MGB: The old wiring debate

I am in my garage wondering whether or not to rewire the ole girl with an EZ Wiring harness. I used one last year rewiring a truck. It didn't have much trouble, just time. My harness isn't butchered any more than usual I guess, but I am just worried about the integrity of the wire casing and the copper within. My friend had an MGB and sold it because of the electricals, plus all of the horror stories I have read here and elsewhere about the Prince of Darkness. Anyway, I know that all of the terminals should be cleaned and checked before I make a decision. I just want to have an electrically sound vehicle. I know most everyone will steer me toward British wiring or the like when reading this post. I have read man y others, lol. Anyway, maybe the other nubes can get something out of this rehash. So, are there any fellows out there who have used a painless or other generic harness on their stock motor electric?

Thanks, Matt

The obvious problem with going "generic" is illustrated by your question I think.
If you stay stock you have access to innumerable publications (Haynes, Bentley and the like ) and forums such as this to help sort out any problems.
"Generic" requires you to seek out groups or individuals with experience with that particular piece...................not easy.
Not to shoot down some very good non stock re-works, but unless you are experienced in auto electrics in general, and English electrics in particular, you may be well advised to stay with what works. I know Joe Lucas has his detractors, but modern materials and a wealth of experience has been imposed upon his initial shortcomings, to render his less than desirable record almost a thing of the past.
IMHO

The biggest issues with Lucas isn't the wiring. It's corrosion in the connectors and grounds. Address those and you'll find darn near all your electrical gremlins vanish. An unmolested wiring harness is the reason I bought the car I have now, and every electrical issue I've ever had was attributable, and solvable by addressing, corrosion. People want to damn the Prince Of Darkness - I tend to revel in its very simplicity. Or perhaps I'm just nuts...:spinning:B):I3:

I'm with Craig.
I'm also with replacement with OEM.
Try clean up first its a lot cheaper albeit more time consuming. If you are going to tear it out do yourself a favor and get the proper replacement. You'll be glad you did and its a selling point or PLUS to any future owner. IMHO.

When I picked up my '73, almost every electrical circuit or device had issues or problems. I went through it circuit by circuit and device by device. In the end the best thing I did was to replace just about all of the Lucas style wire connectors and put a dab of the electrical "grease" in each connector. Over the years the connectors seem to either become corroded and lose the tension for good connections.

Do not forget (or ignore) the switches. I either disassembled and cleaned or replaced everyone. You gotta love the simplicity that allows these to be opened up and cleaned.

Another issue is the device grounds. It does not take much corrosion (or paint) to induce resistance that will cause a drop in operational voltage. The idea of using the body for the ground circuit was not the best when 30-40 years of age is factored in. I created a sub-harness for the device grounds and made certain that everything had a wired path back to ground. Bright & tight everywhere.

A final issue was the main ground from the battery. The OEM style was to ground the battery to the firewall and use another braided cable to ground the transmission case to the body completing the circuit. As the heaviest draw is when starting, I used a ground cable with a secondary 10 gauge lead and moved the main battery ground cable to the motor and attached the smaller lead to the OEM firewall location thus ensuring the motor had the primary heavy & best ground connection for the starter draw.

All of the above to say that with a little planning and thought the Lucas design is not bad, it is just the lack of maintenance over 40+ years that builds up and causes issues. The only "improvements" that may be required would be if and when certain components are upgraded. If you add high power lights, I would advise adding a relay to the circuit. Also, I did add a fuse for the fuel pump circuit.

Matt, from what I've seen most of the aftermarket wiring kits aren't really compatable with the MG switch gear and such, designed for hot rodders with GM steering columns and such. The one exception would be the kits from Advance Auto Wire http://www.advanceautowire.com/ which are designed from the start to be replacements for British cars. That's the only harness other than a stock replacment that I'd consider. I think Steve's about back to speed and getting his orders filled now after the transfer from Dan Masters to him last year.
That said, I also agree with Craig and Robert, getting the connections clean and in good condition will cure about 99% of most problems on the average LBC. If you're in doubt on the female bullet connections just buy replacements, the rest can be cleaned pretty easily by a quick dip in some CLR and then a rinse. Any loose spade type connectors can either be replaced on the harness or tightened with a pair of pliers for a better connection. Replace the fuse block or solder the connections on it and you should be at a pretty reliable state after that and you'll also have a car that anyone with LBC electrical experience can troubleshoot and repair. One thing I've found from years of having modifed cars, if you modify one then you'd better be ready to work on it yourself, most shops won't touch a modified car as they don't know how it was built and can't get any idea of the hours that might be involved.

