There is all kinds of information on the internet on how to use a voltmeter. Since you have a test light that is all you really need to check for power. You just clip the lead to a good conductive metal ground point (any non-painted surface welded or attached to the car body) and place the probe tip on the connection you want to test. If power is getting to that point the light will turn on.
You said you had two switches on the clutch pedal. How do you know which one is for the starter solenoid? If you are sure you have the correct switch and power is getting past the switch then you need to check the wiring going to the starter solenoid. Check the wire color of the small wire going to the starter solenoid and see if it matches one of the wires going to the clutch pedal switch. There is a bad connection on the wire going to the solenoid if you have power after the switch contacts. You need to check both sides of the switch wires to verify power is getting past the switch.
OK thanks again. I’m pretty sure this is the switch to the starter solenoid, as this is pressed when I press the clutch - completing the circuit to allow ignition. The other one is depressed when I push the clutch, so I assume this breaks the circuit and cuts out the cruise control.
I tested the wire going to the starter motor, with the light. It turns on when ignition is applied. Going to check the actual voltage of it, in case it is low power, but this doesn’t make sense - it surely indicates the starter is bad, yet the replacement also did not work…
I did try connecting the starter directly to the positive terminal of the battery, which did not start the starter either. To my mind, this cuts out all the middle wiring (relays, switches etc), and also indicates a faulty starter? Am I missing something obvious?
A voltage is measured between two points. Usually, but not always, the reference point is the chassis ground.
I’d start at the other end. Connect the black probe on the meter or test light to a good secure clean chassis ground. Start at the starter and measure the voltage there. (while someone holds the key in the start position). You should read above 10 volts, or the test light should light brightly. If not, you know there is no voltage getting to the starter. If you do read voltage there, check the ground terminal of the starter, it should read less than one volt, or the light should be off.
If the starter is not moving, you should see the problem then. Either the voltage on the + terminal is low, or the voltage on the – terminal is high. For the latter, that means the ground connection is bad. For the first, you have to go back a step, and repeat for the voltage to the solenoid.
Success! I used the voltmeter and it seemed low at the battery, so I used jumper cables and let it charge for a good 5-10 minutes. Fired right up! I’ll pick up a new battery, hopefully there is not another issue (alternator?), or something else draining the charge. Thanks for everyone’s help, much appreciated.
Assuming you measured low voltage at the battery only when you attempted to start, which does indicate a bad or discharged battery. Because earlier you said the lights etc worked fine…
How old is the battery? You have to ask, what discharged it, or damaged it…
OK, so the new battery was not the fix. Won’t start again. I figured it may have just been grounded from the other car that allowed it to start? So I connected the negative battery to a solid ground - would not start.
Checking electrics and voltages I have the following;
Large power clip on starter connected to -ve battery shows as 12v, key off or cranking
Small power clip on starter connected to negative battery shows as 0v without key, 12v when cranking
_ve battery to ground shows 0v with key or cranking
I’m not sure which wire to check at the ignition switch to check grounding, or what key position to put it in.
I cannot find the starter relay anywhere
Using the light, the ignition switch does seem inconsistent with power through various wires, with the key at differing positions
Battery connections are the first place to begin when you have a “No Crank” situation. Even
if you have a new battery, if the connections are loose, dirty or corroded, you will not be
allowing the full flow of current to pass thru the connections. The connection may be
enough to turn on the lights, but not enough for the huge flow that is needed to operate the
starter. This is where many people say that they know the battery is good….”because the
lights come on”. This is no more a battery test than licking a 9volt battery. It only tells you that there is electricity…not how many volts or the amperage that flows from the battery.
Jump starting may have wiggled the terminal just enough to allow the current to pass and start the engine, but tomorrow you have the same problem.
First remove the cables from the battery and use a wire brush to remove any corrosion and dirt from the battery posts and the cable terminals. There is a tool with a round wire brush for this purpose, found at any auto parts store for less than $10 http://shop.advanceautoparts.com/p/kd-tools-terminal-battery-brush-kdt201/25980576-P?searchTerm=terminal+brush.
