Alternator and Starter Motor Shenanigans

[mayalld]

Due to circumstances occupying the entire family (my Mother-in-law had a stroke before Christmas, and passed away a month ago), it has been a late start to the boating year for us. Never before has our first trip of the year been in May.

 

But May it was, for the post winter shakedown cruise. My Vetus started first time, and no engine troubles are reported (just a failed shower drain pump for me).

 

Not so for Stepdaughter and Son-in-Law!

 

Last year, he removed the high output alternator, and returned to the original, because it was shredding belts. On start-up, got the tell-tale screech of a slipping belt at anything over tickover. Cured by disconnecting the battery management system and reconnecting after an hour. Permanent fix installed by way of a switch in the magic lead, to stop the BMS deregulating the alternator until the battery has been charged a bit, and the moisture is gone from the belt and pulleys.

 

But I get ahead of myself. Starting was a problem in itself. Turning the key produced lots of thudunk thudunk, but no whirr whirr.

 

In time honoured "take your life into your hands" mode, a big screwdriver was deployed across the back of the solenoid, and lots of whirr whirr ensued. We even avoided accidentally earthing the screwdriver and welding it in situ.

 

So, feeling pleased with self at having diagnosed the issue as the solenoid contacts. Doesn't actually help with engine starting during weekend out (screwdriver too dangerous in hands of Son-in-Law).

 

No chance of a solenoid on Saturday Morning, so thinking caps on, and box of spares out. Spare battery leads and spare isolator switch look just the job, and duly fashioned into temporary contactor. In fitting, use multimeter to discover that main isolators do not isolate starter feed.

 

Battery off and temporary contactor added. Battery back on, and by jove it works! Turn ignition key, insert red key, and engine turns. Works like a dream on Saturday and Sunday.

 

So, this morning, poised at the ready with red key in hand. Turn ignition key, and it turns over without the temporary switch being actuated. Alleluia, the solenoid has been healed, or has it....

 

Release key, and starter continues to turn. Bugger, the knackered contacts in the solenoid have not only found an electrical path, the have welded themselves on. Mad race to disconnect battery.

 

Thinking cap on REALLY hard now, and eureka moment. If we remove all the positive connection from the feed side of the solenoid, and bolt them all together (including the cable to the temp contactor, the welded solenoid contacts won't matter.

 

It works, the engine starts.

 

So, on return remove solenoid, and marvel at the fact that aftermarket replacements replace about 10 different Lucas Models. What was different about the 10 Lucas solenoids that got them different numbers?

 

So, Auto Electrical Spares say that their "131786 Starter solenoid replaces Lucas TOB128 , 2M113 , M45G" Is also good as a replacement for this 77021. Time will tell. Really hoping that it is internally compatible, so that I can fit it with the plunger from the original solenoid still in place so as to avoid having to unship the actual starter motor.

 

Fun weekend all in all!

[Tony Brooks]

Winding wise it is likely to be identical to all of them, at least electrically and magnetically,  but physically the plastic end cap on the solenoid and contacts will differ. The starter bodies/end brackets also came in some variety so that would account for different stater numbers.