Problem with starter circuit - help please

[Kerrigan]

The 1971 FairladyZ-L for a while would occasionally just make a single "click" relay-type sound somewhere under the dash when I turned the key to "Start" and the starter didn't do anything.  I would turn the key off, and then try again sometimes with the same result.  Usually it would work the second or third time and the starter would engage.  We replaced the starter, the switch on the end of the ignition tumbler, and checked the battery.  All those checked out okay.  When it just made the click there wouldn't be any electricity at the starter solenoid b/y wire where it connected to the solenoid tab.  I  jumped from the battery to the solenoid and the starter worked.

The wiring diagrams I have don't show anything between the ignition switch and the starter solenoid except for a lock-out on a car with an automatic tranny; we have a factory 5-speed manual transmission.

Something under the dash makes the "click" sound when I try to start the car with the key.

What I should be looking for causing the problem of no electricity from the ignition switch to the starter solenoid?

Thank you.

[nizm0zed]

i would suggest that perhaps you have an electrical problem???

 

but seriously, if you can consistenly get it to happen, stick your head under the dash while an assistant flicks the key for you.

Touching the body of a relay will help you to isolate which one is clicking.

once you find it, first step is to swap it for a known good one, maybe temporarily use your horn relay? (if it fits)

i would say its likely going to be a dead starter relay. from memory they didnt have the from factory, but they are often fitted over the course of the car's life to prevent excessive wearing of the contacts inside the ignition switch on the back of the barrel.

Another thing that can happen (does it on mine) is if you go too far with the key when starting, its just enough to click the solenoid before going past the sweet spotand cutting power to everything. usually sign of a worn ignition switch.

 

Otherwise, your only other real option is to start following wires and see where they go.

[Zedman240®]

I'd be checking you have a good clean ground connection; either at the battery or where your ground wire attaches (usually at the bellhousing/block) Remember, electricity flowing in DC circuit is a two way street!