SwEm Technical Bulletin Number 3  01/03

Attention All P1800 Owners:

Replace your fuseblocks!  (Please note underlining and Bolding)!

The original poor Lucas design, combined with years of corrosion, will lead to continuously deteriorating electrical connections.  Initially the poor connections may only cause nuisance problems (rightfully attributed to "Lucas, the Prince of Darkness"), and the heat generated due to resistance heating will be able to be safely dissipated, but at some point (determined by the conditions in which the vehicle is stored and driven), the heat can cause real damage including an electrical fire!

In my opinion, replacing your Fuseblocks is not an option!  It is required, especially when performing an Alternator upgrade, to safely handle increased currents available from the Alternator!   


Suggested reading:  Gas-Tight-Joint, Part II

Shortly after I wrote this tech article, this posting appeared on the 1800 Forum of Brickboard.com:

Fusebox fire! [1800]
posted by someone claiming to be Dave on Fri, Jan 10th 2003 at 11:42 PM

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. circuit 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 flammable wire jacket! Anyone have any additional comments?

Link to entire "Fusebox Fire!" thread.

See also:  I2R Heating

SwEm upgraded 1800 fuseblocks are available.  Link to SwEm Kits page.

I hope "Dave" takes my advice before he looses the car to a fire.  Ron


I recently ran across this...it is not of a P1800, but I expect this thermoscan is very representative of the condition of "Dave's" Fuseblock if he had looked at it in the IR spectrum!

Thermal scan of an equipment fuse panel showing typical and perfectly normal, slight heating of fuses themselves, but also result of very  extraordinary and excessive I2R heat generation at one of the fuse connections.  This could be due to looseness (loss of fuse-socket spring preload or screw terminal looseness, or similar), contamination, or corrosion (and this is the order of likelihood of causes on an electrical panel, inside and protected from the weather, where it is only subjected to condensation-causing temperature excursions), as found in the  later, 1800Es or ESs, where it was moved into the cozy interior...only a closer inspection can determine exactly which might be the precise cause. 

In a vehicle where the Fuseblocks were located in the engine compartment...like the earlier cars, like 444, 544, 122, 1800, the order of likelihood of causes immediately changes to move contamination and corrosion to the top of the list!