Help me diagnose electrical issue

-
RockinRobin

RockinRobin

Well-Known Member
Joined
May 15, 2013
Messages
1,249
Reaction score
911
Location
Corsicana, Tx
Yesterday after going enough rounds to get into the finals my car wouldn't start and the batteries were drained. Today, after letting it cool down overnight the batteries showed 11.9 volts and as soon as I turned on the safety switch the starter began turning. After doing this 3 or 4 times, the starter remained off and I could run the starter normally.
Does this sound like some kind of internal short inside the starter?
(Mopar mini starter)
 
RockinRobin said:
Yesterday after going enough rounds to get into the finals my car wouldn't start and the batteries were drained. Today, after letting it cool down overnight the batteries showed 11.9 volts and as soon as I turned on the safety switch the starter began turning. After doing this 3 or 4 times, the starter remained off and I could run the starter normally.
Does this sound like some kind of internal short inside the starter?
(Mopar mini starter)
Click to expand...

What's the "safety switch" ? Battery disconnect? Sounds like a short to power to the starter. I would inspect the wiring going from switch to starter relay.
 
What do you have for starter wiring, I assume from the disconnect that you have the battery trunk mounted? Are you using a second Ford relay to fire the starter?

This could also be a fault in the starter relay wiring IE the small wiring from the key, pushbutton whatever.

It is rare that a starter can stick energized but could happen

Not enough details. What question are you asking? Why are the batteries dead? Do you even run a charging system? How old / have you tested the batteries?
 
Starter solenoid stuck from cranking with low voltage.
Low voltage,high current and long arc during contact.
 
Best solution is to have a second battery on charge, swap it between runs. Low voltage affects lots of things.
 
Not enough info. If you don't have a charging system, the batteries are down. If you do have, then either it was not run enough (as with oversize pulley) and not charged enough, or there might be something wrong with the charging system. What did you do different that now the batteries are down. Maybe one of the batteries is going bad AKA shorted cell, etc.

I doubt there is a "short" but there might be a drain/ draw. That is easy to figure out. Put a light in series with the battery cable, and if it doesn't light or lights dim, put your multimeter in there starting with the highest current scale.

What I'd do:

Charge up the batteries and have them load tested. If the pimply faced kid comes out with a tester he can hold in one hand, it is the wrong kid/ wrong place/ wrong tester. You want a high current load tester otherwise known as a "carbon pile" load tester.

Then get a battery back in, and do as above---looking for a drain.

Next find out why the batteries are down, if they test ok, and if there is no drain. As I said "what are you doing different" and you still haven't give up any details.

So far as the starter sticking we still don't know why, you haven't answered any questions. It may just have stuck, or maybe not How is the condition of the wiring "generally." Has there been any trouble, smoke, shorts, "meltage" in the past? Are the harnesses stock or what? And what condition, generally is that all in?

Hell it might even be something wrong with the igntion switch/ starter relay. If it happens again try pulling off the "start" wire push on connector at the relay WITHOUT disturbing the relay. If it remains cranking, tap the relay with a screwdriver. If no change, quick as you can, unscrew the big "square terminal" and pull that wire off. If it STILL cranks it is in the starter.

IT IS EVEN POSSIBLE that the solenoid wire/ terminal on the starter is loose or otherwise laid down and jumpered itself to the main battery terminal.

And I asked you before DO YOU RUN a separate Ford relay?
 
Last edited:
67Dart273 said:
Not enough info. If you don't have a charging system, the batteries are down.
>>No charging system. No alternator. It gets charged between passes and remains plugged into a charger when not at the track.<<
What did you do different that now the batteries are down.
>>Nothing. I did notice it seemed to take longer to charge the batteries between passes at this last race. The batteries ar 3 years old.<<
Maybe one of the batteries is going bad AKA shorted cell, etc.

I doubt there is a "short" but there might be a drain/ draw. That is easy to figure out. Put a light in series with the battery cable, and if it doesn't light or lights dim, put your multimeter in there starting with the highest current scale.

What I'd do:

Charge up the batteries and have them load tested.
>>Working on that.<<
If the pimply faced kid comes out with a tester he can hold in one hand, it is the wrong kid/ wrong place/ wrong tester. You want a high current load tester otherwise known as a "carbon pile" load tester.
>>Will ask about that.<<

Then get a battery back in, and do as above---looking for a drain.

Next find out why the batteries are down, if they test ok, and if there is no drain. As I said "what are you doing different" and you still haven't give up any details.
>>No details to give. I didn't do anything different this time out.<<

So far as the starter sticking we still don't know why, you haven't answered any questions. It may just have stuck, or maybe not How is the condition of the wiring "generally."
>>Wiring is in good shape. Main positive cable to starter is encased in a heat protective sleeve from the starter terminal back about 4 feet. Wire to relay is also in heat wrap.<<
Has there been any trouble, smoke, shorts, "meltage" in the past?
>>No.<<
Are the harnesses stock or what? And what condition, generally is that all in?
>>Good condition, nothing stock<<
Hell it might even be something wrong with the igntion switch/ starter relay. If it happens again try pulling off the "start" wire push on connector at the relay WITHOUT disturbing the relay. If it remains cranking, tap the relay with a screwdriver. If no change, quick as you can, unscrew the big "square terminal" and pull that wire off. If it STILL cranks it is in the starter.
>>Starter relays are cheap. I bought one today.<<

IT IS EVEN POSSIBLE that the solenoid wire/ terminal on the starter is loose or otherwise laid down and jumpered itself to the main battery terminal.
>>Will check.<<
And I asked you before DO YOU RUN a separate Ford relay?
>>No<<
Click to expand...
 
Update: Batteries checked out ok. Installed new starter solenoid. The old one looked very bad and some of the wires leading to it had sections of insulation missing and the bare wire was corroded. New wiring and crimp terminals. Voltage checks at batteries and up front show exact same voltage, which they never did before. After running for 10 minutes with ignition, efi and water pump on the whole time, the voltage up front never dropped below 12.5 volts. Before this it would have been down to 12.0 after 10 minutes. I think the solenoid and the bad wiring were what drained the batteries enough for the car to have voltage too low to start.
Now the car starts fine and voltage stays higher than it used to while running
Will find out for sure at next Friday's test-n-tune.
 
I don't know how far discharged (low) you batteries are/ were, but running that low voltage means the charging system is lame. you seem to have improved things, but you still may have something, IE partially damaged alternator. I would start by charging batteries get them up and then see where you are.

Maybe I don't have to tell you this, but don't let your batteries sit around for a day or three "down" a ways. Keep them charged or they will sulfate, and then be reduced capacity
 
67Dart273 said:
I don't know how far discharged (low) you batteries are/ were, but running that low voltage means the charging system is lame. you seem to have improved things, but you still may have something, IE partially damaged alternator. I would start by charging batteries get them up and then see where you are.

Maybe I don't have to tell you this, but don't let your batteries sit around for a day or three "down" a ways. Keep them charged or they will sulfate, and then be reduced capacity
Click to expand...
No charging system. Drag car. Runs on batteries only and you charge between rounds.
Batteries checked out ok. You always fully charge batteries before you remove them and have them load tested.
When not at the track, the car is on a charger, even when in the trailer.
 
Took it to the track friday night. No electrical issues. Only made 2 passes then had a flat front tire. I didn't want to plug it in the cold and dark so I loaded it up and took it home.
 
You must log in or register to reply here.
-

Back
Top