Chongo
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My engine won’t turn over
Battery Trouble shooting:
Take the battery out and take it to a shop, or parts store, and have it load tested, and have them perform a hydrometer test to each cell for the electrolytes specific gravity, (6 cells for a 12 volt battery, a little over 2 volts per cell ), and if it checks out with both test, and there are no dead cells, then the battery is good, a new battery won’t do anything different than the old one.
When the Dash lights up but the engine doesn’t turn over:
Starter:
One of the first quick checks is to crawl under the vehicle with a 20 oz or heavier hammer and tap the starter, you’re not trying to smash it here, with the hammer at the part of the starter closest to the radiator. What this does is disturb the brushes in the starter, so it will momentarily work, basically provide a momentary contact. It won’t fix it. but if it works for a second, and then misbehaves again, chances are it will be the starter. This is a very old trick mechanics have used for almost a century, it’s crude, but effective almost always.
The technical way to do this is to remove the starter and either disassemble it and check the stator and rotor for shorts, brushes and that the cables attached to the brushes are still insulated and not broken, worn or shorted to ground, reassemble and have it bench checked at most parts stores. This process if done professionally will diagnose the starter with about a 90% success rate, it does not load test the starter. Which is the last test with the starter mounted in the vehicle. You must remember one thing with electric starter motors, the 12 volts will spin the starter motor with no load with only few amps, however it is the amperage, ( current ) that does the work to start the engine turning. This is where the bench test is only a 80% test, and not a true load test.
Checking battery cables:
This use to be done at parts stores and repair shops before I was born, and unfortunately is not practiced any longer. And a ohm meter is no help here, as you are checking for load capacity, and not continuity. Normally today what is practiced is, “if in doubt, replace the cables and see if it solves the problem”. This is somewhat successful for a low percentage of the time and the lazy way of guessing at the problem. If it was bad cables, this will fix the problem, if it is something else, you just replaced a good set of cables.
The technical way to do this is to disconnect the negative battery cable from the starter, and make sure it cannot accidentally touch the neg. battery post, this is very important. The take a jumper cable and attach one end to the frame and the other end to the cable @ the starter. Do not connect the neg. cable to the battery, in worst case and scenario it could explode the battery. Using a battery load tester, connect the neg. tester cable to the neg. battery post, and the positive tester cable to the vehicle ground cable, making sure the neg. vehicle ground cable never touches the negative post on the battery. This load tests the battery cables, and you should have the same reading as having the load tester hooked up to the battery only………… How cool is that ?....... If you have lower readings through the cables, then replace the battery cables. Cables can be bad and heavily corroded internally under the insulation coating, at the terminals or broken, etc.
Starter Solenoid:
This unit may have one or two functions depending on the starter design. The solenoid by itself is an electromagnetic switch. It uses a small amount of current to complete, ( close ), a high current connection. When the starter motor first begins to turn, it uses between 350 - 600 amps momentarily, ( depending on the efficiency of the motor design, usually for a small fraction of one second ), until it reaches its design speed, then it only needs around 150 amps to maintain this speed under load. The loss in needed amperage is in a exponential rate, not linear. Now let’s put this into perspective. I own a predator pro welder by thermodyne, and it will produce 10,000 watts of power, or weld @ 300 amps @33.3 volts, ( volts x amps = watts ). Now lets look at a good truck battery, 850 CCA , ( cold cranking amps ), @ 12 volts or 10,200 watts. Hhhmmmmmmm basically the same current as the welder on it’s highest settings, and yes, you can weld with a car battery, but for an extremely short time only. So to put it mildly, the vehicle battery packs quite a wallop for a short period of time. This is why the starter needs a solenoid to make a fast electrical connection so the high current doesn’t weld itself together the first time it’s used. This is the job of the solenoid. In some starter designs the solenoid also engages the drive gear into the flywheel, which I believe is the rover design, and this system is called the bendix portion of the starter. The other design uses a helix grooved shaft which engages the starter drive gear.
If you buy a new starter for your car, it may come with a new Solenoid, or you may have to purchase it separately, which in any case it will be new anyway, so there’s really no trouble shooting here thanks to our throwaway society, with the exception of the activation wire that goes to the solenoid. This is the small dainty 12 ga. - 18 ga. Wire that attaches to it. This should be tested for 12 volts, this wire only transfers about 2 - 4 amps.
Engine block grounds:
This is one of the most overlooked, disregarded and ignored components of the starter system, but I feel the most important, for if it’s not working, you’re going to have issues…..
In the “Solenoid” section, I explained the power of a regular truck battery, it can weld…….. If this ground strap is not on or connected, or is in poor condition all that current from that starter, has to try and get back to the battery somehow. And if it means it has to arc its way though bearings, universal joints needle bearings, ring and pinion gears, torque converters, ECM, or whatever path it chooses, the wake of the currents return path will be filled with the contents of your wallet. Adding an additional ground cable from the engine block to the frame and one from the frame to the body, is only in your best interest.
