Continuously Blowing The Same Fuse

[ECR033]

Hoping someone with some auto-electrical knowledge can help me out

Over the last few weeks, my car ('97 R33 GTS25t) has developed some sort of minor electrical gremlin that's been causing it to continuously blow the same fuse over and over again (well, I changed it 3 times then gave up). It's a 10a (amp?) fuse and I've tried the follow the wires from the fuse, looking for something odd, not connected or shorting out etc, but everything seems fine (although I admit I'm an absolute novice when it comes to these things and didn't get very far with it, so in all liklihood I've probably missed the problem).

Basically my interior clock and my stereo do not work when the fuse is out and additionally, my climate control unit doesn't switch on automatically on start up (i.e revert to last setting when car was switched off) but I can still turn it on and operate as normal. Everything else seems to be working fine.

Unfortunately the wiring diagram is in Japanese, so I've done a search from English diagrams, but basically the only description I could get was "electrics 10a" which wasn't of much help. The fuse in question is in the dash fuse box, left column, 7th fuse from bottom (i.e first fuse in 2nd section).

Can anyone suggest anything I can do to rectify the problem? Or, alternatively, can anyone recommend a good auto-electrician in the Parramatta/Hills area (Sydney)?

Thanks guys

[PHATR32]

left colum?

which one is that?

[topper]

From my experience (over 25 years) as an Auto Elec, over 90% of short circuits, ie blowing fuses, is caused by

people doing something, eg changing stereo, screwing a self tapper unknowingly thru wiring loom, connecting something incorrectly etc, the way wiring looms are run in general cause very few problems..

So the first thing I would be doing is thinking what has been done to the vehicle in the past few weeks, and start from there. I am afraid I don't have a wiring diagram to help you but hopfully this may trigger something in your memory and send you looking in the right direction.

Cheers,

Neil

[ECR033]

PHATR32,

Going off your wiring diagram, it's fuse 17 (although the layout looks slightly different to my fuse box - not sure if there's a difference between series 1 and 2 R33's?)

Neil,

Thanks for the advice. Basically, I haven't made any mods recently, other than replacing a clutch and O2 sensor a few weeks before these problems started (all of which probably doesn't have anything to do with my problem?). My stereo and EBC have been in the car for over 18months and I put a Nismo dash in the car a fair while ago...other than those things, I can't really think of anything else that I've changed that may affect the wiring, so i'm a bit lost

[PHATR32]

oooo shit sorry man, that diagram is off a r32 gtr.

didnt even look to see what you had!!

ill try to find one for the r33

[Fangz]

sounds like my sort of field,

try this:

remove the fuse and put a multimeter (dc amp mode) probe on each side of the fuse holder and see how many amps are flowing through the circuit, if over 10A obvesley is gonna blow

remove the fuse and put a multimeter (continues mode) on a ground somewhere under the dash and probe each side of the fuse holder if it beeps theres a dead short in the accessory line somwhere

to try fix this do u have a aftermarket headunit?

or anything fitted anything electronic in the last week or so?

its ether a short, overload, faulty component, or bodgy install

im in north syd if u want me to check it out 4 ya (send pm)

[RANDY]

Good call on the continuity mode on the multimeter!

Have you tried unplugging the power to your HU and testing whether it blows?

I've heard a few stories of the 12v line for the A/C / clock / HU blowing like this. I don't think we've ever worked out what it was.

[mad082]

i have a fusebox wiring diagram (got a translated manual with my car) and will scan it to post up. its too cold to walk out to the car now, but if it is switching off the stereo then its pretty obvious which it is. at a guess i'd say that it could be that a wire has come out of a plug, or has be squash between the HU and the mounting brackets and has worn through due to vibrations and is shorting out.

[ECR033]

Thanks for the input

Just to clarify, I do have an aftermarket head unit, but it's been in the car for the best part of 2 years now without any problems. I've also got a electronic boost controller, but that's also been in the car for at least 18 months. I'm guessing that if it's got something to do with either of the above, it's probably because something has come loose or some wiring has worn through somewhere, otherwise it might be something else.

I'll pull the headunit out over the weekend and check that everything looks ok and see if it still blows the fuse when it's disconnected.

I'm a bit of a novice when it comes to electrical stuff, but I'll also see if I can borrow a multimeter over the weekend and give your suggestions a go Fangz (thanks for your offer to help - I might drop you a PM if I have any problems).

If all else fails, i've got the contact details for a good workshop which also does auto electricial work - i've already planned to book the car in to get some mechanical work done (just waiting a few weeks for some parts to arrive), so I'll probably get them to try and sort the auto electrical stuff out for me as well if I can't figure it out.

[topper]

sounds like my sort of field,

try this:

remove the fuse and put a multimeter (dc amp mode) probe on each side of the fuse holder and see how many amps are flowing through the circuit, if over 10A obvesley is gonna blow

remove the fuse and put a multimeter (continues mode) on a ground somewhere under the dash and probe each side of the fuse holder if it beeps theres a dead short in the accessory line somwhere

to try fix this do u have a aftermarket headunit?

or anything fitted anything electronic in the last week or so?

its ether a short, overload, faulty component, or bodgy install

im in north syd if u want me to check it out 4 ya (send pm)

Not to be rude but the trouble with your first 2 paragraphs is this,

From what ECR033 has said it appears that this problem is intermittent( even if it isnt we still dont learn anything from this), so when testing the current draw with a multimeter if the short is not on at the time of testing, the reading he gets will tell him nothing, if the short is there it tells us only what we already know, but not where the problem lays. We already know at some time the current draw is enough to blow the fuse, the difficult part is what is the cause? It may be a case of disconnect one at a time, all the accessories that feed off that fuse and drive the car for a while, a process of ellimination, not great but it may lead to a solution.

Edited July 13, 2006 by topper

[ECR033]

I've just re-read my first post and apologise if it's a little confusing.

Just to explain, my car originally blew the fuse in question a few weeks back. I then replaced the fuse and drove around for half a day until it blew again. I replaced the fuse another 2 times, although on both occassions the fuse only lasted approximately 5 or so minutes before blowing the fuse again...at which point, I gave up and asked for help

Not sure if I would classify this as an intermittent problem, as it seems pretty constant to me, but I'm no expert, so disregard my opinion in coming to your own conclusions

I'm going to disconnect the head unit over the weekend to see if it's causing the problem. Failing that, I'll also disconnect both the clock and climate control to try and ascertain whether either of those accessories are responsible for the problem. If I still can't figure it out (quite likely!), then I'll book the car in to get my mechanic/auto electrician contact to have a look at it - my parts arrived today, so hopefully this issue will be sorted one way or another next week.

I'll post up the outcome either way...

[sinistaGTR]

will be a loose or dodgy wire somewhere most likely, for it to be tempremental.....