[John Thorne]

Hi everyone, need some help from the brains trust ,

I have sj40 with f10a engine,
when I connect the positive to the battery my dash lights
come on like the ignition is on when the key is in the off position,
When I turn the key and crank the engine there is no spark
At the points or at the plugs.

I have replaced resister, capacitor, coil and points

Please help !!!

[fordem]

I know of no way to get power to the dash lights without it passing through the ignition switch, so I'm guessing the ignition switch may have an issue, and that might also be the reason you have no spark.

If you don't personally have electrical troubleshooting experience, find someone to help you - you're going to need to get a meter and start (a) verifying why you have power when you shouldn't, and (b), that you do have power when & where you should.

On second thoughts - it might be possible for a faulty alternator to "back feed" the ignition system - but you'll still need someone with a meter to verify that for you.

[John Thorne]

I have just ordered one as the next step in I guess the process of elimination.
Is there any info out there on where to start checking/how to’s for fault finding .

Its sound easy to ask but expecting the answer is not!!

Anyone got pics of wiring placement from coil, battery dizzy ect just in case I have misplaced a wire

Any guidance will be appreciated

[fordem]

The real challenge lies in the "learning curve" - some people have difficulty grasping the basic concepts of electricity, and without that, electrical fault finding becomes a frustrating nightmare.

[John Thorne]

fordem wrote:

I know of no way to get power to the dash lights without it passing through the ignition switch, so I'm guessing the ignition switch may have an issue, and that might also be the reason you have no spark.

If you don't personally have electrical troubleshooting experience, find someone to help you - you're going to need to get a meter and start (a) verifying why you have power when you shouldn't, and (b), that you do have power when & where you should.

On second thoughts - it might be possible for a faulty alternator to "back feed" the ignition system - but you'll still need someone with a meter to verify that for you.

I unplugged the Alternator cables to see if this would isolate the issue
But and it still remains ☹️

[MrRocky]

Try and run a couple of earth cables to engine block and firewall.
Also test coil and ignition with test light remembering most items on sierras are negatively switched so some will have power to them all of the time.