Voltage drops when I try to start it...
05-26-12, 09:28 PM
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Voltage drops when I try to start it...
My battery is mounted in the passenger bin with a 2ga (+) cable running to the starter and another (+) cable to the fusible links. The battery is grounded to the passenger seat belt bolt. I've had no problems with this setup for ~5 years.
The battery maintains a ~12.45v reading and the accessories and fuel pump turn on, but when the key turns to Start I get a click from the starter and everything shuts off/dies (except the battery, still holding ~12.45v). Then nothing will turn on for a few minutes (even gauges).
Before trying to start it the voltage at the fusible link is ~12.4v, after trying to start it the voltage drops to <1v. A few minutes later it is back up to ~12.4v.
Do I need another ground somewhere? Could the starter be dead? What else should I test?
Thanks for your help.
The battery maintains a ~12.45v reading and the accessories and fuel pump turn on, but when the key turns to Start I get a click from the starter and everything shuts off/dies (except the battery, still holding ~12.45v). Then nothing will turn on for a few minutes (even gauges).
Before trying to start it the voltage at the fusible link is ~12.4v, after trying to start it the voltage drops to <1v. A few minutes later it is back up to ~12.4v.
Do I need another ground somewhere? Could the starter be dead? What else should I test?
Thanks for your help.
05-26-12, 09:48 PM
#2
Sin City Rotary
I'd clean the connections and re install
^ thats free and never a bad thing to do
if it doesn't help take battery to parts store and have them load test the battery
^ thats free and never a bad thing to do
if it doesn't help take battery to parts store and have them load test the battery
Last edited by 13x; 05-26-12 at 10:01 PM.
05-27-12, 03:37 PM
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I ask because I have minimal tools and no jack+stands in my shared apartment garage at the moment.
The battery is an Optima red top and was new in March, I sure hope that isn't it.
05-27-12, 04:49 PM
#4
Sin City Rotary
both I'd start at battery ... my car is not a daily so I unhook the battery when I park it and sometimes I get a "clack" and no power but if I mess with the connection it is then fine
then the battery itself is unlikely but I wouldn't rule it out .... as a bad connection good have kept it from getting charged properly
then the battery itself is unlikely but I wouldn't rule it out .... as a bad connection good have kept it from getting charged properly
05-27-12, 10:28 PM
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Well it isn't the battery connections, I just checked and re-checked and re-connected, and even with a jump starter clamped on it still gives me nothing. Must be the connection on the starter post...
Thanks guys.
Thanks guys.
05-28-12, 09:20 AM
#7
If it's dropping at the fusible links when you try to start it, that means you have an increased load, that is pulling it down. This could be from a few things:
-Battery can no longer supply current you need. Get the battery load tested.
-Wires or connections are corroded or poor. This causes greater resistance at whatever point the corrosion is. This in turn requires more current to achieve the same potential, usually resulting in a drop in voltage. Normally this drop would be seen on the load end, not the supply, however you could be trying to pull more than your poor little battery can provide.
-Starter is internally shorted somewhere. The starter could have overheated and melted the insulation on some of the windings. This then turns a starter of resistance x into a lower resistance y, or even a dead short to ground. This would certainly cause the system to plunge to ~0V. I would expect to see some sort of conductor heating happening.
If I were you, I'd remove the battery and starter and get the battery load tested and the starter tested. Then you can mess around with wiring.
-Battery can no longer supply current you need. Get the battery load tested.
-Wires or connections are corroded or poor. This causes greater resistance at whatever point the corrosion is. This in turn requires more current to achieve the same potential, usually resulting in a drop in voltage. Normally this drop would be seen on the load end, not the supply, however you could be trying to pull more than your poor little battery can provide.
-Starter is internally shorted somewhere. The starter could have overheated and melted the insulation on some of the windings. This then turns a starter of resistance x into a lower resistance y, or even a dead short to ground. This would certainly cause the system to plunge to ~0V. I would expect to see some sort of conductor heating happening.
If I were you, I'd remove the battery and starter and get the battery load tested and the starter tested. Then you can mess around with wiring.
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05-28-12, 01:42 PM
#8
Old [Sch|F]ool
It's most likely the connection at the starter. That one always gives me fits. Make sure it gets a lockwasher. (I don't disconnect the starter anymore when pulling the trans or the engine, I just unbolt it and bungee it off to the side with a stout rubber one hooked to the left spring. Got bit by a poor connection too many times to mess with a good connection 
)
But still, don't overlook where the cable meets the terminal. I don't know how you made your cables, but that can be tricky to get done "right". Crimps can be poor, solder connections can be faulty, and those cheesy bolt-strap terminals are utter garbage.
What you are seeing happen is, you have a very tiny contact area making contact because of the bad connection, and it will power up the car and voltage gauge just fine. When you try to start, the high current instantly burns out that tiny contact area and you get no connection.
Make it act up, wiggle the cables with the ignition on, see which connection makes the car come back to life.
