Starter solenoid symptoms?

[ReverendCounter]

If a starter solenoid was kaput, or on the way out, how would that manifest itself? My understanding is that a rapid click indicates a low battery charge rather than a dodgy solenoid. On occasions the engine won't turn over despite a fully charged battery. I'm not sure it its the starter or an aftermarket immobiliser, so I don't know which one to take out - any thoughts please?

[GreenV8S]

It's so easy to diagnose with a simple volt meter that it's really not worth trying to guess.

If the battery isn't over about 12.3V at rest, it needs charging. It should be around 12.6v fuly charged.
If the battery voltage drops below about 8.5-9v while cranking the engine, the battery is either discharged or losing capacity.
If the starter motor receives less than about 0.5v below the battery voltage while cranking, you have a wiring fault. The voltage drop would typically be roughly equal on the positive and negative sides of the circuit.
If the starter motor solenoid is receiving over 12V but not engaging the starter, you have a faulty start motor assembly.
If the starter motor is receiving 12v and engaging but not turning over the engine, you have a faulty starter motor assembly.

[ReverendCounter]

GreenV8S said:

It's so easy to diagnose with a simple volt meter that it's really not worth trying to guess.

Well it is when you know which terminals and wires to probe in each test! Unfortunately I don't so will take in in somewhere if I can get it started.

I appreciate the time you've taken to give some guidance, by the way. Thanks.

Edited by ReverendCounter on Sunday 4th April 19:07

[sliks]

If you have no solenoid engagement, check to see if the smaller wire on the starter is live when ignition is pressed to start.

If it is live measure voltage, if the voltage reading is above 12v the solenoid is not operating as it should it needs changing. Make sure its not in gear and brake is pressed etc if you are underneath the car. It's a dangerous check

If its not live at the smaller starter solenoid wire you have fault in the wiring to the starter or the control circuit which can include the immobiliser.

I agree with Greens, this a rewording of the same thing

Edited by sliks on Sunday 4th April 21:06

[Penelope Stopit]

No point in going through testing the circuit having read your above reply

Are you able to place a piece of wood on the main starter body (the barrel) and hit the wood with a hammer while someone holds the key over in the crank position

Worn out motor brushes do give the symptoms of a failed solenoid, sometimes hitting the starter body bounces the brushes and gets the motor cranking

Solenoids rarely fail apart from the main motor contacts in the solenoid cap burning out

Keep clear of any moving engine parts if you do give the thing a good beating

[red_slr]

Thats what I would do, a few quick (light) taps with a hammer whilst someone else turns the key.
(assuming you are happy with the battery and wiring on the starter are all ok)

[ReverendCounter]

It's intermittent and there's no one to hand to turn the key - however, just found an outfit not too far away who recon starters so will probably just compare the cost to a new one and at least get that part of the ignition query sorted out.

Thanks for the replies and suggestions, they are appreciated.

Incidentally I have hammered it previously with success (not while I was on the key) but on other occasions it has steadfastly refused to start - yet going back a few hours later and it will start immediately. This leads me to think it could be the immobiliser - but I do want a new/recon starter anyway, so I think I'll just bite the bullet.

Edited by ReverendCounter on Sunday 4th April 23:37

[Tony427]

ReverendCounter said:

It's intermittent and there's no one to hand to turn the key - however, just found an outfit not too far away who recon starters so will probably just compare the cost to a new one and at least get that part of the ignition query sorted out.

Thanks for the replies and suggestions, they are appreciated.

Hold your horses Rev.

I had a Volvo S80 with exactly your intermittent problem. Theres a wire, usually on the top part of a solonoid, that provides current to the solonoid from the ignition switch when you want the engine to turn over ie energise the starter.

All you need is for that little spade connector to be dirty, corroded or loose and although it will show 12v on the wire connector itself the connection is too weak and intermittent to give 12v to the solonoid.

Before you do anything take the spade connector off the solonoid and give it and the solonoid terminal a good clean . Then reattach and make sure its tight onto the spade or similar connector.

If you have 12v on the spade connector into the solonoid you then really do have a starter issue that may need a replacement.

[ReverendCounter]

Right - OK thanks, I'll have a good rummage and see the overall state of any corrosion/connectors before I arrange any refurbs etc.