Car wouldn't start this morning...electrical short?

[FastDriver]

Hopped in the stang and went to start it up. Everything was normal in the key on position - fuel pressure charged to 40psi and dropped back to 33, all lights came on at full power (did not appear to be a weak battery). When I tried to start the car, I heard a click from the starter solenoid, and then everything went dead as if the battery were suddenly disconnected. About 10 seconds later all power was back to normal. At first I thought it was a dead battery, but I hadn't left any lights on and this battery is relatively new. Also, neither the lights, nor the head unit was dim. I haven't had any similar problems in the past. It's like some kind of electrical short. I was on my way to work, so I didn't really have time to stop and take a close look so I popped the hood, examined the battery terminals - they were clean and snug, I checked the starter solenoid and all of its terminals were clean. One looked a little loose, but it was more than finger tight as I was unable screw or unscrew the nut. What other things should I look at to find a problem which would interfere with starting the car?

Thanks,

Chris

 

[1dark92gt]

if it made a clunk sound it will probably be the solenoid thats wat my problem was atleast

 

[jrichker]

Here's a checklist:

Since some of the tests will bypass the safety interlocks, make sure that the car is in neutral and the parking brake is set. Becoming a pancake isn’t part of the repair process…

Check battery, terminal connections, ground, starter relay switch (also known as solenoid) and starter in that order.

A voltmeter is handy if you are familiar with how to use it to find bad connections. Measure the voltage drop across a connection: more than .5 volts across a connection indicates a problem.
See http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103 for help

1.) Will the car start if it is jumped? Then clean battery terminals and check battery.

2.) Check the battery to engine block ground, and the ground behind the engine to the firewall.

3.) Then pull the small push on connector (red wire) off the starter relay (Looks like it is stuck on a screw). Then jump between the screw and the terminal that is connected to the battery. If it starts, the relay is good and your problem is in the rest of the circuit.

4.) Remember to check the ignition switch, neutral safety switch on auto trans and the clutch safety switch on manual trans cars. If they are good, then the relay is bad. See http://www.autozone.com/images/cds/gif/large/0900823d80195963.gif for 88-90 year cars .OR see http://www.autozone.com/images/cds/gif/large/0900823d80195964.gif for 91-93 year cars. See http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-95 model cars.

5.) Jump the big terminals on the starter relay next to the battery with a screwdriver - watch out for the sparks! If the engine cranks, the starter and power wiring is good. The starter relay is also known as a starter solenoid.

6.) The starter may be hung, loosen up the bolts that hold it on, and give it a good whack with a big hammer. Tighten up the bolts and try again.

7.) If that doesn't work, use a jumper cable from the positive lead on the battery direct to the starter post where the big wire from the relay connects. If it cranks then, it is the power wire from the relay gone bad. This will be hard to do, since there isn't much room to do it.

8.) Pull the starter and take it to Autozone or Pep Boys and have them test it. Starter fails test, then replace it. If you got this far, the starter is probably bad.

 

[FastDriver]

Good stuff jricker. Thanks.

Chris

 

[FastDriver]

It was a loose ground fellas. Thanks again.

Chris

 

[Grn92LX]

Which ground was loose, meathead?

 

[FastDriver]

battery-->block

 

[Stang8URMPRT]

Glad to see ya fixed it. I was gunna mention that a loose ground will do that. It'll be fine until you put a major load on it (like the starter), then all the power goes away. Good job.