Engine won't fire - starter solenoid issue?
Posted: Thu Jun 16, 2022 9:11 am
66 toronado. Starter turns but engine won't fire. Replaced coil and points, then found out points are always grounded... even when open.
Looked for grounds. With the key off, the lead connected to the coil + is grpunded.
Per the 66 Toronado wiring diagram, this lead has two branches. The first comes from the ignition switch I terminal. With the key in the off position, this lead should not be grounded. The second branch comes from the starter solenoid R terminal, and is spliced with the ignition switch lead somewhere in the harness. I think, to work properly, this lead should not be grounded.
So, I'm thinking my issue may be because of an internal short in the starter solenoid which grounds the R terminal to the case, or due to a break in the lead which grounds to the vehicle. I'm not yet able to get under the vehicle to remove the leads from the starter solenoid to test either configuration for grounding. Also, I don't know how a short from the R terminal of the solenoid to ground would manifest itself. I believe the voltage to the R terminal is provided through the starter feed once the solenoid is activated; since the starter feed is the largest current draw, I don't know how this short would affect things. The engine appears to crank without a noticeable affect to the starter.
Anyone else seen this? Can anyone provide guidance?
Looked for grounds. With the key off, the lead connected to the coil + is grpunded.
Per the 66 Toronado wiring diagram, this lead has two branches. The first comes from the ignition switch I terminal. With the key in the off position, this lead should not be grounded. The second branch comes from the starter solenoid R terminal, and is spliced with the ignition switch lead somewhere in the harness. I think, to work properly, this lead should not be grounded.
So, I'm thinking my issue may be because of an internal short in the starter solenoid which grounds the R terminal to the case, or due to a break in the lead which grounds to the vehicle. I'm not yet able to get under the vehicle to remove the leads from the starter solenoid to test either configuration for grounding. Also, I don't know how a short from the R terminal of the solenoid to ground would manifest itself. I believe the voltage to the R terminal is provided through the starter feed once the solenoid is activated; since the starter feed is the largest current draw, I don't know how this short would affect things. The engine appears to crank without a noticeable affect to the starter.
Anyone else seen this? Can anyone provide guidance?