At 10:36 PM 11/17/05, Mike Lupynec wrote:
"I am running low on my original Lucas fuse inventory. Are the Moss 50 and 35 amp fuses slow blow 25/50 and 17/35?"

I hesitated to post this with Faulty Parts, as I cannot verify if the parts are functionally faulty or not. I only know that they are not properly labeled, so they cannot be positively identified by outward appearance.

Recent distribution of fuses, Moss Motors, Ltd, part numbers 146-700 (35 Amp) and 146-800 (50 Amp) have been plain glass fuses with no "Lucas" or "Slow Blow" label. I cannot verify functionality without sample testing a few out of every order batch, and it would be a royal PITA for every individual customer to do that. I contacted Moss on this issue. They say they are assured by their supplier that these are the proper slow blow fuses. My translation is, Moss does not test the things on receipt, so no one can know for sure. If these should ever happen to be delivered as standard type fuses (not slow blow type), any short in the circuits of your car could burn up the wiring harness without blowing the fuse.

Since the Moss fuses are not labeled as slow blow, you cannot tell them apart from standard fuses. If you trust the Moss fuses to actually be slow blow type, then you should put them in a separate package clearly labeled with the Moss part number and write "Slow Blow" an the package.

I will not trust an unlabeled plain glass fuse to be the slow blow type unless it comes with a certification sheet to that effect (which Moss does not supply). The plain glass unlabeled fuses I recently received from Moss have gone in the trash bin. I do not have time in my life to independently purchase large quantities of plain glass fuses and sample test the batch to verify if they are really slow blow type.

I figure it's safer to use a standard 20 amp fuse than to take a chance on speculation that a plain glass fuse labeled "35A" might be a 17/35 slow blow fuse. Standard equipment running on the green wires in the MGA should not blow a 20 amp fuse.

For the other fuse in the dedicated horn circuit, that circuit may draw quite a high current surge for a short period of time. The service manual says when service testing the horn (as in long blow while adjusting the points for max volume) you should short across the fuse to prevent it from blowing. This implies that the dual horn setup might draw 25 amps or more. I would recommend trying a standard 25 amp fuse first. If it blows out at 25 amps, maybe try a 30 amp fuse, but absolutely nothing higher. Wiring should really be 10 AWG to carry 30 amps continuously, and there is no 10 AWG wiring in the MGA.

If anyone knows of a source for properly labeled slow blow fuses, please let me know.