Black/Violet wire coming from the box.
But there are Red and White wires. I guess I have to remove the box.

[Gswest236]

This is my model box on Ebay. The wires look like mine. Red and white wires can be seen. I'm wondering if the wire colors changed after they stopped making this ignition box.

[mgb260]

Black/orange+ to (violet) and black/violet- to (green) from distributor. At the plug it changes from the MSD box to green and violet. In that picture the plug with the green and purple wires above the box plug into your distributor plug.

[Gswest236]

When I type in model #6420 (which is on the box) on MSD's site nothing comes up. The only thing close is this model which isn't the same but it is Multiple Spark Discharge. The part # Wayne Ridley has for the box is 803033. MSD tech said that isn't in their system. So, Holley bought MSD and maybe some older stuff wasn't kept in the system.

[mgb260]

Either it was hooked up wrong or the wiring was changed between the distributor and box. The diagram I sent on the last page /post #811 shows where all the other wires go. The one you ordered on Ebay has the plug with purple and green wires that plugs into the distributor plug in the top of the picture.

[Gswest236]

I took the box off the fire wall thinking I could unplug the wiring harness. Theres a plug with the green and violet wires but the rest of the wires are hard wired inside the box, no plug. The pic is the diagram on the back of the box. The green and violet wires I marked their location and they were water temp sensor from the intake manifold and another sensor on the manifold. So, At this point I'm looking at  A new Digital MSD6AL box #6425 for $350. The condition of the wiring is so nasty and the wires that are color coded  are going to the wrong place in some cases and have been spliced in multiple areas. I'm thinking starting fresh is the way to go. What I don't understand is it was working the way is is wired.

[Gswest236]

This is what I'm considering.

[mgb260]

I personally know of 3 that failed in the last two years. The older ones like yours were far more reliable.  Your diagram shows green and purple to magnetic pickup(distributor) coming out of the bottom. If you have to, can you take the cover off and wire as I suggest?. The green and violet wires to the sensors have nothing to do with the MSD box.

[Gswest236]

I appreciate the input! Looking at the wiring after unraveling all the tape; it is too sketchy for me. The way its run thru the firewall it looks like they did it the way the AC hoses were done, some kind of filler as opposed to a rubber grommet. I can't unplug the wires as they are hard wired. I can't turn or move the box much because the way the wire bundle is run/attached to the fire wall. It's a mess with a bunch of spliced in random colored wires. (some of which aren't ignition related) And they're all absolutely soaked with oil. So, for my mental wellbeing, I'm better off starting over with new. If I could pull the box and wires out, put it on a table and figure out what each wire is, I'd attempt that. But, I can't so with my zero electrical know how, a new box with instructions and new wiring harness is very appealing.

[mgb260]

Scott, It would be easy on the bench. You cut off the wires about a foot away from the box. You would cut the plug off the new Ebay harness and match the colored wires by size and use the solderseal connectors. Sounds like the whole car needs to be rewired! We are going to use a Speedway 12 circuit wire harness in Jon's car. The diagram on the back is really the same as the one I sent, only the distributor plug is separate. None of those wires need to go through the firewall. You just need to find a wire that is hot with the key on. I'll send an image of the 4 pin HEI on another engine similar to how we mounted Jon's. You could mount it on the firewall or fender too.  I think it is a better option and much less expensive.

[mgb260]

4 pin HEI:

[mgb260]

Here's our harness:

https://www.speedwaymotors.com/12-Circuit-Mini-Fuse-Universal-Hot-Rod-Wiring-Harness-Kit,2352.html

[Gswest236]

OK, I appreciate the help. I think if I pull the box and wires out, I'll then be able to see what's goin on. I think they wrapped all the wires going into the engine bay together; that's what makes it confusing to me. There's not a bunch of ignition wires to deal with. So at that point I'll figure out which direction to go. Thanks!

[Gswest236]

Didn't get the ignition box out today, lost power for a while. But at least I got a package.

[mgb260]

Cool! There is red, black and white heatshrink to cover the splices and make them almost invisible.

https://www.ebay.com/itm/374963966998?_skw=white+heat+shrink&epid=8037953461&itmmeta=01KRQ4MY83ZRAB8ZF1E3QDY68A&hash=item574d981416:g:z8QAAOSwclJlGop9&itmprp=enc%3AAQALAAAA8GfYFPkwiKCW4ZNSs2u11xDgJnbalSN9yLrRGLm6nst1qQHHARPQAymQiJ%2F2f9B0WMOgKd7tl14%2BPDoYlPALya4DIbvoeZ18rVyvrB4FO0mNf1E5jZLbc9Sds3EaSwQ0S%2B58TZmFjzZxmWPxmU2gH%2BbsFlqjl8j%2Bg7gO80FSE1anNc5RsP%2BrFM5wP07abkahokNwfZHcyyCl--VrhrhqcFIckcgyrpTvUBtx%2BvkMk3Rm%2F2PLE9O4FkQTQpdqwiQl4BOnajb5eGgfCSXYCWRGdFhIePAQJhjqXvjBnM9u8QHkkQ83g0lOGw%2B9R%2BBv%2BfBFsw%3D%3D%7Ctkp%3ABk9SR6Lk0-TFZw

[Gswest236]

Nice! Another package coming.

