engine issues
01-05-2012, 04:32 PM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2009
Location: California
Posts: 157
engine issues
I have a 67 with a 289 and toploader 4 spd.
Its been sitting for 6+ months and before that i had driven it around, so I know it worked....
now I turn the key and nothing happens. The lights dont work either. i put a brand new battery in it and still didnt help.
When I try to jump it from battery to starter solenoid(relay), i hear a loud click.
Battery has voltage, solenoid(relay) has voltage, ignition coil has voltage... what should I be looking for???
Its been sitting for 6+ months and before that i had driven it around, so I know it worked....
now I turn the key and nothing happens. The lights dont work either. i put a brand new battery in it and still didnt help.
When I try to jump it from battery to starter solenoid(relay), i hear a loud click.
Battery has voltage, solenoid(relay) has voltage, ignition coil has voltage... what should I be looking for???
01-05-2012, 05:17 PM
#3
1st Gear Member
Join Date: Dec 2010
Location: Washington
Posts: 147
On any loaded circuit the best way to test it is to have it powered and test the components with a volt meter across each component.
Let's say that you want to test the starter for a "no crank" condition.
Start by placing the volt meter negative lead on the negative battery terminal and the positive lead on the positive battery terminal. While trying to crank the engine (loading the circuit) check the voltage. It should be between 9.5 and 12.8.
If the battery checks good then test the first terminal (positive) by placing the positive meter lead on the battery post and the negative lead on the cable clamp. Again while trying to start the engine check the voltage. If it is higher than 0.5 volts then you need to clean the connection or replace it or both. Then after fixing that problem (or if the voltage is between 0.0 and 0.4 volts) then check the cable by placing the positive lead on the cable clamp and the negative lead on the terminal at the cable on the solenoid. While cranking the engine check the voltage. If it is below 0.5 volts then move to the solenoid but if it is higher than 0.5 volts you need to replace the cable or repair the connection from the cable to the termonal. To check the solenoid place the positive lead on the stud of the Positive side of the solenoid and the negative lead on the stud on the starter side of the solenoid. While cranking the the engine check the voltage. If it is between 0.0 and 0.4 volts then it is good. If the voltage is 0.5 or more then the solenoid is bad. Replace it and then go on to the cable to the starter.
Any conductor or switch in a loaded circuit must have less than 0.5 volt drop if it is in good condition. If the voltage is higher it is bad. You could quickly narrow the search by checking the voltage from the positive battery post to the starter all at once and then work backwards with the negativ lead (leaving the positive lead on the battery positive post) until the voltage drop returns to less than 0.5 volts but you need to know that you are checking each point where any two conductors come together and each conductor that carries the load.
If a wire is in perfect condition it will show 0.0 volts when loaded in its circuit. Any load should show battery voltage (you tested that first) when tested under load.
If you get 0.0 volts all the way to the starter (or any load device) and get battery voltage across the load and it doesn't work then you have an open circuit in the starter (load device).
An easy example would be a light bulb. You have 12.5 volts at the battery, all the wires and the switch show a drop of 0.0 volts until you get to the bulb (which is not on) and find a voltage of 12.5 volts when the circuit and switch are on and the bulb doesn't work then you need to replace the bulb. The filiment is broken so it allows 12.5 volts coming to it but there is a negative on the other side. The filiment normally uses 12.5 volts to heat it but since the filiment is broken the voltage doesn't pass so you get a drop of 12.5 volts and no work done.
If the bulb was good it would be burning brightly and you would still get 12.5 volts on the meter because it is using the voltage to make the light and heat. If you get 0.0 volt across the light then you will find the problem on the negative side as a broken or bad connection that will show up as you continue checking on the negative side.
any questions on checking the continuity of a loaded circuit?
Let's say that you want to test the starter for a "no crank" condition.
Start by placing the volt meter negative lead on the negative battery terminal and the positive lead on the positive battery terminal. While trying to crank the engine (loading the circuit) check the voltage. It should be between 9.5 and 12.8.
If the battery checks good then test the first terminal (positive) by placing the positive meter lead on the battery post and the negative lead on the cable clamp. Again while trying to start the engine check the voltage. If it is higher than 0.5 volts then you need to clean the connection or replace it or both. Then after fixing that problem (or if the voltage is between 0.0 and 0.4 volts) then check the cable by placing the positive lead on the cable clamp and the negative lead on the terminal at the cable on the solenoid. While cranking the engine check the voltage. If it is below 0.5 volts then move to the solenoid but if it is higher than 0.5 volts you need to replace the cable or repair the connection from the cable to the termonal. To check the solenoid place the positive lead on the stud of the Positive side of the solenoid and the negative lead on the stud on the starter side of the solenoid. While cranking the the engine check the voltage. If it is between 0.0 and 0.4 volts then it is good. If the voltage is 0.5 or more then the solenoid is bad. Replace it and then go on to the cable to the starter.
Any conductor or switch in a loaded circuit must have less than 0.5 volt drop if it is in good condition. If the voltage is higher it is bad. You could quickly narrow the search by checking the voltage from the positive battery post to the starter all at once and then work backwards with the negativ lead (leaving the positive lead on the battery positive post) until the voltage drop returns to less than 0.5 volts but you need to know that you are checking each point where any two conductors come together and each conductor that carries the load.
If a wire is in perfect condition it will show 0.0 volts when loaded in its circuit. Any load should show battery voltage (you tested that first) when tested under load.
If you get 0.0 volts all the way to the starter (or any load device) and get battery voltage across the load and it doesn't work then you have an open circuit in the starter (load device).
An easy example would be a light bulb. You have 12.5 volts at the battery, all the wires and the switch show a drop of 0.0 volts until you get to the bulb (which is not on) and find a voltage of 12.5 volts when the circuit and switch are on and the bulb doesn't work then you need to replace the bulb. The filiment is broken so it allows 12.5 volts coming to it but there is a negative on the other side. The filiment normally uses 12.5 volts to heat it but since the filiment is broken the voltage doesn't pass so you get a drop of 12.5 volts and no work done.
If the bulb was good it would be burning brightly and you would still get 12.5 volts on the meter because it is using the voltage to make the light and heat. If you get 0.0 volt across the light then you will find the problem on the negative side as a broken or bad connection that will show up as you continue checking on the negative side.
any questions on checking the continuity of a loaded circuit?
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