electrical problem

[Landy Smurf]

hey i just started my 86 up and reversed and then turned it off to tighten up things. and when i was tightening the battery cables i may have bumped the air cleaner and sparked abit so now it wont start and the lights wont work aka no electrics my first thought was check the fuse but i can only find one fuse and i changed this even though it wasnt blown but still no electrics is there some somewhere else or is it a different issue that is stopping it

[andy_d110]

What is your battery voltage? Start from this and work your way along.

If you have shorted out the battery there is a chance that it has discharged or failed, all depends on how big the spark was, how long it shorted out and the batteries existing condition.

Andy.

[Landy Smurf]

it is a good battery it was just a short spark.the voltage is still good.from what i can see it does not have a fuse box but i thought they should

[andy_d110]

Well if you have good battery voltage, at least 12.6v then you either have an open circuit somewhere or poor connection.

If the aircleaner shorted out on the battery terminal then it woul have bypassed the fuses and they should be ok. Originally they would be on the bulkhead but they may be hiding somewhere else, behind dash maybe? Check your earth connection to the chassis and block.

What is your battery voltage under cranking?

[Landy Smurf]

got it going turns out it was just the negative terminal needed cleaning abit i just thought seeing as it started the first time that this would not have been the problem.anyway i have not started it for about 18 months and it went straight away needs heaps of work but can still drive down the paddock it got a good look from the powerline guys

[wrinklearthur]

Good job, you have got the '86 going again.

With any of the high current connection in the starter motor circuit, they need to be clean and tight.

A bit of corrosion and dirt can cause some disastrous results, for example if the chassis to the bell housing strap comes loose, the current path for the earth to the starter motor is then via the cable outer for the coke into the dash panel.
Much smoke and flame is the result.

W (Watts) is equal to E (Volts) times I (Current); W = E x I, or W = R × I²

Therefore Watts achieved across a dirty terminal can be something like this.

The heat produced by the arcing across a dirty terminal joint of say, .5 ohms resistance and the starter motor drawing 100 Amps, using the above equation, .5 x 100², = 5,000 Watts,

That converts to enough heat generated to blow a battery terminal clean off it's case.
.