canbaufo

I'm a complete noob when it comes to wiring and I am replacing my bad MSD6BTM with an MSD6AL (I can tune out ignition timing so I don't need the BTM anymore).

First problem is neither of the leads will reach the battery or terminal. I think I'll just ground the black lead by putting it on a supercharger bracket bolt (perfect fit and unpainted surface). Is that an ok place to ground it? I do have a ground strap going from the engine to the chassis.

The red lead is only inches short of reaching the terminal post (non battery). It can reach the positive of the actual battery but won't fit. I noticed someone extended, spliced, soldered and shrink wrapped the positive lead on the old MSD so it could reach and they did a very good job.

My connectors were mostly wrong sex on the new MSD (connections to coil being the orange and black ...connections to trigger and 12 volt source being the red and white). Wrong as in female where they needed to be male and vica-versa (some but not all). Previous installer had the same problem with the old MSD so I borrowed the adaptor wires with butt connectors from it, they're in great shape.

So long story short I have two wires to cut and splice. The black wire that goes to the negative of the coil (it is yellow) is the first one. I didn't have anything adaptor-wise handy for it so I just cut the male black end I needed from the old MSD and did a solid "Western Union Style Splice" on it and used some electrical tape (no soldering yet). I then put some small cable ties on it to really hold it together well and honestly ....I think that's all it needs, is that stupid? That wire's not going to see much load or stress of anykind other than heat. This car get's 1-2K miles per year. I put more electrical tape on top of the cable ties so they won't cut things.

The other one's a little more serious. The positive lead of the MSD. Like I said it will not reach, so I cut the loop end off of it and stripped about an inch of insulation off. I have already done the same to some extension wire that was already there from the old install that's connected to the positive terminal (non battery up on the wheel well). The last person did it right with soldering and heat shrink. Can I at least temporarily get away with a Western Union Splice and electrical tape (tightened with small cable ties)? ..bad idea? Or ...maybe just soldering and electrical tape or the splice and heat shrink?

I've never soldered before or used heat shrink and kind of don't want to bother with buying the stuff. Also I hate for my first time to be on a car, especially a serious thing like a positive lead. Should I just splice and tape for now....then drive it to my mechanic friend to have him solder/shrink it right? ..or am I making too big a deal out of it (could a really good splice and tape be fine as long as I'm careful, and add the extra touch of the cable ties keeping it tight)?

Sorry so much detail, again ....is grounding the MSD's negative lead on the engine (on supercharger bracket bolt) ok as long as it's solid (it is)?

I've obviously never done anything serious with wiring before, but I can follow the instructions pretty well and feel confident there ...just not sure what protocol really is on necessity of soldering and/or shrinking. My gut tells me splicing and taping is fine on the one little black wire going to the coil, but for the bigger positive lead I really should solder at least in the bitter end. Correct?

Injuneer

Get the correct MSD harness, and you won't have to splice anything with regard to the coil connectors. The MSD box wires connect to one end of the harness, and the other end connects to the stock coil connectors.

http://www.msdignition.com/product.a...&terms=harness

The radiator support header is a good ground. Many factory wires are grounded to the screws on the top/back of the support. Extending the red 12V wire is simple. I used a high quality crimp connector, made sure the piece of wire used as an extension was a size larger than the wire on the MSD, and used heat shrink to cover the crimp connector.

grabbem88

don't sweat the solder stuff...since i mess with alot of r/c stuff (radio control cars) i solder on a regular basis..

here is a little help for ya....got a butane lighter?..if not a basic bic lighter works..

get a basic assortment of shrink tubes from autozone..a few bucks...

you can get the shrink tube connector splices as well reall easy or solder the wire then slide shrink tube over it and shrink it..

when soldering...take bare wire and drop some solder on wire..one drop is all you need..then take other bare wire and have it ready..heat wire with solder on it till it gets
melted soft..don't touch solder just the wire needs heated..then take other wire and apply it on melted solder wire..take solder away and hold wires together for a few seconds and it's mended solid..then slide shrink tube over bare wires then take lighter and shrink it..and you have what you need..

about grounds i'd try to get it on block,but your ground will be fine..

power supply should never be directly on battery termonal..so any key on 12v power supply will do the job..nothing less nothing more..

hope that helps

grabbem88

the harness is the best option..less than 20 bucks and no hack job or cutting...and if something ever happens to msd box you can just unplug it and plug it back to stock and not be stranded or pay for a tow truck

canbaufo

Too late for me to do that since it wasn't used first time around. Take a look at these instructions for the #8876:

http://www.msdignition.com/uploadedF...structions.pdf

The previous installer spliced and butted the wires coming from my coil connectors....in other words, the factory harness is no longer intact. There is one yellow wire coming from the bottom of one of the coil connectors and two red wires coming from the top of both of the connectors. Right now the old MSD is bypassed and those wires are connected to other yellow and red wires. I am assuming I would install the MSD6AL the same way the MSD6BTM was before it was bypassed. This would mean I splice the orange wire from the MSD into two wires with a one-into-two connector. Then connect those to the red wires coming from the coil connectors. Then I'll take the black wire of the MSD and connect it to the yellow wire that goes to the bottom of one of the coil connectors.

Then the white wire from the MSD goes to the yellow factory wire that the yellow wire from the coil connector used to go in.

Finally the red wire from the MSD goes into a one-into-two connector and they connect to the red factory wires the coil wires used to go in.

