Starter Relay Problems

[Betazag]

I installed a starter relay in my 82 Zagato earlier this year with great results...until now. I hate having to be pushed off at a car show! I really don't understand the problem; I can jump the battery and the extra juice will do the trick. I have a new battery and it should have plenty of amps to do the job. What can I do besides start cleaning all of the ground contacts in the engine compartment? As always, thanks for all the info you guys have shared. MR

[Fingers]

I pulled the solenoid to bits, cleaned up the contacts, and pulled the little contactor bar off and turned it over so it had a nice clean surface to contact on. I also made sure it struck both the other contacts inside at the same time. I did this about two years ago along wtih the relay mod and haven't had any trouble since.

[SubGothius]

Next time this happens, try this (if things are conveniently located for it):
Pull the wire off the relay that goes direct to the solenoid on the starter (i.e., the lead that would supply current to the starter solenoid when the relay is activated by the key); Make sure your tranny is in neutral and the handbrake is set; Then reconfirm your tranny is indeed in neutral! :D Then with the key turned on (in the run position, not start/crank), touch the end of that lead to the positive (+) terminal of your battery -- prolly a good idea to keep your face away, and use a rubber-grip pliers or something nonconductive to handle the wire!
If the above procedure starts the engine without any problem (when there had been problems immediately beforehand), then the fault is most likely in the relay, ignition keyswitch, or associated wiring/connections. If this does not start the car easily, then your solenoid is the most likely culprit, possibly just the ground wire to the solenoid (which IIRC should most likely be connected to the battery (-) ground terminal, or to the chassis point where the battery ground cable attaches? Not sure, might be mistaken there...).

In my own case, the screws holding the solenoid endcap (where all the terminals are) onto the solenoid body (where the solenoid windings and plunger are) had come loose and fallen out, so the winding wires soldered into the cap were all that was holding it on! Removing the starter+solenoid unit is a real PITA (drain and remove radiator, prolly the battery and tray as well, fumble around blindly under the intake manny to disconnect and extract the starter), but I got my solenoid rebuilt good-as-new by a local alternator supply/exchange for only $~20.