MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Starting problem - engine not turning

My 75 MGB has been garaged for the past 6 months and now it fails to start. The battery is fully charged and when you turn the ignition the starter solenoid just clicks, I think the click is coming from the solenoid.
(The Starter motor is brand new; my thinking was this was the cause of the problem.)

I tried jump starting it which initially didn't work but then suddenly it started. I ran it for a few minutes then successfully started it a couple of time after this. However 5 minutes later all it did was click. I tried jump starting it again but this time without success.

Can anyone suggest a probable cause as I need to get the car on the road whilst the sun is still shinning?
Gary Wemyss

Just checked again and the clicking is coming from the starter relay not solenoid.
Gary W

Gary, this is the classic symptom of a dirty/corroded connection somewhere along the battery to solenoid. More common at the battery.

Cheers

Tony
Tony Oliver

If it is a bad connection at the battery or in the battery cable at the solenoid that will cause lights (ignition warning light, headlights) to dim right down as you turn the key. It also usually causes a chattering solenoid, or at the very least a clonk from it.

With only a click from the relay, nothing from the starter, and if the lights don't dim it is a bad connection in the relay to solenoid circuit.

Check the voltage on the brown and white/brown at the relay with the key turned, and they should both show 12v. If the voltage on the brown drops as you turn the key there is a bad connection involving the *brown* wires at the solenoid. If the brown stays at 12v but the white/brown doesn't rise to 12v then the relay itself is faulty. If the white/brown rises to 12v (check the relay terminal and the spade conenctor on the end of the wire) then the problem is down at the solenoid.

Check the voltage on the white/brown wire connector and the solenoid spade, both should go up to 12v with the key turned. If they do but the solenoid doesn't clonk then the solenoid winding is open-circuit (intermittently, it would seem). If sometimes the voltage on the solenoid spade doesn't go up to 12v then there is a bad connection between there and the relay.

If you find the solenoid *is* clocking when you turn the key, but it doesn't crank the engine, then the solenoid contacts or the motor brushes or a winding are faulty.
Paul Hunt

Occasionally mine fails to start as well. Since the starter can be seen when the hood is up I keep a 3 foot stick in the car with which to tap the starter a couple times and this works for me every time! It starts right up! Bob
Bob Ekstrand

This thread was discussed between 28/06/2009 and 29/06/2009

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.