Starter Motor

[Guest ali2992]

Sometimes when starting the engine the starter motor will just make a click sound and nothing will happen, yet after repeated tries of the push button it will suddenly catch - however it can also send up blowing through 10amp fuse on the starting circuit - could both of these be the same issue? Is it a starter motor problem or a circuit problem?

[Longboarder]

Can you describe the starter circuit. Ignition switch to relay to solenoid or what? Where is the 10 amp fuse?

 

Nigel

[Guest ali2992]

ignition switch to solenoid, with a 10amp fuse in between

[Longboarder]

Well there's one problem. Unusual to fuse this wire. Current draw for the solenoid will be approaching 10amps to hold it on and spike higher than that initially. So remove the fuse. Make sure the wire is 4mm or so capable of carrying up to 30 amps to be on the safe side.

Even better use a 30 or 40 amp relay switched by the ignition switch to provide the solenoid current and no fuses in its circuit. That should solve the problem of blowing fuses and probably the click/no start. (It also protects the ignition switch contacts by considerably reducing current flow through it. The main relay supplying the fuse box in the pic below is also to protect the ignition switch and is a 70 amp relay in mine.)

When you next feel like getting dirty remove the starter, and clean up and lubricate the solenoid assembly itself.

 

Nigel

 

This is how mine is.

Edited September 20, 2016 by Longboarder

[fry61]

A bad earth or more likely burnt starter solenoid contacts cause your problems, it's possible to strip & clean the solenoid but remember to de-solder the coil lead first -- otherwise you will need to un-wind the coil to make a new tail.

Experience is why I know!!

[Guest ali2992]

Looking at my diagrams i think the fuse is a remnant of the old mx5 starter circuit which had the starter signal also going to the ecu, seeing as i dont have the original ECU then i have no need for this so I will remove it and see what happens. I've checked the earth points, I have yet to check the actual starter itself but I think that is the next step - the solenoid contact was rather corroded and I cleaned it as much as i could but it might need a new connector.

 

With regards to the relay I remember reading somewhere that the mx5 starter motor has the relay and solenoid bundled together on the back of the motor