Starter Solenoid/Regulator Problems

[TonyTitch]

My SABB HG inboard diesel has a Bosch Dynastart (combined starter motor and dynamo) for starting and charging, controlled via a Bosch starter solenoid/regulator. The latter sometimes only operates when given a good whack, despite a good clean up of the contacts, WD40, etc and may be at the end of its life. A replacement from Bosch costs £247, but I have heard that an equally suitable unit is fitted to a car and costs about £20. Does anyone know if this is so, and if it is, which car. Thanks

 

[Guest]

I have the same system on a Volvo. I know this used to be common as I used to run vintage bikes but havent heard of it on anything post about 1950's though others might have. I am looking at designing a solid state alternative, are you interested in sharing ideas on this?

Roly, Voya Con Dios, Glasson, Lancaster

 

[chippie]

The solid state alternative would work for the regulator but not for the solenoid as it is an electromechanical device.
I have a sachs rotary engine that has a similar setup and has had the regulator adapted from a car. Any competent auto electrician should be able to sketch a wiring diagram. My one doesnt have a solenoid attached as it is engaged via a drive belt. If the problem is in the solenoid sometimes a strip down and good clean out can wok wonders if the solenoid is still electrically sound.
Cheers.

 

[toad]

I have not heard of one fitted to a car but bought a new bosch unit about five years ago for about £70 from a alternator/starter recoditioner,it sounds like the £247 inc the marine mark up.

 

[philip_stevens]

I would suggest that whatever else you do, don't, repeat, don't use WD40 on anything electrical. Once the solvent has evaporated, it leaves a sticky troublesome residue. It is best as a metal protector, but not on moving electrical parts or contacts. For contacts get an electrical solvent cleaner only.

Many moons ago, when I was in the Fleet Air Arm, Rocket/WD40 (as it was then called) was the be-all-to-end-all. It was sprayed into the elecronics/radio bay of helicopters. These went hovering over fields, collecting dust. Next over the sea, collecting spray. Result - short circuit faults. Its use was abandoned and only used to seal the skin of the helo - keeping moisture out of the airframe.

regards,
Philip

 

[[448]]

I had similar trouble on a Vire engine. I cured this by fitting a Lucas alternator (£5 from a scrapyard) into the existing drive belt setup, and scrapping the charging side of the dynastart. This worked beautifully and had the benefit of a much better charging rate. If the solenoid side of the regulator is u/s you could incorporate an independant solenoid from say a Mini and totally bypass the Bosch unit.
Cheers, Dave

 

[DavidTocher]

Or use with the floor mounted push button from an old Mini which directly switched the starter motor. Even less to go wrong!