Arrrrghhh, this is confusing (especially for someone to read without seeing it) but after a lot of studying I felt quite sure this is the right way to do it....do I seem on track? Since that nice #8876 harness wasn't used before I'm pretty much screwed out of being able to use it now. I haven't figured out where the actual BTM box for me to remove is yet. It concerns me a little that the BTM instructions call for the use of a yellow wire. One yellow wire and two red wires are all I could find the coil hooked up to (in bypass mode) so the yellow must in effect be acting as the white wire.

The reason the old ignition was bypassed was to toubleshoot a warm re-start problem I had. Once it was bypassed the problem went away and stayed away....hence it is being replaced.

I have already cut and spliced the black wire from the new MSD. At this point I think a harness is a waste unfortunately. Would have been nice ...would have made it so much easier to bypass too.

I really don't have a clue how to solder or shrink. Can some other heat source other than a heat gun work (like a hot work light...ha ha, never mind, I see "grabbem88" answered my question while I type this post...lol I had thought of a lighter ....cool). I noticed the radiator support header already in use as a ground, but the instructions say to ground it to the engine. Is the supercharger bracket ok? Thanks guys.

grabbem88

just be sure to not put direct flame on shrink tube...it won't hurt anything..just be black from the flame..hell iv'e used glue guns solder guns and my wifes hair dyrers<her high dollar crap will melt skin..lol!

you could use the really good male/female plug connectors..they are water proof insulated and can unplug if needed..

your bracket will be fine..it's bolted to heads which are bolted to block right?..i used my intake before..and i have used the radiator support bracket..all did not effect charging nor spark if you are wondering..

canbaufo

Thanks for the info. Sometimes you just need a little assurance when you're working on these things alone for the first time. I don't think I'm going to sweat it too much. I think I'll just do a good smooth Western Union splice for the positive lead and shrink wrap it ...call it a day (no solder). That shrink wrap is tough stuff...I'll just overlap it onto the insulation a good bit so it has a lot to bite onto. It will be under my radiator cover anyway, not like it's going to get poked around at or tugged on much.

Only thing worrying me at this point is the lack of wires compared to diagrams (like I said, my dual-connector coil's connectors have one red wire on top/positive of each but only one yellow is on one bottom/negative). So there's only a total of three wires when directions always call for four, maybe it's where I'm OBDI instead of OBDII and most directions are for OBDII.

What's killing me is how painfully simple this would be if I was starting from scratch with an #8876 harness, not to mention more efficient and easier to bypass. I can still bypass my setup in an emergency, it's just a lot more involved. I wonder where the yellow wire from my BTM box (that I'm removing) connects ....probably inline with the yellow wire from the dual connectors. Argghh, I hate uncertainty. I may just install but not wire and drive it to my mechanic friend's place. I just wanted to have it done and feel good about doing it myself.

Thanks for the tips, I will keep this updated when I do something more.

Kevin Blown 95 TA

Just my opinion, but you would probably make more power with the BTM set up correctly than with taking out timing at <=100KPA since you're not really even into boost yet, unless you're doing some fancy 2 bar programming.

grabbem88

he would if it wasn't bad..and he is trying to use something that he has that is better than stock ignition..sorta..the stock ignition isn't that weak compared to other v8 bretheren cars of that era

canbaufo

Hahaha I see why I've confused myself so much. When looking at these directions for dual-connector coil and timing control they are for timing CONTROL, not BTM. I didn't realize that until I zoomed in to see the PDF better:

http://www.msdignition.com/uploadedF...structions.pdf

So I had myself looking for a timing control box with a yellow wire attached that didn't exist lol. So this is much easier to remove than I thought. There is a connector just for the BTM and I pulled it out through the firewall grommet.

Kevin Blown, I understand the reasoning but I didn't want to spend another $170 to replace my BTM so I stuck with the 6AL. Actually, varying by cam/head design, compression, etc ....you might make more power by tuning straight from the LT1 Edit like I'm doing. Because you may be able to get away with more timing than stock at 80-90 KPA (I see what you mean about the =100 part though). I don't do any extra timing over stock at high KPA's though, would rather play it safe and make a little less power to be honest. Below say 60-80 KPA I use a little more than stock in some areas to make up for the cam and reduced compression (I tune mine open loop for smoother cruising too).

Also it's safer in one respect using tuning instead of the BTM, what if the BTM fails? I'd rather just have the 100+ KPA areas reduced in the actual programming so I know it's gone for sure. The only caveat to this is I no longer have my BTM to compensate for those unusually dry-cold / dry-hot days or for times it's been run hard for long periods ...but that's all rare and I tune conservatively anyway.

In spite of that, this little 355 with it's little Powerdyne making about 6+xx PSI made 446 RWHP on a 93* day and 445 RWTQ (mobile dyno, hence the heat in the summer when the pull was made). It makes 400 RWTQ all the way down at 2,400 RPM! In spite of the correction factor that is included in these numbers I would guess it would do ~20 hp better on a cooler day since it's non-intercooled (effect of HP loss is greater than correction factor with supercharging).

My props to 89TTA94LT1 for those numbers.

canbaufo

It's installed and works great! My girlfriend came over and taught me how to solder lol (she uses it for stained glass art).

No chances taken: Western Union splice, solder, heat shrink, electrical tape, cable ties gently applied on top, cable ties covered up with electrical tape. lol I think that will do it. The only two wires I had to fool with was extending the positive lead (and I used one size up for the battery as Injuneer suggested) .....along with soldering the spliced black cable that goes to the negative on the coil.

Everything seems a tad more crisp ...quicker start up and throttle response. The old issue with not re-starting when warmed up is gone

Feels good to do it yourself the right way. Thanks for all the help you all!

grabbem88

glad to chip in to help,and glad you got it figured out!