Solenoid Clunks

samfieldhouse

samfieldhouse

Well-Known Member
Joined
18 Sep 2016
Messages
192
Visit site
Recently the starter on my 2GM20 has started to not start, with the solenoid clunking when the switch is pressed.
Maybe 1 in 4 presses it clunks.
The starter battery does need replacing (it’s old) but if lack of power were the issue surely the engine wouldn’t start at all?
A dodgey earth is my other thought.
The starter was refurbished/serviced 2 years ago, not because it was broken but in the interest of preventative maintenance.
I can whip it off and take it in for another service but is a 2 year service interval necessary?

Something is clearly preventing the solenoid from engaging, but what?
 
A solenoid can 'clunk' even when battery is too low to spin engine over ... well more of a loud CLICK ...

Tired batterys could do this ... CLUNK ... CLUNK .. then next time start ...

Starters should go many years before servicing ... all depends on the 'climate' in the engine bay.

Have you tried jumping your domestics to the starter side ... see what happens then (best to disconnect starter battery .. to avoid it dragging other batt down).
 
Can you measure the voltage across the battery terminals when the solenoid clunks? I'd expect it to drop to around 10v, but much less would indicate a dying battery. No or little drop means poor connections, so follow Refueler's cure.
 
Mine is doing similar. Solenoid is working but motor not rotating. Had it rebuilt maybe 10 years ago. These items are getting cheaper so i will just buy a new one then be trouble free for many years to come.
Yours can be replaced for £115 inc. from startermotoralternators.co.uk (first site i googled)
 
Rappey said:
Mine is doing similar. Solenoid is working but motor not rotating. Had it rebuilt maybe 10 years ago. These items are getting cheaper so i will just buy a new one then be trouble free for many years to come.
Yours can be replaced for £115 inc. from startermotoralternators.co.uk (first site i googled)
Click to expand...

First - would it not be prudent to check connectors - battery state etc first before spending money ??

The two most common faults :

1. bad earth on engine
2. Dieing battery
 
Refueler said:
First - would it not be prudent to check connectors
Click to expand...
Most certainly. I used my thermal imaging camera. No bad connections found. Mine is at least 42 years old. Would benefit from a smaller higher powered modern starter.
If an item is an absolute nightmare to get off and reasonably priced i would replace. Saves having to take it off again.
I replaced another on volvo md2030. Pain to get off as motor body was wider than its mounting flange so could not use sockets.
New motor was same power but much smaller making it so easy to fit as i could now use a socket easily.
 
On my starter motor there is a connection between the output of the solenoid and the starter motor.

If you touch the input of the motor with a 12Vdc lead the motor should turn without the solenoid clicking. If the motor turns the battery is OK it could be the contact of the solenoid is damaged.

I had similar issues and checked it this way
 
All good tips thank you.
I’m tempted to whip it off as it’s fairly straightforward and have it serviced.
In the process I’ll check and clean all the connectors, especially the earth.

I do need a new starter battery (it’s 10 years old) - was thinking of an AGM but not sure if the alternator/regulator are compatible?
 
samfieldhouse said:
All good tips thank you.
I’m tempted to whip it off as it’s fairly straightforward and have it serviced.
In the process I’ll check and clean all the connectors, especially the earth.

I do need a new starter battery (it’s 10 years old) - was thinking of an AGM but not sure if the alternator/regulator are compatible?
Click to expand...

Standard alternator ? AGM or plain Lead Acid should be fine ... its when you start into Lithium that the pain starts !!
 
samfieldhouse said:
All good tips thank you.
I’m tempted to whip it off as it’s fairly straightforward and have it serviced.
In the process I’ll check and clean all the connectors, especially the earth.

I do need a new starter battery (it’s 10 years old) - was thinking of an AGM but not sure if the alternator/regulator are compatible?
Click to expand...
At that age I wouldn't be surprised if a new battery didn't cure your problem:unsure:
 
vyv_cox said:
The 3GM loom has four connectors between the switch and the solenoid. A little corrosion in one of these can cause the symptoms you describe. I bypassed the whole lot with a single wire some years ago and never had the problem since.
Click to expand...
If the solenoid is "going clunk" one thinks the circuit is fine for the solenoid excitement, but although it is making the mechanism function, it maybe not making the electric connections for the starter motor excitement.
Also if it is low battery amps it would normally "hunt" .
I would think first check all connections and(as suggested above) try another battery.
 
Rappey said:
Mine is doing similar. Solenoid is working but motor not rotating. Had it rebuilt maybe 10 years ago. These items are getting cheaper so i will just buy a new one then be trouble free for many years to come.
Yours can be replaced for £115 inc. from startermotoralternators.co.uk (first site i googled)
Click to expand...
Less than £60 on ebay for a 2GM 20 starter motor if you require one.
 
billskip said:
If the solenoid is "going clunk" one thinks the circuit is fine for the solenoid excitement, but although it is making the mechanism function, it maybe not making the electric connections for the starter motor excitement.
Also if it is low battery amps it would normally "hunt" .
I would think first check all connections and(as suggested above) try another battery.
Click to expand...
It is a known problem. The solenoid clicks but the current is too low to fully energise it and move the rotor into engagement. In later versions a relay was added, as suggested in post #15.

It is a persistent problem in VW type 2 campers where the solenoid lead runs almost twice the length of the vehicle. Bypassing it by touching a wire from the solenoid terminal to the adjacent battery solves it, as does shorting the terminal to the battery connection on the motor with a screwdriver.
 
Thank you for that; an interesting read.
The approach then is that as the engine start is a push switch I could disconnect the wire at the starter and behind the switch and replace it with a heavier gauge, single wire.
I could also add into that circuit a relay?
 
TBF it's a while since I read it (when the author had a website for his Tartan - I noticed this was on a beneteau site 😄).
IMO, if making the connections good and IIRC replacing a wire with heavier gauge sorts it, I'd prefer not to have a relay as that's additional point of failure. On the other hand they're generally trouble free and cheap...
 
You must log in or register to reply here.

Share this page

Top