IansPlatinum
Active member
- Joined
- Jul 23, 2018
- Location
- Texas
Ok TB gurus,
Here's a fun one.
Problem: intermittent non-start. No cranking, no clicking, nothing.
Background info:
New ignition switch 1 year ago (Volvo brand)
Jumped neutral safety switch blue/yellow wires with a crimp
1 year old Optima yellow top
Issue started back in may 2019, happening maybe a total of 5 times since then
Diagnostic findings at time of non-start:
My diagnostics indicate that voltage is 'leaking' from the starter solenoid circuit to ground, which is why I'm not seeing the full voltage at the blue/yellow terminal.
The big question is, however, is that how it is supposed to be??
Should the starter be able to start with just 10V at the spade terminal? I thought the blue/yellow solenoid wire is just supposed to get the armature moving, and then the positive terminal at the back of the starter takes over to power the actual cranking of the engine.
Should there really be only 10 ohms between negative terminal and blue.yellow spade when key is at pos 3? I feel like it should be more... Maybe I'm just measuring the resistance of the computer or whatever else is active when the key is in pos 3?
Maybe the starter solenoid is just weak?
Before anyone comments the inevitable 'put in a new starter and send it', keep in mind, this is an intermittent issue that would be really crappy to pop up on a trail (I'm lucky it was at the gas station and not in the middle of ouachita national forest). I need to be certain that the starter is at fault, and that my wiring harness circuitry is functioning as intended and as designed.
Thanks, sorry for lengthy post.
Here's a fun one.
Problem: intermittent non-start. No cranking, no clicking, nothing.
Background info:
New ignition switch 1 year ago (Volvo brand)
Jumped neutral safety switch blue/yellow wires with a crimp
1 year old Optima yellow top
Issue started back in may 2019, happening maybe a total of 5 times since then
Diagnostic findings at time of non-start:
- Connected voltmeter to battery terminals. 12.98V, freshly shut off engine (just filled up on gas)
- Connected voltmeter to positive terminal on starter, negative battery terminal. 12.98V, exactly same as Battery.
- Connected voltmeter to blue/yellow spade terminal (while disconnected from starter) and negative battery post. 10V, decreasing slowly to 9.7V over the next 30 seconds or so, even when the key was released from position 3 and put to position 2. The 10V only went away when the key was moved to position 0 (or maybe 1?).
- Disconnected battery negative, placed ohmmeter between pink test spade terminal (behind dipstick tube) and positive battery terminal. 20k ohm when key out, door closed. 0.1 ohm when key out driver's door open (is that normal???). Verified behavior by manually switching the driver's door position switch, and observed 20k ohm to 0.1 ohm just as before. Again, not sure if that's supposed to be that way...
- With battery negative still disconnected, I placed ohmmeter from blue/yellow spade connector (off of the starter solenoid) to positive battery terminal, and turned key to position 3.
Measured between 0.0 and 0.2 ohms (it oscillated, average about 0.1 ohm)
Measured 2kohm when key in pos 2 or lower.
***This test seems to indicate that there is not significant resistance in the circuit.
*****This further puzzled me as to why I was only seeing 10V at the blue/yellow spade connector when trying to start. So I did the test below:
- With negative cable disconnected from battery, I placed the ohmmeter on the blue/yellow starter spade connector and negative battery terminal connector (NOT the battery terminal- battery is disconnected).
Measured 2k ohm at key position 2.
Measured 10 ohm at key position 3 [?!]
My diagnostics indicate that voltage is 'leaking' from the starter solenoid circuit to ground, which is why I'm not seeing the full voltage at the blue/yellow terminal.
The big question is, however, is that how it is supposed to be??
Should the starter be able to start with just 10V at the spade terminal? I thought the blue/yellow solenoid wire is just supposed to get the armature moving, and then the positive terminal at the back of the starter takes over to power the actual cranking of the engine.
Should there really be only 10 ohms between negative terminal and blue.yellow spade when key is at pos 3? I feel like it should be more... Maybe I'm just measuring the resistance of the computer or whatever else is active when the key is in pos 3?
Maybe the starter solenoid is just weak?
Before anyone comments the inevitable 'put in a new starter and send it', keep in mind, this is an intermittent issue that would be really crappy to pop up on a trail (I'm lucky it was at the gas station and not in the middle of ouachita national forest). I need to be certain that the starter is at fault, and that my wiring harness circuitry is functioning as intended and as designed.
Thanks, sorry for lengthy post.
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