Intermittent current to starter motor, sometimes OK . . .

[charles000]

1976 Fiat Spider - a very fun car to drive . . . when it's behaving well.

Hi all. This is one of those frustrating problems that only happens "once in awhile", but of course never happens when expected. I've already had to have it towed home once (don't want to have that happen again!).

The problem -
Usually, I turn the key in the ignition switch, the current goes to the starter motor / solenoid, the engine turns over and starts right up.
HOWEVER, every so often, I turn the key . . . and no current to the starter motor / solenoid.
There is plenty of battery current, everything else turns on, lights, radio, all gauges come to life, but nothing to the starter - at all.

Some folks have suggested a bad or intermittent relay? Others have suggested that I "tap" the solenoid on the starter motor, as that may be stuck every so often . . .

So I plead to the collection of experts here - any and all thoughts are welcome.

[124JOE]

ok ill say,try bad gruond
pull and turn all your battery conections
they should be fairly solid from the batt to the chasiss
and the chasiss to the motor and if you dont find anything
after those try tightening up the starter to the bellhousing
that about covers the grounds


HOPE THIS HELPS

[jimincalif]

Your 76 is probably different from my 80, but I had a similar problem. First I disconnected and cleaned all the connections at the starter (disconnect battery first) as well as at the battery. Still had an intermittent failure. Next, the red wire from the ignition switch to the solenoid had an inline connector that was very dirty. Cleaned both sides of this and spread the male pin open for a good tight connection. This all but eliminated the problem, but still once in a while. I believe the problem is the ignition switch as they are apparently somewhat known for this. So lastly I installed a 40 amp Radio Shack relay in the starter solenoid circuit to reduce the current flow thru the switch. It's been almost a year now with no failed starts (knock on wood dash).

[azruss]

if you poke the starter with a stick while trying to start and it pops to life, then the key is probably not the issue. there is a plate inside the solenoid that connects the 2 big lugs. I have rebuilt starters and cleaned up that plate and connection, as well as the solenoid shaft and that solved my starting problems.