I made a post back in January about my non-starting Cobra (GM block, original post at bottom) and received some responses. It's now spring time and the problem has not fixed itself so it's time to revisit it. I've done some more troubleshooting and it indicates a more general electrical problem.
I've found that the trim does NOT work either, and that as soon as I switch on something, say the engine room blower, there is a significant voltage drop - down to below 6V. The gauges don't power up fully and the tachometer doesn't return to 0 when the ignition switch is put in the acc. position.
Voltage drops to zero when I try to operate the trim or the starter, and the trim solenoids don't click.
Also, there is no voltage on the IGN lead which goes from the ignition switch to the tach. With the ignition switch in the start position, there is only about 6V on the purple lead at the starter solenoid (which is placed on the starter motor).
Battery is new and OK. I've checked all fuses I know of, and there is power from the battery to the instrument panel (12V).
Any ideas? Grounding problem at the ignition switch?
/P O Litby
Billgran wrote:
Do not overlook the simple things such as the neutral safety switch > inside the control box or a disconnected yellow/red wire on the key > switch. I am assuming that the gauges power up with the key to ON and > that the trim works OK.>
Bill Grannis> service manager>
"Per-Olof Litby - Practice Mgr - Software, Central/North Europe -> Sun Microsystems" <politby@sun.com <mailtoolitby@sun.com>> wrote> in message news:ct8633$95h$1@new-usenet.uk.sun.com...> Greetings,>
My Cobra engine won't start. Absolutely nothing happens when I> turn the ignition key - no click from the solenoid, and obviously> the starter doesn't crank. The battery is OK. Does this indicate> that the solenoid is shot?>
I guess it theoretically could be the ignition switch but the> instruments come to life so I don't think that's it. What's the> easiest way to diagnose the solenoid?>
"Per-Olof Litby" <politby@sun.com> wrote in message news:_4Rae.135497$dP1.477344@newsc.telia.net...>I made a post back in January about my non-starting Cobra (GM block, >original post at bottom) and received some responses. It's now spring time >and the problem has not fixed itself so it's time to revisit it. I've >done some more troubleshooting and it indicates a more general electrical >problem.>
I've found that the trim does NOT work either, and that as soon as I > switch on something, say the engine room blower, there is a significant > voltage drop - down to below 6V. The gauges don't power up fully and the > tachometer doesn't return to 0 when the ignition switch is put in the acc. > position.>
Voltage drops to zero when I try to operate the trim or the starter, and > the trim solenoids don't click.>
Also, there is no voltage on the IGN lead which goes from the ignition > switch to the tach. With the ignition switch in the start position, there > is only about 6V on the purple lead at the starter solenoid (which is > placed on the starter motor).>
Battery is new and OK. I've checked all fuses I know of, and there is > power from the battery to the instrument panel (12V).>
Any ideas? Grounding problem at the ignition switch?>
/P O Litby>
Billgran wrote:>
Do not overlook the simple things such as the neutral safety switch >> inside the control box or a disconnected yellow/red wire on the key >> switch. I am assuming that the gauges power up with the key to ON and >> that the trim works OK.>> Bill Grannis>> service manager>>
"Per-Olof Litby - Practice Mgr - Software, Central/North Europe ->> Sun Microsystems" <politby@sun.com <mailtoolitby@sun.com>> wrote>> in message news:ct8633$95h$1@new-usenet.uk.sun.com...>> Greetings,>> My Cobra engine won't start. Absolutely nothing happens when I>> turn the ignition key - no click from the solenoid, and obviously>> the starter doesn't crank. The battery is OK. Does this indicate>> that the solenoid is shot?>> I guess it theoretically could be the ignition switch but the>> instruments come to life so I don't think that's it. What's the>> easiest way to diagnose the solenoid?>> thanks ahead,>> /POL>>
Not the solenoid! Is a bad connection near the battery. Either bad battery connection or bad cable or corrosion on a connector at the fuse, etc. Take a meter and put one lead on the battery negative post and then when the starter is engaged, go along the positive path from the battery and see where the voltage drops. You can also take a reading from the Negative battery post to the engine block to see if there is a bad ground path.
So this to me indicates either a faulty battery - which seems strange >since I tried a different battery last fall when the problem showed up >the first time and that didn't help - or some problem with the grounding.
I assume it's a new battery as in brand new battery? Off the shelf?
Have you tried jumping the battery from a separate source like a battery charger or jump start box and testing the drop then? The only reason I say that is because of your experiment with the starter solenoid. If you are getting that kind of drop with a direct connection to the battery, then it's got to be the battery.
Have you tested the battery with a real load type tester and not just a volt meter?
"Shortwave Sportfishing" <emaildisguised@askme.com> wrote in message news:tpfq61ts32p5gqp5hqlavl3ctu2pbiun3r@4ax.com...> On Mon, 25 Apr 2005 18:39:45 GMT, Per-Olof Litby <politby@sun.com>> wrote:>
~~ snippage ~~>
So this to me indicates either a faulty battery - which seems strange>>since I tried a different battery last fall when the problem showed up>>the first time and that didn't help - or some problem with the grounding.>
I assume it's a new battery as in brand new battery? Off the shelf?>
Have you tried jumping the battery from a separate source like a> battery charger or jump start box and testing the drop then? The only> reason I say that is because of your experiment with the starter> solenoid. If you are getting that kind of drop with a direct> connection to the battery, then it's got to be the battery.>
Have you tested the battery with a real load type tester and not just> a volt meter?>
Later,>
Tom
Pull the battery connector and clean it really well. Make it shine. If they are the wing nut type connections, clean them and use a nut and washer, that you can put a wrench on.
Open up that 8 pin cluster on top of the engine. Clean up the male pins with very fine sand paper (crocus cloth), then roll the paper up tightly and clean up inside the female contacts.
I have a 1988 305 Cobra and have had to do this every year for some time. The symptoms seem to be the same with me as you're describing. Also, it could be the 50 amp fuse on top of the engine.
Per-Olof Litby 27 April 2005 01:26:45 [ permanent link ]
N.L. Eckert wrote:> Open up that 8 pin cluster on top of the engine. Clean up the male pins> with very fine sand paper (crocus cloth), then roll the paper up> tightly and clean up inside the female contacts.>
I have a 1988 305 Cobra and have had to do this every year for some> time. The symptoms seem to be the same with me as you're describing.> Also, it could be the 50 amp fuse on top of the engine.>
This is the exact same model as mine ('88 305). How do I open that cluster - just pull it apart?
Is that 50A fuse on the starter motor circuit? I don't have a shop manual so I can check the wiring diagrams.
BTW, I forgot to say that in my previous post but the battery WAS dead.