Before connecting the cables, apply a coating of di-electric grease to the battery posts this will keep oxygen away from the connection so that it will not corrode as fast.
It is just as important that the other end of the cables also have a clean connection. Remove the positive cable from the battery again so that you do not short anything out. Follow both cables to their far ends, remove this connection and wire brush the connection and the cable terminal clean and retighten these connections.
If there was work done recently, there may have been an “engine to body” ground that was not installed following the work. These grounds normally run from the rear of the engine to the firewall and are uninsulated and most are a braided wire. If any of these are found unattached…reattach them.
Remember….this is not a “Sherman Tank” don’t over tighten the connections.
Tight…tight………………too tight…broke!!!
Measure the starter and solenoid voltage again, this time with the volt meter ground lead on the engine. This will confirm if the engine is grounded. If there is 12 volts at the starter cable and solenoid when in the crank position the starter has failed.
I also retested the voltage at the starter - the small clip only shows voltage when cranking (12v), it is 0v otherwise. The larger clip shows 12v all the time - both of which are normal as I understand it.
Am I missing something with testing the voltage at the starter and solenoid? I only see the 3 cables - always hot, to the ignition and the ground to test, all of which are on the solenoid.
Starting to get a little frustrated, if anyone has more ideas they would be appreciated. Many thanks in advance
I guess my main question now is with the ignition switch. The voltage seemed to be inconsistent when I stuck the voltmeter in the sockets. However, if this was faulty, wouldn’t there be inconsistent power or no power to the starter/solenoid?
If you have 12 volts at the starter cable and 12 volts at the solenoid connector, the starter is bolted to the engine and the engine is grounded the starter should crank the engine. If not replace the starter.
The first test for this problem is put the car on ramps or jackstands, then to connect a volt meter’s + lead on the big terminal directly at the starter, and the - lead directly on the starter’s case. During attempted cranking (ask someone to help) that should measure at least 10.5 volts. It normally won’t read 12 volts like you are measuring b/c there’s 100 amps going down that cable so there’s a significant voltage drop even in normal operation. So I’m thinking you may not be doing the test correctly.
The second test is the same as the first, only on the small starter terminal and the starter case.
These tests must be done with the wires connected to the starter. If you are doing the test by disconnecting the wires for access, that doesn’t accomplish what’s needed.
The other problem you may be having is that your meter may not be able to respond well to changing voltages. Common problem with digital volt meters. When I do this test I use an analog meter so I can just watch the needle move, compared to a mark I’ve put on the dial.
Edit: fyi, I’ve purchased a replacement starter motor before that didn’t work right out of the box.
To clarify, this is how I was doing the tests on the starter motor;
+ve voltmeter touching big nut on hot cable on solenoid, -ve on -ve battery terminal. 12v constantly, key in any position
+ve voltmeter on disconnected black wire (ie on the metal contact that would normally connect inside the solenoid), -ve on -ve battery terminal. 0v unless cranking, then shows 12v.
The smaller wire going to the starter solenoid should only have 12 volts on it when the ignition switch is in the START position. The power turns on the solenoid which then connects the main battery cable to the starter motor windings. There is a heavy duty copper bar inside the solenoid that makes the connection. If you have 12 volts on the small wire while it is connected to the solenoid then the starter should turn. You should hear a fairly load click when the solenoid turns on.
acushing: now measure from the negative battery terminal to the metal case of the starter. You should see <1v under all conditions. If you see a substantial voltage, you have a ground problem.
Ok, played a little this morning.
When I pierced the wire to the solenoid (the one that only has voltage when cranking), the voltage only got to 0.09 when cranking.
I did a voltage drop on the starter (one lead on battery negative, one on the positive big terminal) and it fell by 0.3 (normal?)
I then connected the smaller starter cable (the one that only showed 0.09 when cranking)directly to the +ve terminal on the battery via jump cables and the car fired up fine.
Bill, I just saw your message, will try your test now.
