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something's blowing a fuse - NOW WITH PICS
oval TOFU - March 1st, 2006 at 03:25 PM

..and I don't know what it is. I've recently removed my engine in my '55 bug to replace a front gearbox mount with a urethane bush. The grounding strap was bolted back onto the stud that comes out of the chassis, though it was a bit of a stretch.

I've replaced all the other wiring to the engine and I haven't made any mods to the wiring. I've checked that no bare terminals are touching any tinware etc. I didn't remove the starter motor or touch any of the wiring to it when I removed the engine. When I turn the key to the 'acc' position, the main fuse (16A) blows after about 3 seconds. On the multimeter, the current reads off the scale. I've never blown a fuse until now. A 55 bug has only 4 fuses.

(a) Could the possibility of a poor ground from the gearbox-to-chassis strap cause the fuse to blow (in my mind, higly unlikely)?

(b) Does anyone have any suggestions of where or how to start the process of elimination to figuring out what is sorting out?

(c) The wire from the dizzy's condensor goes to the negative terminal on the coil right? (The other two wires on the other terminal go to the auto choke and to the fuse box)


Please help! I'm getting desperate:cry

[ Edited on 3-3-06 by oval TOFU ]


Bizarre - March 1st, 2006 at 04:05 PM

Ground strap will have nothing to do with it

Yes the condenser goes to the -ve. The +ve is power, choke and solenoid cut off.

All's i can suggest is disconnect as many "power" wires as you can see. If it blows with them disconnected then it HAS to be caught on a bit of tin somewhere


Do you have a reversing light??

they are switched power


oval TOFU - March 1st, 2006 at 04:20 PM

I don't have a reversing light (hooked up anyways..) I'll see what happens when i pull all the 'power' wires off and let ya know..

Mean while, don't be shy with other suggestions people!


geodon - March 1st, 2006 at 04:28 PM

I'd start looking at how u wired the voltage regulator back. Is there an earth wire that u mistakenly put on a hot terminal?
Diagnosis? It may be crude rude & vulgar but I disconnect wires, switch on, then touch/flick them where they are meant to go one at a time & watch for big-time sparks indicating a heavy current in that particular circuit.


Grey 57 - March 1st, 2006 at 04:36 PM

Chris you sure you havent trapped a wire between something metal?? What about the oil light wire?? You havent got this one and the positive from the ignition mixed up.
Thats all I can think of?? If you had the negative wire grounded (from the distrubutor) the only thing that would happen is the the motor wouldnt start. Not blow the fuse.


blutopless2 - March 1st, 2006 at 05:34 PM

ah they joys of electrical faults. it definitely sounds like you have a partial shorted wire somewhere, and most likely in the engine bay if that's where you have been fiddling.
can only suggest as above... disconnect things from the fuse that blows and reconnect one at a time to figure out what is blowing the fuse.
good luck


Purple Martin - March 3rd, 2006 at 07:42 AM

It's not a poor gearbox-to-chassis ground strap, that would mean less current and no fuses blowing.

If the reversing light isn't hooked up, what has happened to the loose end of the wire that normally goes to the reversing light? Could the end of that wire be touching part of the body?

Immediately after the fuse blows, do any wires feel warm to the touch?


oval TOFU - March 3rd, 2006 at 10:40 AM

Quote:
Originally posted by Purple Martin
It's not a poor gearbox-to-chassis ground strap, that would mean less current and no fuses blowing.

That's what I thought too..

Quote:

If the reversing light isn't hooked up, what has happened to the loose end of the wire that normally goes to the reversing light? Could the end of that wire be touching part of the body?

I have no reverse light wiring at all.

Quote:

Immediately after the fuse blows, do any wires feel warm to the touch?

Immediately after the fuse blows, I can pull it out of the fuse holder without burning my fingers. The fues itself didnt feel too warm. I couldn't tell if the wires felt abnormally warm due to the fine fine weather in Melbourne lately..

I've discovered that the current of the lead coming from the battery/starter (B+) connecting to the regulator goes off the chart. But that's literally wired straight from the battery, so is that normal?

I trialed a 25A fuse in place of the 16A: it's doesn't blow straight away, but after 10 seconds or so, you can smell it cooking.. It's got just under 18A going through it. so why would a 25A fuse start to smoke? The wires going to the multimeter were warm after that..