[BlownMGB-V8]

I've used some of those and they are OK but really the jury is still out. Overall I still mostly use the heat shrinkable crimp ones with the hot glue inside. They are faster and seem just as reliable. These take a lot of heat to work right, the wires can't have any oxide on them, and stray ends can puncture the insulation when it's hot. Overall probably the best way to use them is to smooth and pre-tin the ends of the wires before inserting them into the connector.

Jim

[Moderator]

I guess I'm probably a carmudgeon and that I'm hopelessly old school, but at points in my career I've been responsible for spec'ing electronic automotive components and also for designing wire harnesses for heavy duty commercial trucks.

I'm extremely skeptical of MSD, and particularly skeptical of their boxes. It seems like every racing paddock I've ever been in has contained some poor sod fiddling with a broken MSD6AL.  And didn't Pete Mantell have to replace an MSD6AL at a BritishV8 meet one year? My recollection is that he got a replacement from an auto parts store, that it was dead on arrival, and that he had to procure yet another one to get going. So I really think you're far better off without one. Keep things simple. And generally, in any case at all where you can choose OEM parts over blingy aftermarket crap - I would do so.

When wiring things up, I try to avoid making inline splices. I prefer the serviceability of connectors and specifically I strongly recommend using Delphi/Packard Metri-Pack connectors wherever possible. I use the proper crimping tool, and if I've got any doubt I back the crimp up with solder (careful not to use too much or to overheat the insulation.) 

Where I must use inline splices: I've never trusted a crimp that's made overtop of an insulator or a solder joint that's made with a heat gun. Those things might work, but I don't trust them. Instead, I use a splice clip and I certainly back it up with solder (applied with an iron). Then I cover the splice with dual-wall (i.e. adhesive lined) heat shrink tubing. In cases where more than one lead enters one end of the heat shrink tube, I have a little trick. I slice a thin sliver of glue-gun adhesive and use it to supplement. Companies that make OEM harnesses buy adhesive ready-made to be used like this... but I've never seen it in a catalog or online. Upon inspection, you should be able to see the adhesive has sqeezed out slightly around the full circumference of every lead.

[Gswest236]

Thanks guys! I'm looking at some of those Delphi connectors; not cheap, but probably worth it. I did get    the box out and am waiting for the replacement harness. They must not have had the harness when they installed this box, so they "custom" wired it up. My aim is to get the correct wires
going from the box to the engine bay. And get rid of all the red and white wires. Apparently that's what they had and thats what they used, everywhere.

[BlownMGB-V8]

I'm partial to the Deutsch connectors myself but they have gotten pretty expensive. I'm not completely happy with their length of pin engagement but their connector bodies are the best I've seen and the locking mechanism is superior. A decent assortment now costs somewhere around $200 but the bodies and pins are available separately from Del City and others.

I'm with Curtis regarding MSD. Got one in the spares cabinet I should have thrown away long ago, it just quit for no good reason and they seem to have a failure rate that is way too high. Their claim to fame, the multi-spark never gave any advantage that I could tell. Just another fancy box with sub standard internals. OEM parts are much more reliable and do the job as well or better. I suspect there is one or two common components inside the box that regularly fail but with no schematic available good luck finding it. I found the Ford EDIS to be way better and now use the GM COP. No way I'd waste any more time on MSD under any circumstances.

Curtis' approach to wire termination shows his industry experience but most of us aren't out to build multi-million mile rigs so we aren't as likely to dedicate quite as much time to it. We probably should but it does take a lot of dedication. If you are doing a new re-wire with cross linked wire like AAW sells and going exclusively to gas sealed connectors then yes, it probably makes sense. Otherwise maybe not quite so much and slightly lesser methods can apply. A crimped and soldered joint is always going to be the most reliable and with proper preparation need not take any longer than a simple insulated crimp, bearing in mind that solder can cause embrittlement in copper wires though I can't say I've seen that myself. Fortunately we have several good options and you can pick what you think will work best for you. Unfortunately MGBs were made before gas sealed electrical systems were ever a thing so it's darned near impossible to convert everything over. (And yes wipers and key switch I'm thinking of you.)

Jim

[Gswest236]

Thanks Jim, All the electrical stuff worked well before and I'll be happy if that's still the case after the motor's back in. The ignition box and new distributor are getting rewired mainly to make it easier to diagnose electrical or ignition issues. I had no electrical issues before; the MSD system worked well. It is a little scary to hear the bad reviews of MSD systems here. I'm hoping Jim N. is right and the older MSD boxes are more reliable!