)But still, don't overlook where the cable meets the terminal. I don't know how you made your cables, but that can be tricky to get done "right". Crimps can be poor, solder connections can be faulty, and those cheesy bolt-strap terminals are utter garbage.
What you are seeing happen is, you have a very tiny contact area making contact because of the bad connection, and it will power up the car and voltage gauge just fine. When you try to start, the high current instantly burns out that tiny contact area and you get no connection.
Make it act up, wiggle the cables with the ignition on, see which connection makes the car come back to life.
05-30-12, 02:36 AM
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But still, don't overlook where the cable meets the terminal. I don't know how you made your cables, but that can be tricky to get done "right". Crimps can be poor, solder connections can be faulty, and those cheesy bolt-strap terminals are utter garbage.
What you are seeing happen is, you have a very tiny contact area making contact because of the bad connection, and it will power up the car and voltage gauge just fine. When you try to start, the high current instantly burns out that tiny contact area and you get no connection.
Make it act up, wiggle the cables with the ignition on, see which connection makes the car come back to life.
What you are seeing happen is, you have a very tiny contact area making contact because of the bad connection, and it will power up the car and voltage gauge just fine. When you try to start, the high current instantly burns out that tiny contact area and you get no connection.
Make it act up, wiggle the cables with the ignition on, see which connection makes the car come back to life.
I got under the car with just the spare jack (maybe I'm paranoid but all the earthquakes in Oakland make that sketchy business to me) and tried tightening the main connection on the starter. When I did that some electrical tape fell away to reveal about a quarter inch of completely exposed copper on the cable running from the starter to the fusible links. It looks like it slipped out of the crimp, which I had done by the nice old guy at the NAPA in my little hometown. It looked great when I put it on but all that vibration must take a real toll.
I'm thinking I should solder, crimp, and shrink-tube the cable terminal, thoughts?
With any luck that'll do it. If not, on to the starter.
Thanks guys.
06-03-12, 08:21 PM
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Alright well I fixed that cable up real nice and there was really no change. All the connections are good now, I guess its on to testing the battery and starter...
Side note: Before this it seemed like my alternator couldn't quite keep up when I had the headlights on, the voltage would sit right around 12. Could doing that on and off for the past couple months have killed my Optima red top battery? I keep telling myself no but maybe I'm in denial here.
Side note: Before this it seemed like my alternator couldn't quite keep up when I had the headlights on, the voltage would sit right around 12. Could doing that on and off for the past couple months have killed my Optima red top battery? I keep telling myself no but maybe I'm in denial here.
06-03-12, 10:49 PM
#12
If it's dropping at the fusible links when you try to start it, that means you have an increased load, that is pulling it down. This could be from a few things:
-Battery can no longer supply current you need. Get the battery load tested.
-Wires or connections are corroded or poor. This causes greater resistance at whatever point the corrosion is. This in turn requires more current to achieve the same potential, usually resulting in a drop in voltage. Normally this drop would be seen on the load end, not the supply, however you could be trying to pull more than your poor little battery can provide.
-Starter is internally shorted somewhere. The starter could have overheated and melted the insulation on some of the windings. This then turns a starter of resistance x into a lower resistance y, or even a dead short to ground. This would certainly cause the system to plunge to ~0V. I would expect to see some sort of conductor heating happening.
If I were you, I'd remove the battery and starter and get the battery load tested and the starter tested. Then you can mess around with wiring.
-Battery can no longer supply current you need. Get the battery load tested.
-Wires or connections are corroded or poor. This causes greater resistance at whatever point the corrosion is. This in turn requires more current to achieve the same potential, usually resulting in a drop in voltage. Normally this drop would be seen on the load end, not the supply, however you could be trying to pull more than your poor little battery can provide.
-Starter is internally shorted somewhere. The starter could have overheated and melted the insulation on some of the windings. This then turns a starter of resistance x into a lower resistance y, or even a dead short to ground. This would certainly cause the system to plunge to ~0V. I would expect to see some sort of conductor heating happening.
If I were you, I'd remove the battery and starter and get the battery load tested and the starter tested. Then you can mess around with wiring.
~T.J.
06-03-12, 11:48 PM
#13
Check your individual Battery Cables, I have seen a similar situation before where all the connections were cleaned and re-cleaned only to find out one of the cables had somehow gotten corroded internally and was not delivering the needed voltage /current did not find the corrosion until we had split up the old cable after it was replaced.
06-10-12, 06:15 PM
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Well, I got the battery load-tested (after quite the ordeal, didn't know it was against federal regulations to bring a car battery on a public bus - even a sealed-gel one). It is good. Picked up a new starter while at the store and just installed it and there was no change. Single-click and dead.
Then I put in the new fusible links I ordered, still nothing.
How can I test the cables for internal corrosion?
There are 12.54v at the battery, and ~12.35v at the starter and fusible links. The car's volt gauge reads under 12v, closer to 11v.
Then I put in the new fusible links I ordered, still nothing.
How can I test the cables for internal corrosion?
There are 12.54v at the battery, and ~12.35v at the starter and fusible links. The car's volt gauge reads under 12v, closer to 11v.
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