engine and drivetrain Electrical - Ignition Gremlins

[zdealey]

First let me say that I'm planning on having a skilled electrician debug my car's electrical issues, but would like to get some feedback from the pros here to expedite getting this car on the road.

 

I finally got my car home and while it was turning over and running smoothly, the stop lights were not working and the fuse for them consistently popped with only AC power engaged.  Nonetheless, the car ran.

 

Fast forward a month and now the car will not even try to crank.  Also, the ballast resistor is glowing with an angry orange coil that seems like a fire hazard.  I realize the car has multiple electrical issues, but would welcome any feedback as to what might be going on.  A short somewhere?  Too much resistance at the coil?  Bad ground?  Demonic possession?

 

PS - The battery was relocated to the trunk and the only engine ground I see is from the frame to the engine block (not my work).

 

 

[thehackmechanic]

Recommend you use the ballast resistor to roast very small hot dogs.

 

I kid, I kid.

 

Seriously...

 

You need to attack these one at a time. Leave the ignition out of it for now.

 

--Use a DVM (digital voltmeter) to test your battery's voltage between its + and - posts. If it's not 12.6 volts, recharge the battery.

 

--Recommend you thoroughly inspect the battery cables for the relocated battery. Disconnect the negative one. Clean both ends of the negative cable. Clean both ends of the ground strap from the engine to the frame. Then disconnect the positive battery cable and clean both ends. Then reconnect the positive, then the negative. 

 

--Then use the DVM check that there's voltage where the positive battery cable is attached to the starter (test with the DVM between there and ground). If there's not close to 12.6 volts there, you have battery cable issues.

 

--Recommend you disconnect the voltage to the coil/ballast resistor.

 

--Then try and start the car. If you don't hear the starter at least trying to turn the engine over, the wire from the ignition to the starter may have fallen off. Check for 12v at that small wire and quick-disconnect terminal on the starter solenoid (not the fat one, the small one). If you don't have 12V there, it's an ignition switch or wiring problem. If you do have 12V there and you hear NOTHING when you turn the key, you could have a bad starter or solenoid, or you could have a voltage drop issue in the positive battery cable. Use the DVM to test voltage from the positive battery terminal to the big terminal on the starter solenoid WHILE SOMEONE TRIES TO START THE CAR. If there's a big voltage drop across the cable, the cable might be bad or the ends corroded. If there's NOT a big voltage drop across the cable, it could be the starter or solenoid.

 

--If the starter tries to crank the car over, hook the ignition back up and see if you can get the car started. If you can, put the DVM across the battery terminals. It should read "charging voltage" -- that is, 13.5 to 14.5 volts, which is the output of the alternator. If instead it reads 12.6 volts, than the alternator isn't charging the battery. If instead it reads over 15 volts, then the regulator isn't probably regulating the voltage.

 

--If it passes those tests, then and only then can you start to look at the other weirdness.

 

Rob

Edited February 4, 2015 by thehackmechanic

[zdealey]

Recommend you use the ballast resistor to roast very small hot dogs.

 

I kid, I kid.

 

Seriously...

 

You need to attack these one at a time. Leave the ignition out of it for now.

 

--Use a DVM (digital voltmeter) to test your battery's voltage between its + and - posts. If it's not 12.6 volts, recharge the battery.

 

--Recommend you thoroughly inspect the battery cables for the relocated battery. Disconnect the negative one. Clean both ends of the negative cable. Clean both ends of the ground strap from the engine to the frame. Then disconnect the positive battery cable and clean both ends. Then reconnect the positive, then the negative. 

 

--Then use the DVM check that there's voltage where the positive battery cable is attached to the starter (test with the DVM between there and ground). If there's not close to 12.6 volts there, you have battery cable issues.

 

--Recommend you disconnect the voltage to the coil/ballast resistor.

 

--Then try and start the car. If you don't hear the starter at least trying to turn the engine over, the wire from the ignition to the starter may have fallen off. Check for 12v at that small wire and quick-disconnect terminal on the starter solenoid (not the fat one, the small one). If you don't have 12V there, it's an ignition switch or wiring problem. If you do have 12V there and you hear NOTHING when you turn the key, you could have a bad starter or solenoid, or you could have a voltage drop issue in the positive battery cable. Use the DVM to test voltage from the positive battery terminal to the big terminal on the starter solenoid WHILE SOMEONE TRIES TO START THE CAR. If there's a big voltage drop across the cable, the cable might be bad or the ends corroded. If there's NOT a big voltage drop across the cable, it could be the starter or solenoid.

 

--If the starter tries to crank the car over, hook the ignition back up and see if you can get the car started. If you can, put the DVM across the battery terminals. It should read "charging voltage" -- that is, 13.5 to 14.5 volts, which is the output of the alternator. If instead it reads 12.6 volts, than the alternator isn't charging the battery. If instead it reads over 15 volts, then the regulator isn't probably regulating the voltage.

 

--If it passes those tests, then and only then can you start to look at the other weirdness.

 

Rob

Thank you for your detailed response, Rob and I'll follow your debugging procedures...starting with acquiring a volt meter.  Electrical issues are obviously everyone's favorite topic, judging by the overwhelming responses to this thread  The build has come way to far to loose it in an electrical fire!

[algon]

Thank you for your detailed response, Rob and I'll follow your debugging procedures...starting with acquiring a volt meter.  Electrical issues are obviously everyone's favorite topic, judging by the overwhelming responses to this thread  The build has come way to far to loose it in an electrical fire!

 

Zach,

 

Swing by my house, I have a multimeter for you.

 

Kevin