[ Edited on 3-3-06 by oval TOFU ]


oval TOFU - March 3rd, 2006 at 11:04 AM

4 fuses, I'll label them I, II, III, IV in this instance. (from left to right) Yup, I isn't even being used here.....:o

1) black wire: loops from IV to III (as the current flows)
2) it's pretty obvious that I and IV are bridged. No current with the ignition turned off.
3) from IV to the flasher can
4) from IV to the lower speedo light
5) goes up the A pillar to somewhere
6) goes to the horn
7) superfluous wire leading to grey curcuit joiner thing(but not grounded either)

I hope this helps a bit..

Failing fault finding this, whats an estimate of the cost of rewiring the front of the car with stock colour coded wiring?

Who knows that proper fuse values that I should be using - including the additional two for the headlights (positioned nearer to the fuel tank)?

I hate this shit.



[ Edited on 3-3-06 by oval TOFU ]


oval TOFU - March 3rd, 2006 at 11:20 AM

this is to prove that I've got the rear wiring correct:

8) ignition wire (to fuse box or whereever)
9) to dizzy
10) to auto choke and cut off soilnoid

And i'm 100% sure that the coil's terminals are the correct way around. In my case, (+) is on the left side.



[ Edited on 3-3-06 by oval TOFU ]

[ Edited on 3-3-06 by oval TOFU ]


killakornkobb - March 3rd, 2006 at 03:32 PM

fucking cars:jesus


Old Dubber - March 3rd, 2006 at 05:53 PM

How have you connected the generator wires????


oval TOFU - March 3rd, 2006 at 06:43 PM

Quote:
Originally posted by Old Dubber
How have you connected the generator wires????


Correctly I'm pretty sure..
refer to the pics above, sorry I forgot to attach them the first time around..

[ Edited on 3-3-06 by oval TOFU ]


hellbugged - March 3rd, 2006 at 09:09 PM

Quote:
Originally posted by oval TOFU


(c) The wire from the dizzy's condensor goes to the negative terminal on the coil right? (The other two wires on the other terminal go to the auto choke and to the fuse box)


Please help! I'm getting desperate:cry

[ Edited on 3-3-06 by oval TOFU ]


in your picture, you have marked the wire to the key and condensor as if both are on the same side? yep dizzy should be on ----- side, wire to key on the +

i'm thinking that unless your running a rev counter the only wire on the ---- side would be the dizzy?

any one else?, its been a long time since i have run a standard system

[ Edited on 3-3-06 by dumone ]


Bizarre - March 4th, 2006 at 09:29 PM

Dumone - you are right

In the picture you have the dizzy (condenser) going to the same as another wire.

this will be your problem

The condenser goes to the -ve

All other +ve wires go to the other side

Bet a beer this is your problem


oval TOFU - March 4th, 2006 at 11:51 PM

Quote:
Originally posted by Bizarre


Bet a beer this is your problem


You're on. I'll try it tomorrow. I hope you're right!


Grey 57 - March 5th, 2006 at 08:08 AM

Yep thats your prob Chris. 8 & 9 should no t be on the same terminal on the coil. This is a dead short. Swap 9 & 10 and you should be on your way.
Good luck. Call me if you have any more trouble mate. 0412 500 588


oval TOFU - March 5th, 2006 at 09:53 AM

att: Dumone and Bizarre. I owe you beers.

It's all good now! :bounce:bounce:bounce I musta read the wiring diagrams incorrectly - majorly incorrectly.

Can anyone tell me the fuse values for the respective I,II,III,IV fuses as well, the two headlight fuses?

Ta

Thanks for ya offer too Dean :)


*did* - March 5th, 2006 at 10:22 AM

nice one!


hellbugged - March 5th, 2006 at 10:49 AM

:beer cheers.


killakornkobb - March 5th, 2006 at 04:18 PM

wicked! so has she settled now?? nice height in the ass?


oval TOFU - March 5th, 2006 at 11:39 PM

Quote:
Originally posted by killakornkobb
wicked! so has she settled now?? nice height in the ass?


Leave my donkey out of this.

I haven't driven it yet, I still have to set the timing and bleed the rear brakes. Though I could just go up and down the driveway and use the handbrake........

yeh, I think I'll do that!


Just waiting on tie rod ends, then I can start to take the front apart too... Like the late Big Kev used to say, "I'm excited!"


oval TOFU - March 5th, 2006 at 11:40 PM

Dumone and Bizarre - come to the Jambo to collect ya beers!