Wiring starter relay

[Yeldaw]

Hi I am trying to understand the wiring on the starter relay for my auto series 3. Should the w2 terminal have an earth wire connected as well as a wire from The auto transmission safety switch or should there only be a wire to the auto switch safety. Is an earth only connected to the W2 terminal on a manual?

Thanks
Dave

[MarekH]

Dear Dave,
You can do either.
If you earth it directly, you can operate the starter anytime you like, but might stall the starter motor if you are in gear.
If you earth it via the gearbox switch, it only allows the circuit to be completed if you are not already in gear, as there is no clutch to dip as a safety with an automatic.
I run mine through a hidden anti-theft switch.
kind regards
Marek

[Yeldaw]

Thanks Marek that's what I thought, I like the idea of the anti theft switch.
I have been having an intermittent problem with my car stalling when warm and occasionally running badly when cold. The last time it happened the starter relay failed and I noticed the relay is linked to the electronic ignition system. I think it goes to the ballast resistor, so I am hoping there was an intermittent problem in the relay and replacing it will have solved my problems with the stalling. Fingers crossed because it has been driving me mad

Dave

[MarekH]

Dear Dave,
Stalling when warm or running not very well when cold has nothing to do with the starter relay.

The starter relay has only two functions:- 1/ it provides a moderately high current to the bendix on the starter motor (which then engages the mega-high current to the starter motor once the pinion is meshed with the flywheel), and 2/ it provides 12v to the coil directly via a straight pass through the ballast resistor during cranking only rather than the normal route through the ballast which goes via a low ohmage resistor to limit the coil voltage under normal running.

As soon as you stop cranking and the key drops back to the normal ignition running position, the starter relay ceases to have any function whatsoever.

Aside from probably wiggling the connections at the ballast resistor end, you almost certainly haven't cured your normal running problems by replacing the starter relay.

kind regards
Marek

[Yeldaw]

Hi Marek I was thinking that maybe if the feed to the ballast risistor was not disengaging properly because of a breakdown of the relay it would cause the ballast resistor/ coil to overheat but agree I am clutching at straws. So far I have replaced the dizzy cap, coil, ignition leads, spark plugs and ignition module plus resighted it from the engine to a cooler area and I was still having a problem. The coil and the ignition module (ab14 type from he engine) do seem to be hot when it stalls.

Dave