Author Topic: In search of the short...fuse block  (Read 4182 times)

seattle_Jerry

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In search of the short...fuse block
« on: September 02, 2008, 22:09:16 »
I'm tracking down the short that is keeping my car from starting.
The wire that connects to the bolt on the side of the distributor has continuity to ground, which kinda defeats the purpose of the plastic isolating washers on the dist.

I removed all of the fuses and checked for continuity on the fuse block.

with the key off:

#1 has no continuity to ground on either the top or bottom of the fuse holder

2 thru 6 on top and bottom

7 thru 12 only on the bottom

with the key on:

No continuity all across the top
on the bottom they all have continuity except 1 and 6


lastly for grins I checked continuity between the wire that comes off the resistor and the fuse block:

1 thru 6 on the top had continuity and all except 1 and 6 had continuity on the bottom of the holders.

What all of that means...I have no idea.

hands_aus

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Re: In search of the short...fuse block
« Reply #1 on: September 03, 2008, 05:12:34 »
the bolt should earth through the closed points.
I suggest you check for earth on the bolt when the points are open.

Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

seattle_Jerry

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Re: In search of the short...fuse block
« Reply #2 on: September 03, 2008, 10:33:53 »
The wire that attaches to the bolt is already earthed before it gets to the points, which is my problem. It didn't matter if the points were open or closed I was still connected to earth.

hands_aus

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Re: In search of the short...fuse block
« Reply #3 on: September 04, 2008, 04:20:34 »
If you haven't already done it, remove all the wires from the bolt and test the bolt to earth.
The problem is if the bolt earths without going through the points the coil does not get the break of the voltage which causes the collapse of the primary magnetic field and hence no secondary output to the spark plugs.
Bob Smith (Brisbane,Australia)
RHD,1967 early 250 SL #114, auto, ps , 717,717
best of the best

seattle_Jerry

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Re: In search of the short...fuse block
« Reply #4 on: September 04, 2008, 09:33:44 »
I disconnected all the wires attached to the bolt and it is not grounded to earth. The wire coming from the coil is though. I've traced it back to the other side of the resistor so far and it is still grounded.