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MG MGB GT V8 Factory Originals Technical - Fuse Box?

Considering re-wiring the V8 conversion and wondered if anybody care to comment on the best type of fuse box to fit; either blade type or traditional glass fuse type?

Walt, look into Painless Co. they have fuse boxes and kits, perhaps the best on the market.

Bill Guzman

Thanks Bill, but read the question again... which is the best type?

He answered the question in a round-about way. The painless kits are only available in the blade type if my memory serves me correctly. Painless is THE leader in rod and custom wiring, they do thier research and know what they are doing. If they choose blade type, that tells me what is the best.

From a replacement standpoint, the blades are nicer, no glass to break, and all modern cars use only the blade units. They are color coded by amp rating, so no needing to squint reading the ends, just grab the right color and go..
Larry Embrey

It's one of those things, how do you want it to look and what are you going to do with it.
I wanted to maintain the Lucas look but add a little more options. I added an extra Lucas/MGB fuse box beside the original. Twice the fuses.

Blade fuses are better, but so is a new Lexus.
Kelly Combes

In my experience, the problem with the OE Lucas box is that the spade lugs get gunked up and cause a significant voltage drop. In my one single move of unoriginality, I soldered two $4 Pep Boys blade-style boxes (one to replace the fuse box itself and one to use for the in-line fuses) and I am so, so, so much happier (the in-line fuses were painfully unreliable, and they control important circuits like your windshield wipers; the regular fusebox was reliable, but I was getting a major voltage drop across it). It is very easy to do; if you take a bit of time and get some matching wire, you can do an ultra-clean installation and it looks thoroughly appropriate.

OR you can submit to the rip-off of ALL time and pay $60 or so for the replacement fuse box from Ian Pender and his partner and use that ... it has the wires already on it. (I have nothing against Mr. Pender, I just think this is an unbelievable markup; sorta seems to be contrary to the spirit of how most of us operate.)


Another option you might want to consider is making your own wiring harness, as per the plans in the May 2001 issue of the British V8 newsletter.
Cost will be comparable to the Painless system, but it will use the correct color codes for your MG, and will have 8 fuses and 6 relays - more than adequate for your V8 conversion. By using relays for all the heavy current switching, your MGB factory switches will wear out mechanically before they fail electrically. If you need more than 8 fuses, just stick in another 4-gang fuse box and go.

I agree with what everyone has said about Painless - they put out a supurb product, but I believe the system shown in the newsletter is more suited for our cars.

I have upgraded the plans, and I will be publishing them on the British V8 website soon. This wiring system uses blade type fuses. There are some very neat blade type fuses out now, with an LED that glows when the fuse is blown. They run about $0.75 each at Autozone, but they are worth it in my opinion.

At the risk of being flamed for advertising, I am putting together do-it-yourself kits for this system, except I'm using larger gauge and better grade wire than listed in the plans (still the correct color codes). Contact me off list if you are interested.

As far as blade vs glass fuses, I really don't see any real advantage of one over the other. The contacts can corrode with either type, causing voltage drops. Depending on which fuse block you buy, the blade type may use spade lug connectors also, the same as the fuse box you now have. Whichever you choose, do a good job on the connectors, keep the block inside the car if possible, and keep them clean. If you can, buy the type block that lets you crimp and/or solder wires to the fuse connections, rather than the male/female spade connectors. This is one of the real advantages of the Painless system - the wires are crimped at the factory, using very expensive, automated crimping tools for a superior connection. Depending, that is, on which one you buy. They also sell systems that allow you terminate your wiring on the block yourself, using screw connections. This type is a lot easier to install, but the other is better.

Come to the British V8 convention in Tennessee in May - I'll be giving a seminar/tech session on replacement wiring systems for V8 conversions.
Dan Masters

Centex GV21 was my choic after talking to the local street rod shop specializing in wiring & A/C installations. I am on my third car using that product. I did look at Painless, American Autowire, Ron Francis & a few others before making my choice.

Big thing in changing to any new wiring system is to get modern blade fuses, improved connections at the fuse panel that are better insulated than the Lucas push on connectors. That was state of the art in the 30's, never updated until production ceased in 1980. Shurly there there were improvements in the field of automotive elecronics somewhere in that time frame, & into today's world. I see no reason to perpetuate this outmoded techology unless you are doing a concours restoration, which elinimates almost all V8 owners.
Jim Stuart

I am wondering if there is a car already out there, Ford Chev etc which would lend itself to a fuse box conversion for out cars?

Try This is the setup i'm using.Small and compact,unlike painless wich is the size of a motor cycle battery!
DTR Ross

A good blade-type is no better than a good original. But if you want to fuse additional circuits there is (in the UK at least) a 6-way blade-type that is the same overall size and has the same fixing centres as the original. Doesn't include two spares, though ...
Paul Hunt

Dan's option is absolutely fantastic. I shudder to think how much work that was. Much less impressive than Dan's design, but I was able to make up a sub-panel & harness, with relays & thick, well-connected wires, to use on some of the high-current circuits, and I soldered in blade-style fuse boxes as per the above, and for the past two years anyway electrical problems have simply been a thing of the past.

This thread was discussed between 02/11/2002 and 04/11/2002

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