I just had a problem with my fuse box. The fuse was not blowing but it was getting so hot that it was starting to smolder the fabric wire jacket right above it. It was the acc. circut so the wipers and fan went of. I have not had a chance to look at it in the light. In the morning I'll give the thing a good cleaning and do something about the flamable wire jacket! Anyone have any additional comments?
Thanks
Dave

Dave;

I hope the damage is limited, but DO NOT RUN CAR FURTHER BEFORE READING THIS AND: http://www.intelab.com/swem/gastight_II.htm

Heat is caused by "resistance heating" - Ohms law states that you'll make Watts (heat) when conducting current through a conductor. If the resistance is low, no problem, but if that conductor and its connections have high resistance (in the case of that awful Lucas fusebox, typically caused by the poor design, corrosion, and exacerbated by the inadequite force from the whimpy little fuse clip), the heating WILL become worse and worse and eventually lead to your symtoms and beyond.

Replace your Fusebox before you torch the car! ...and not with an equally awful new one, but with a SwEm upgraded one.

Cheers

My guess is that your problem goes beyond a fuse. I would first check the fuse and see if it is the right size for that circuit--it's probably too large and was placed there to mask another problem. If that is the case, then you need to isolate which accessory is creating the problem.

Rolfe--'71E

Perhaps I am masking another problem in my using of 35A fuses instead of 30A (which my manual recomends). But I have been using 35A fuses for four years without any problems so I doubt suddenly that suddenly the fuse would heat up. I'm guessing that the problem is the poor condition of the fusebox (it looks in sorry shape and is dirty).
Cheers
Dave

Dave;

First, I wonder what manual "recommends" 30A fuses. Both the owners and multiple shop manuals I checked do call for 35A.

Second, installing a higher rated fuse would DECREASE any heating, since a fuse also works by resistance heating of the internal element, and a fuse of a higher rating actually has LESS internal resistance (heavier element) to allow more current to pass until its limit is reached and it burns open.

Yes, you have a poor connection, but it doesn't have anything to do with the fuse itself! Your hot fuse is caused by resitance heating of the fuse connections and fusebox contacts...nodowdaboudit!

Cheers

I understand the fuse bit. I was responding to a suggestion that the fuse was the problem. I have an old british manual that says 30 amp fuses are used. I used them until I got sick of replacing them. I wire brushed my Lucus fusebox until it gleamed and reshaped the clips and the problem was fixed. I do plan on getting another however. Thanks for the tip!
Cheers
Dave.

Another thing you can do is get rid of those HORRIBLE European ceramic fuses. They corrode and break and are generally a pain to remove/install. Buss makes replacements which have sealed glass tubes and plated metal ends. The only difference between them and standard (pre blade) auto fuses is that these have conical (pointed) ends.You won't find these at Pep Boys, but if you go to an auto parts store specializing in foreighn car parts you should be able to find them. Or, like me, you can contact Buss directly.I've used these for years on Volvos, but it seems most people don't realize this easy and cheap fix is available.

Dave B;

Dave did not state the year of his 1800, but from "fabric wire jacket" you know it to be an early 1800...and early P1800s do not use conical end eurofuses. Also, and there's really nothing inherently wrong with those fuses which just a modest amount of maintenance can keep working just dandy FOREVER...and by maintenance* I only mean keeping the ends clean and free of corrosion and applying a dab of zinc-paste. Ask any 122 owners and about a million original Volkswagen bug owners too! With time, if ignored, contact problems develop. If kept clean (and better yet with a gas tight joint to the contact), you can just about forget about them unless one truly opens as a result of an overcurrent.

I outright disagree that eurofuses are difficult to remove or install unless you're wearing mittens.

The Glass bodied replacements dO NOT address OR FIX the problem of galvanic corrosion due to the contact of dissimilar metals (so even the gold plated ones available will not prevent this, only slow it down), the ONLY long-term solution is a gas tight joint, made by using anti-corrosive paste.

The best (and "easy and cheap" solution) is to clean and treat the fuse ends.

* ...and don't get me wrong...I don't spend every weekend communing with my cars (nor do I want to...I would by a British car if I wanted to do work on it for an hour for every two road hours)...I have a life, and so I basically square them away, and then make them work for me, while I do my best to ignore them...that's why I developed long-term fixes and improvements...these allow me to do the other things I want to and keep me from necessarily having to fiddlefart around after something fails.

Cheers

Ron, Baring removing the fuse box rivets on my '64 1800 I've cleaned the oxidisation up as much as I think possible and bought a tube of Zinc anti-corrosive paste that I plan to use on the spades and fuse ends when I re-install in the car. One thing I noticed, particularly on the single fuse box is the fittings are a bit loose in the bakelite frame. Would it make sense to infill the back of the frame with non-conductive epoxy to give all of the pressed tight fittings a bit more rigidity?

Graham;

I guess there's no question if you used the site search feature...this is certainly a thread from the archive...

Refer to the pictures of the construction of the FBs (Ref: https://www.sw-em.com/gastight_II.htm ) one can see because of the two piece construction of each terminal, that there is literally "strictly incidental force of a couple of bent over tabs occurring as a byproduct of holding the two separate terminals onto the plastic base" ...once these tabs are loose, you might be able to demount the FB to gain access to the rear, and rebend them to secure the terminal into the base better. Thankfully, those tabs are not in the current carrying path...

I don't know about filling the back with epoxy, as there are holes which would allow the epoxy to run out and away. I use non-leveling RTV for filling the back on the ones I rework...it is not susceptible to running out of the bottom and away...

Don't forget also, that the FB with single fuse in the early 1800s, the fuse should be changed to 10A rated 3AG type. See: https://www.sw-em.com/tech_bulletin_4.htm

Cheers