HELP!!! My SHO wont start

[New to the SHO]

Its had trouble starting every once in a while, but last sunday night it just gave up. I pulled out the starter and it wasnt worn down, and I got it checked an auto parts store to make sure it was giving power. Then I replaced the cillanoide... It still wouldnt start. I know its not the battery connection because my interrior lights are on and i can turn it over to the third stage in the ignition.... every interrior panal instrument works. When I was rope towing it home and when I was trouble shooting the random stuff would happen like the lights wouldnt work or the cd player would turn on and off, my door locks flickered locked and unlocked like 50 times too, that makes me think its a short, but where do I start??? Am I best off just taking it to a shop?

 

[projectSHO89]

Either your battery is not fully charged, is defective, or is otherwise unable to provide full power to the load. Strange things happen when the supplied voltage is too low.

In the future, make certain you identify your venhicle by year, engine, and transmission (if not obvious from the year). There are significant differences and none of us are psychic.

Steve

 

[New to the SHO]

sorry bout that, its a 91 mtx..... U sure its the battery it dont seem like symptoms of just a bad battery it ticks but u think its just not fully charged? I couldnt even bump start it... could it be something with the coil?

 

[projectSHO89]

Using a voltmeter, test the battery.

A fully charged battery with no load will read around 12.6 volts.

Under load (turn on every accessory and light), it should still maintain that voltage within a few tenths of a volt. When the starter motor attempts to pull 150 amps from the battery, the voltage should still stay above 11.5 volts or so.

If the battery tests good, you still need reliable connections from the battery to the rest of the car. Pay particular attention to the ground cable near where it mounts to the engine block. These tend to corrode inside the insulation and cause failures.

For more information, use the advanced SEARCH tool using keyword "starter troubleshooting" and my username. If have previously gone into great detail on identifying these kinds of faults.

Good luck.

Steve

 

[New to the SHO]

thanks

thanks ill try that, do you think it could be the relay up by the cilanoide? Could that make it not start as well?

 

[cmichaelo]

I just installed a new battery and measured a bunch of numbers.

In my experience, only a new and good battery will put out 12.6V with no load. Older batteries that are still good may have outputs as low as 12V.

Secondly, a new and good battery is not gonna stay within a few tenths of a volt when you turn on all accessories. It could drop by 0.5V, especially if not new.

Thirdly, during cranking, the voltage will briefly drop into the 10-11V range.

Michael

 

[rangerj]

Just for grins and giggles check your main ground to the engine block, and the connections at the battery. Make sure you have good clean connections.

Clean the battery posts and the cable connections at the battery, AND at the other ends. Poor connections will cause the problem you describe. So, if the battery is in good shape check the connections as your next step. rangerj

 

[cmichaelo]

Just for grins and giggles check your main ground to the engine block, and the connections at the battery. Make sure you have good clean connections.

Clean the battery posts and the cable connections at the battery, AND at the other ends. Poor connections will cause the problem you describe. So, if the battery is in good shape check the connections as your next step. rangerj

Thanks. That is great advice. Will do so first thing tomorrow. That would explain why the voltage dropped at bit and stabilized after touching one of the connectors on the alternator.

Michael

 

[New to the SHO]

what is that relay on the very upper right hand corner when facing the car its right by that black cover and kinda by the soleniode... its a relay and it has it own holder but i dont know what it does, is that anything to do with starting????