9 replies to this topic

[CharlesK]

hi guys, i'm new to the forum
A couple of months ago i bought an austin mini red hot from 1988.
i have just run into an issue, i noticed my indicators and horn werent working so i checked the fuse and it had burned out. not only that but the previous owner soldered copper around the outside of the fuse to bridge it because the fuse had already burned out on him. i went to the shop and the guy told me the fuze that was in it was a 30 amp fuze. i thought i'd get a box of 30 amp fuzes and see what happnes. i put the fuze in, turned the ignition and the fuze glowed red hot and melted. i noticed some bad wiring from an old radio that used to be in there so i took it all out but to no avail. i then proceeded to take out the dashboard unit and disconnect all the steering collumn swithches and buttons. leaving only the ingition connected. still the same problem. if i disconnect the green cable from the fuze leaving only white-fuze-purple it does'nt short.

I have tried finding a wiring diagram but no luck so far. does anyone know what the green cable connects to or why it could be shorting

here's a pic of the fuse and cables.
 IMG_20120726_194001.jpg   63.66K   8 downloads

[tiger99]

You really do need a manual, either Rover if you can get one, or at least Haynes, and they both contain a variety of wiring diagrams. Likely none will match your model exactly, as there were so many variants, but the wiring colours are common to all.

Green feeds indicators, carburettor solenoid if fitted (hopefully not, as I don't know where its switch is located, maybe a thermal switch on engine?), dim dip unit, reversing lights, stop lamps and heated rear window.

I would automatically remove the dim dip unit and link its brown/blue and brown/red wires. That is one less problem later on, and can be safely and legally eliminated for ever, while making the dipped headlights more reliable.

Check the state of the green wire at the reversing light switch. This is of course under the car, near the exhaust, which makes it prime suspect. Stop lamp circuit may be chafing near the pedal (nasty contortions in footwell, or a mirror may help). Check at heater rear window switch, and at indicator (not hazard) flasher.

It is just possible that your car has something else on the green circuit too.

[hawthorne]

Correct me if I'm wrong but the fuse should be 35 amps for the top fuse, I was having the same problems recently as the alternator chopped through my wiring, turned out the wire was just shorting on the body and just needed insulating after soldering the wires back together, sorted that out but now my hazards don't work, minis ay? If I were you I'd just go back to basics and check all the wires are insulated. You never know could just be something simple.

[CharlesK]

ok, thanks. i'l check again tomorow. it's getting too dark now. i'l check in again and tell you guys where i'm at tomorow

[CharlesK]

had a good look again today, could'nt find anything out of the ordinary. turned the car on and the fuze didn't blow. rode it for a bit and it held up. my indicators don't work but the high/low beam works fine. i rode it without the instrument panel so that may be why. i still have no idea what was wrong though. hawthorne said the top fuze is 35 amps, can someone confirm this? i have a 30 amp at the moment.

[tiger99]

Yes it is 35 amps. The fact that you have a 30 amp fuse makes me wonder whether it is the correct grade of fuse that you are using. Car fuses of the old Lucas type are rated by instant-blow current, and a 35A fuse might only be able to carry about 12 to 15A continuously, whereas normal fuses are rated by continuous current. If your 30A fuse is continuously rated, it is far too high, and a fire hazard, as some of the wiring will ignite with less current than that. I have never seen Lucas type fuses rated at 30A, which is what made me wonder.

[CharlesK]

i went to the car parts shop to see if he had the lucas type fuses. he had never heard of them so i bought some 15 amp fuses instead. problem is, the fuze still keeps shorting. i disconnected the brake button this time but no luck. i also tried poking the wire on the bottom of the car for the reverse light because i can't lift the car enough to get under it.

i've tried looking for a open wire somewhere but all the green wire seems to run in the original wiring harness. where else could the green wire be susceptible to damage i just can't seem to find the problem.

[jimnali]

The reversing light switch sounds like a prime suspect for this problem.

Underneath the front carpet you will find two wires leading in towards the base of the gear lever. these have bullet connectors joining to the leads for the rev light switch. Disconnect the connectors (making sure that ends are insulated) replace the fuse and test it.

Chances are the leads to the switch have shorted against the exhaust and are causing the problem. You will need to replace the swkitch to fix tthe problem but you will need to get the car high enough to safely work underneath it. This means a solid set of ramps or axle stands. If you are not familiar with this you might be better to leave this job to a garage.

You do need to get 35amp fuses - 15amps will not cope with the current on this circuit. Try ebay for suitable fuses.

[CharlesK]

The reversing light switch sounds like a prime suspect for this problem.

Underneath the front carpet you will find two wires leading in towards the base of the gear lever. these have bullet connectors joining to the leads for the rev light switch. Disconnect the connectors (making sure that ends are insulated) replace the fuse and test it.

Chances are the leads to the switch have shorted against the exhaust and are causing the problem. You will need to replace the swkitch to fix tthe problem but you will need to get the car high enough to safely work underneath it. This means a solid set of ramps or axle stands. If you are not familiar with this you might be better to leave this job to a garage.

You do need to get 35amp fuses - 15amps will not cope with the current on this circuit. Try ebay for suitable fuses.

thanks, getting underneath the car is not a viable option within the next couple of days. i'm glad to hear there's a connector under the carpet to disconnect it, atleast i'l be able to drive normaly again. EDIT: hopefully

Edited by CharlesK, 28 July 2012 - 10:06 PM.

[CharlesK]

hi, i checked under the carpet today and there was a bad fix done with ductape. i traced the cable back and almost all of the insulation had melted off. pretty scary considering it ran along the carpet. i took the wire off and everything worked flawlessly. thanks for the help everyone. i posted some pics to show what the wire looked like and how badly it was fixed previously.

Attached Files

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