My partners auto sometimes wouldn't start in park, over the last 6 years or so it got worse and worse until we just had to start it in neutral. We replaced the gearbox insulation mount late last year and voila! Starts in park now so the linkage was out of adjustment, could be another thing worth looking at.

As ratboy has said also could be neutral safety switch out of adjustment or faulty.

Workshop manual is your friend!

And the Top Three causes are :

#3 - ignition switch going out
#2 - starter solenoid getting bad

...and the number one cause: battery cable connections need cleaning.

The latter usually gets very bad within a few days and won't start at all.

Troubleshoot like this to avoid buying un-needed parts:
1. Clean the battery terminals and cable ends. Fasten securely

2. If that doesn't resolve the problem, test the ignition switch by bypassing it:
a. Put car in nuetral and block the wheels
b. Using a remote start cable, connect the starter "S" terminal to the battery +. Press the remote start button to test.
- It it cranks consistently this way, but not when using the key, it is probably the ignition switch. New ones are about $20. It could also be the wiring to the switch.
- If the same problem occurs, it is the solenoid. Datsun starters use welded connectors in the solenoid, so it's not easy to rebuild them. Just buy a new solenoid, or throw a good used starter on there.

If you don't have a remote start cable, you can use a screwdriver momentarily jammed between the starter "S" terminal and large terminal (battery +). Just be very careful, it you short the + to the metal of the engine or starter it can melt the screwdriver.

Of course there are other potential causes, some already mentioned. Best to test first, before buying new parts.

Could be a selector switch problem, these occassionaly get out of adjustment or someting small like a coin etc may be jambing it and stopping it going fully into park. Next time it happens move the selector to neutral and see if it starts then. If it does then either of those is probably the problem.

Edit: What I mean by selector switch is the switch that prevents the car from starting when the selector is in any position other than Neutral or Park.

Quote:
I presume that you mean 1972 B110.
The B10 was a 1967- 1970 thing.

I would agree with dattodude. But, your post states starter has been replaced and I notice you are in the states. If it is a Auto Zone/Checker/PepBoys type of part was it a rebuilt one? I have seen that before on aftermarket units usually the ones that have a lifetime warranty.

My 2 cents worth
Kelmo

the clicking is caused by insufficient battery, or faulty/work-out starter motor solenoid.

I would be 99% sure the starter motor solenoid needs relacing or reconditioning. They are basically an electro magnet with 2 VERY LARGE copper contacts. They erode over time, and need replacing every 10 years if the car is driven daily.

I have a 1972 b10-some- times it will start and sometimes not . when it does not turn over there is a clicking in the auto transmission or close by: after several tries it finally starts. Is there a relay in this auto transmission? starter has been changed.
willie7019= need help[email]