Always sage advice Bill
Ramon as well.
The biggest problem and cause to all the "Lucas" jokes can mostly be attributed to the lack of ground. I'd venture to say 90% of the problems are poor ground. The problem is even worse when the ground is positive.

Thanks everyone. Looks like I will be cleaning and goo-ing it all up with dielectric grease. If I have any wire questions I know who to go to!!! Thnaks again guys. I just wanted to make sure that it wouldn't be easier to swap it all out. My reasoning for that would be the learning I would get starting from scratch and recognizing everything. For the most part the wires aren't butchered except for a couple of wires here and there (Couple under the dash and a weird green wire spliced to a large w/b wire from the solenoid). Ta to you all again and cheers!

My '72s harness had a meltdown behind the dash when I brought it home. I replaced it with an OEM and have had no problems so far. The replacement was a piece of cake too.

Matt, you would definitely learn a lot replacing the harness, either stock or aftermarket, but it's not necessary to replace the harness to get a good basic understanding of the MG Midget electrical system. If you're not well versed on automotive electrical systems then I'd suggest taking some time and reading the various sections on the various sub systems such as ignition, alternator, etc on a site such as wikipedia. Most of the time those articles are pretty well written and will give you a basic idea of the sub system, then you can look at the entire schematic for the car and make a bit more sense out of it. I'm not aware of any large format color prints of the Midget wiring harness available on line, but it's very similar to the corresponding year MGB and those are available from Advance Auto Wiring's web site as PDF's. A great resource. http://www.advanceautowire.com/mgb.pdf I find it really helps to have the schematic printed in color, makes tracing the various circuits much easier. After working in electronics for over 40 years I think the easiest way to explain the basics to someone who's just starting out is to compare an electrical circuit to a garden hose. If the flow at the end is low or off then you have a kink in the line somewhere. Same with electricity, if the lamps are dim or don't come on there's a blockage somewhere, either a burned out fuse or lamp, and open switch contact, or a bad connection. Remember, if you don't have a good ground it's like having a cap on the end of the hose, start by makeing sure the ground is good then work your way back. You just need to look at the symptom and then be able to follow that part back through the wiring to the battery or the "faucet" as in the hose reference.

You ARE the man Bill. :beer:

Thanks Bill! I really appreciate your experience and help. I may start "cleaning and grounding" a little tomorrow. Thanks again!

I enjoyed that analogy too! Thanks Bill!

Matt,
When I got my midget it had been unused for 25 yrs. Very few of the electrics worked.Put in a new fuse box, I went through every connection and ground,cleaned it,put dielectric grease on them and every one of them came back to life. Somewhere online I picked up a couple of small wire brushes made to fit into the ends of a lot of the connectors. This worked wonders.
2K miles on the car this season and I only had 1 blinker go out...loose ground that was fixed in 2 minutes.

Pulled the dash out today to start the wire cleaning. So far, the seat indicators or whatever were cut, that's fine I guess. The gauge light dimmer was disconnected (knob doesn't move) and the wires all spliced together, connected to nothing. The green wire that ran from the solenoid is spliced to a red/white wire (gauge illum from column) over near a large connector. Then there is the clump from the radio console (none hooked up, just dangling) Doesn't look too bad since I have my Bently and Haynes. I need to print the big colored one form advance as Bill suggested. I have my dielectric grease ready to go.

Side note: pulled the door panel vinyl off the old masonite and cut new ones from new masonite. Looks pretty good and not lumpy like the old.

Dropped the gas tank and cleaned it. Wondering what to slosh in there to keep it from flashing rust? Sending unit looks ok, dunno if it's operable, may need to test it some how.

OK, I'm done... Had a productive day!:beer:

A couple of tips on cleaning the fuel tank. Be careful as to any caustic types of additives as they can "melt" the plastic screen on the pickup inlet. I took a double handfull of galvanized nuts & lock washers and went through several shake & rinse cycles to get the rust out of my tank.
As to the sending unit any reasonable condition VOM tester should answer any questions concerning if the sender works or not.

Thanks Ramon.

Well I was cleaning some of the connections today. I used CLR, rinsed them, blew air till they were dry, then put the dielectric grease on them. I was working around the turn signal lever and POP. The little tumbler (springed roller) thing that holds pressure on the lever when you switch left or right broke it's surround. I dound it believe it or not and the little roller. I glued it back on, but the pressure was too great and it popped out and shot God knows where. So I will have to get another signal lever unit. I was in a good mood till that happened. lol. I need to get another tip for my weller solder gun at some point as well.