Hope this helps.......... Chongo
Battery Trouble shooting:
Take the battery out and take it to a shop, or parts store, and have it load tested, and have them perform a hydrometer test to each cell for the electrolytes specific gravity, (6 cells for a 12 volt battery, a little over 2 volts per cell ), and if it checks out with both test, and there are no dead cells, then the battery is good, a new battery won’t do anything different than the old one.
When the Dash lights up but the engine doesn’t turn over:
Starter:
One of the first quick checks is to crawl under the vehicle with a 20 oz or heavier hammer and tap the starter, you’re not trying to smash it here, with the hammer at the part of the starter closest to the radiator. What this does is disturb the brushes in the starter, so it will momentarily work, basically provide a momentary contact. It won’t fix it. but if it works for a second, and then misbehaves again, chances are it will be the starter. This is a very old trick mechanics have used for almost a century, it’s crude, but effective almost always.
The technical way to do this is to remove the starter and either disassemble it and check the stator and rotor for shorts, brushes and that the cables attached to the brushes are still insulated and not broken, worn or shorted to ground, reassemble and have it bench checked at most parts stores. This process if done professionally will diagnose the starter with about a 90% success rate, it does not load test the starter. Which is the last test with the starter mounted in the vehicle. You must remember one thing with electric starter motors, the 12 volts will spin the starter motor with no load with only few amps, however it is the amperage, ( current ) that does the work to start the engine turning. This is where the bench test is only a 80% test, and not a true load test.
Checking battery cables:
This use to be done at parts stores and repair shops before I was born, and unfortunately is not practiced any longer. And a ohm meter is no help here, as you are checking for load capacity, and not continuity. Normally today what is practiced is, “if in doubt, replace the cables and see if it solves the problem”. This is somewhat successful for a low percentage of the time and the lazy way of guessing at the problem. If it was bad cables, this will fix the problem, if it is something else, you just replaced a good set of cables.
The technical way to do this is to disconnect the negative battery cable from the starter, and make sure it cannot accidentally touch the neg. battery post, this is very important. The take a jumper cable and attach one end to the frame and the other end to the cable @ the starter. Do not connect the neg. cable to the battery, in worst case and scenario it could explode the battery. Using a battery load tester, connect the neg. tester cable to the neg. battery post, and the positive tester cable to the vehicle ground cable, making sure the neg. vehicle ground cable never touches the negative post on the battery. This load tests the battery cables, and you should have the same reading as having the load tester hooked up to the battery only………… How cool is that ?....... If you have lower readings through the cables, then replace the battery cables. Cables can be bad and heavily corroded internally under the insulation coating, at the terminals or broken, etc.
Starter Solenoid:
This unit may have one or two functions depending on the starter design. The solenoid by itself is an electromagnetic switch. It uses a small amount of current to complete, ( close ), a high current connection. When the starter motor first begins to turn, it uses between 350 - 600 amps momentarily, ( depending on the efficiency of the motor design, usually for a small fraction of one second ), until it reaches its design speed, then it only needs around 150 amps to maintain this speed under load. The loss in needed amperage is in a exponential rate, not linear. Now let’s put this into perspective. I own a predator pro welder by thermodyne, and it will produce 10,000 watts of power, or weld @ 300 amps @33.3 volts, ( volts x amps = watts ). Now lets look at a good truck battery, 850 CCA , ( cold cranking amps ), @ 12 volts or 10,200 watts. Hhhmmmmmmm basically the same current as the welder on it’s highest settings, and yes, you can weld with a car battery, but for an extremely short time only. So to put it mildly, the vehicle battery packs quite a wallop for a short period of time. This is why the starter needs a solenoid to make a fast electrical connection so the high current doesn’t weld itself together the first time it’s used. This is the job of the solenoid. In some starter designs the solenoid also engages the drive gear into the flywheel, which I believe is the rover design, and this system is called the bendix portion of the starter. The other design uses a helix grooved shaft which engages the starter drive gear.
If you buy a new starter for your car, it may come with a new Solenoid, or you may have to purchase it separately, which in any case it will be new anyway, so there’s really no trouble shooting here thanks to our throwaway society, with the exception of the activation wire that goes to the solenoid. This is the small dainty 12 ga. - 18 ga. Wire that attaches to it. This should be tested for 12 volts, this wire only transfers about 2 - 4 amps.
Engine block grounds:
This is one of the most overlooked, disregarded and ignored components of the starter system, but I feel the most important, for if it’s not working, you’re going to have issues…..
In the “Solenoid” section, I explained the power of a regular truck battery, it can weld…….. If this ground strap is not on or connected, or is in poor condition all that current from that starter, has to try and get back to the battery somehow. And if it means it has to arc its way though bearings, universal joints needle bearings, ring and pinion gears, torque converters, ECM, or whatever path it chooses, the wake of the currents return path will be filled with the contents of your wallet. Adding an additional ground cable from the engine block to the frame and one from the frame to the body, is only in your best interest.
Hope this helps.......... Chongo
