Honda-SOHC

SOHC.co.uk Forums => CB750 => Topic started by: Waggles on July 30, 2012, 07:35:21 AM

Title: Blown fuse: Most likely culprit?
Post by: Waggles on July 30, 2012, 07:35:21 AM

My F1 stopped dead on the way to work this morning, traced it to a blown 15A fuse, so I replaced it with a nail ( kidding  ;) ) no I fitted the spare and all seems fine, no blown bulbs, headlight was on, was only at low revs.

Obviously could have been the fuse itself ( it is original 1976! ) and I will be chacking for loose connections, but for those with loads of experience what have you found is the most likely culprit?

Title: Re: Blown fuse: Most likely culprit?
Post by: SteveD CB500K0 on July 30, 2012, 09:20:28 AM

Old fuses = trouble.

Number 1 culprit!

Title: Re: Blown fuse: Most likely culprit?
Post by: mick on July 30, 2012, 10:39:32 AM

Hi waggles a short usually blows a fuse , i had a fuse blow on me because 2 wires had rubbed on a metal part in the headlight bucket, cheers Mick.

Title: Re: Blown fuse: Most likely culprit?
Post by: Waggles on July 30, 2012, 11:07:24 AM

Cheers guys.

Will check in the headlamp shell, things are tight in there on an F1, but I think it should be OK as I had all that apart during the rebuild. Think Steve may be right, looking at the blown fuse although not bad I can detect tiny rust spots on one terminal, could be enough to raise resistance and hence heat.

Have obviously ordered new fuses, will clean up the fuse box and replace them all

Title: Re: Blown fuse: Most likely culprit?
Post by: Waggles on July 31, 2012, 07:22:20 AM

Just an update, cleaned all contacts and fuses last night. First observation was that the blown fuse was the only one exhibiting a little corrosion, observation 2 was there was signs of heat at one end of the fuse holder.

Reckon that, added to the fact its been OK since ( he said touching his head and getting a splinter ) points to the dodgy fuse, if a short blew it I would expect it to go so quickly there would be no sign of heat? ( other than the blackening of the inside of the fuse of course )

Title: Re: Blown fuse: Most likely culprit?
Post by: Spitfire on July 31, 2012, 09:32:49 AM

I had a problem on my F1 with fuses, it turned out to be corroded connections on the back of the fuse unit, cleaned up , re soldered and everything was good.

Cheers

Den

Title: Re: Blown fuse: Most likely culprit?
Post by: Waggles on August 02, 2012, 07:20:38 AM

Cheers Den, could be that, must admit I assumed that the rear connections were soldered and therefore had to be OK so have never checked them, will have a look at the weekend

Title: Re: Blown fuse: Most likely culprit?
Post by: Spitfire on August 02, 2012, 09:16:29 AM

They were soldered originally but had corroded, so I was getting an intermittent contact.

Cheers

Den