Fuse blues ....

[fixerupper]

A question for wiser folk than me ....The 10 amp fuse for the side lights and dash lights on my Mazda 2500D 4x4 pick-up keeps blowing...all the another lights work fine ...I replace the fuse and the lights come on for a second then pop...so tomorrow I'm gonna investigate ...any clues were I should start...
could it be a bad earth on the side lights ? frayed wire behind the dash board ? ...I'd like to fix it me self if I can or at least eliminate the obvious things first before I enter in to the dark and murky world of Cretan motor electricians ....

 

[johnik]

I would start by disconecting the bulb holders to see if it is one of them,apart from that,has the dash been out, radio fitted etc ?.
i have an analouge ammeter and a bodged fuse so i can check how much each circuit is taking without poping hundreds of fuses.

 

[Pete.]

Stick a nail in the fuse holder and look for the smoke

Worked for a mate of mine. We were at a landspped racing event and his bike kept popping a fuse. In desperation we did this and found that the loom was very slightly pinched behind a fairing screw.

 

[fixerupper]

Thanks, so the first place to start is the side light bulb holders... If I stuff a multi meter in the fuse box will the lights work ,and will it read 12volts ?

 

[8ob]

Going by similar problems on our trucks I would look at the towbar urlektriks, quite often poorly fitted and seem to get pulled about a lot .The jap stuff rarely gives problems.

Bob

 

[fixerupper]

That tow bar electric tip is worth looking at first ... when I bought this truck 12 years ago the socket was smashed , I don't have a trailer so I taped up the cables and cable tied them out off the way then took off the broken socket ...I'd forgotten that

 

[dobbslc]

Check any extra charging points or radio / amp connections. I was also going to say look at any tow bar electrucks!

 

[500e]

Have seen bulbs that have short circuits & blow fuses, cheap to remove all bulbs inc No plate & see if fuse still blows

 

[fixerupper]

Have seen bulbs that have short circuits & blow fuses, cheap to remove all bulbs inc No plate & see if fuse still blows

Sound advice ... first thing in the morning , I'm out there thanks all ....

 

[rtbcomp]

I had a similar problem, someone had had the tail light cluster out and trapped a wire so it shorted to the body.

 

[angellonewolf]

Stick a nail in the fuse holder and look for the smoke

Worked for a mate of mine. We were at a landspped racing event and his bike kept popping a fuse. In desperation we did this and found that the loom was very slightly pinched behind a fairing screw.

other halfs father done this after paying for someone to find the fault they could not

he went back put a nail in it and looked for smoke found it in 3 mins wire shorting on the body shell

not saying to do this by the way but worked for him

 

[CKJDJK]

Make up a test light with a bulb couple of wires on. Plug the wire into the fuse box in place of the fuse. Careful you do not short across the two terminals. The bulb will glow bright due to the short circuit fault. It will also restrict the current making it safer. Then check all bulb holders and remove the bulbs one at a time. You can get an internal short inside a bulb as already said by 500e. The test bulb will dim when the short is found. If capless bulbs used check the little wires coming out of the glass are not shorting the socket. If that does not find the fault then you need to check all the wiring systematically. If it has a towbar check inside the lighting socket and the cables to it.

 

[fixerupper]

Well ...I pulled everything to bits , went to the local garage and spent almost an hour rummaging about in drawers and boxes ..for the correct number plate light bulbs , stop tail bulbs.. with the old guy who runs it ....checked all the connections , cleaned the dust and muck out of the bulb holders , re taped up the loose cables that were for tow hich...I found nothing that I would think could cause the problem ...So I put it all back together , decided I should take it to the Electrilogos ( Auto electrician ). in the morning , so feeling a bit miffed I stuck a fuse in the fuse box switched on the the lights and ... It did'nt blow ...so it's fixed but I don't know why ...

 

[angellonewolf]

^^^^^^ as long as it dont come back

 

[fixerupper]

Well I think It will....devil of a job trying to track down a intermittent fault like this ....

 

[angellonewolf]

nail

 

[Wallace]

Good call on the trailer socket, check for moisture and verdigris on the cables. Particularly on the car loom where the Scotchlok's* are likely to be.

* Scotchlok, a horrid w**** piece of c*** sold by a company that makes mainly good products. (Apart from Scotchloks)

 

[angellonewolf]

^^^^^^ yes there carp but do a job i would not use it where it inportant but my towbar is fitted with them it was 2nd hand and the bloke was scraping the car so cut the wiring loom so i had a very easy time fitting the scotch lock where on there i opened them and reused them and all been fine (prob up till i have posted this) i did want to do the proper job but time and the things where there and having never fitted one before i wanted to make sure all is fine before soldering

its a job on the list but as its working at the mo it can stay

 

[eSCHEn]

I stuck a fuse in the fuse box switched on the the lights and ... It did'nt blow ...so it's fixed but I don't know why ...

It's obvious isn't it? Just a simple case of a handed fuse. Must have been in the wrong way to begin with.

They make them in the same factory as the quantum usb connectors. You know, the ones which don't fit so you turn it over and it still doesn't. But because you observed the event you changed its outcome so now the original wrong way is right.