3 replies to this topic

[whawes]

One of my minis has been failing to start the past couple of days. The solenoid was clicking every time the key was turned to start, but the starter motor was either turning over very slowly or not at all.

It's an intertia type starter with separate solenoid. I removed the battery, battery clamps and solenoid and gave all contacts a good clean with sandpaper. Having reassembled everything last night I was reading the following voltages:

Battery terminals: 12.87
Battery clamps: 12.87
Solenoid positive terminal: 12.85
Starter motor cable with ignition turned to start: 12.6

These all seem OK to me, but I also got

Starter motor cable with ignition turned off: 2.00

From my (admittedly limited) knowledge of automtive electrics, I was expecting this not to read anything?

This morning I repeated all the readings and got 12.77, 12.77, 12.74 and 12.56 and 2 respectively.

At the same time, I noted when removing the solenoid that there is an earth cable attached to the solenoid positive terminal and the front subframe. Should this be there (and would it explain the reduced voltage at the battery overnight)? I thought the solenoid earth is supposed to be via the body of the unit being attached to the inner wing panel.

The connections at the solenoid, looking from the front of the car, are as follows:

Right hand terminal: Battery positive, Earth lead, 3 x brown cables to spade connectors
Left hand terminal: Starter motor cable

There is also the white/red ignition cable attached via central spade connector on the bulkhead side.

Thanks

Will

[whawes]

Does anyone know the answer to this? Was hoping to get it sorted this morning.

[Dan]

I don't believe there is an earth cable connected as you say it is. If there was then the battery would pretty much explode when you connect it up to the terminals. Investigate that a bit further. Make sure the earth at the battery is well bonded to the bodywork and isn't tired and frayed and the same for the engine earth.

I suspect your solenoid may have failed.

[whawes]

I don't believe there is an earth cable connected as you say it is. If there was then the battery would pretty much explode when you connect it up to the terminals. Investigate that a bit further. Make sure the earth at the battery is well bonded to the bodywork and isn't tired and frayed and the same for the engine earth.

I suspect your solenoid may have failed.

Doh! Voltmeter confirms the cable in question is actually be the positive feed from the battery I'd got it into my head that the other ring connector (brown cable) connected to the positive terminal was the battery positive, but that is taking voltage somewhere else.

For the record, it turned out the starter motor was knackered. Replaced it with a good second hand item and it now turns over at normal speed and starts first time.