Bosch Starter Relay

tom3c75

tom3c75

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Cape Town South Africa
When I had to replace the starter relay on my 3C about a year ago, I fitted a cylindrical 150A relay  from a Jap bike.  Works well.  However, I prefer the relay mounting arrangement of the original unit. 

I?ve now purchased the plastic cased Bosch relay 332002161, which I believe is the one with the amp surge protection.  However, it is only rated at 75 amps.    Is this Bosch unit good to use?    Not sure what the rating was of the old metal cased unit, but surely it was not more than 75A.

Another question, are these the correct wiring connections for the plastic Bosch unit?
85 -  Earth
86 ? Switched 12V
30 ? Battery +
87 ? Starter motor

Tom
 
I stopped using plastic cased ones as the contacts inside are less than half the area of the metal clad ones.
I had a couple of plastic ones weld closed under normal starting procedure, meaning I had to scramble to disconnect the battery before it span the starter motor to death.
 
Old metal-case relays were also rated at 75A. 

I've had one of these fuse a long time ago while on vacation in the Alps.  Opened it up and cleaned the contact points, it's still in the 3C almost 35 years later!  Never happened again.

piet
 
tom3c75 said:
When I had to replace the starter relay on my 3C about a year ago, I fitted a cylindrical 150A relay 

Another question, are these the correct wiring connections for the plastic Bosch unit?
85 -  Earth
86 ? Switched 12V
30 ? Battery +
87 ? Starter motor

Tom
Click to expand...
Tom
It will work like that but usually better to have the switched on 85 and the earth on 86 as generally speaking in a relay there is a diode on that circuit.

I use the 75A Bosch ones from a K type Beemer not had an issue as yet maybe I'm just a lucky sod.  :o

 
I fitted a car unit from an Austin metro or a land Rover (same unit) under the battery tray, it is huge by comparison and can handle 400 amps. Cost was about a tenner 25 years ago, when certain dealers were asking ?85 for a Bosch relay (its not a solenoid) I needed to replace it last year and bought another, this time it was about ?15.
CLEM

 
Thanks fellas.  I think I'll play it safe then and stick with the 150A relay.   

I've just had my starter field coils redone and definitely don't want to damage them again! 
The sparky did a beautiful job on the rewire - looks very professional and the starter now spins like a demon.    He told me that many relay & starter issues are caused by poor batteries that can't produce sufficient cranking amps.  He was insistent that I get my batteries checked, so I'll be taking three of them to him for load testing.

Tom
 
I use AGM batteries as they have higher cold cranking amps than conventional lead acid batteries, and are around half the weight for superior performance.
 
tom3c75 said:
Thanks fellas.  I think I'll play it safe then and stick with the 150A relay.   

I've just had my starter field coils redone and definitely don't want to damage them again! 
The sparky did a beautiful job on the rewire - looks very professional and the starter now spins like a demon.    He told me that many relay & starter issues are caused by poor batteries that can't produce sufficient cranking amps.  He was insistent that I get my batteries checked, so I'll be taking three of them to him for load testing.

Tom
Click to expand...
Not to mention starter clutches  :o :o :o
 
Grant said:
I stopped using plastic cased ones as the contacts inside are less than half the area of the metal clad ones.
I had a couple of plastic ones weld closed under normal starting procedure, meaning I had to scramble to disconnect the battery before it span the starter motor to death.
Click to expand...

Had the same very unpleasant issue last year..
Culprit was the Bosch 0 332 002 150 unit.
 

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I fitted this one to my bike. Its a 75amp plastic one.

https://www.amazon.de/dp/B004Z0WCGG/ref=pe_3044161_185740101_TE_item

I am worried now. Where could i obtain a suitable 150 Amp relay ?
 
TheWrongTrousers said:
I fitted this one to my bike. Its a 75amp plastic one.

https://www.amazon.de/dp/B004Z0WCGG/ref=pe_3044161_185740101_TE_item

I am worried now.
Click to expand...

giphy.gif
 
Would any one like to point me in the direction of a suitable higher capacity relay  ?

Would this do - for example ?

https://www.altecautomotive.co.uk/relay-4-pin-12vdc-200-amp-peak--100-amp-continuousbr-altry2136-09-921-p.asp

Or this ?
http://www.vehicle-wiring-products.eu/product.php/648/high-current-relays
 
Greg Parish said:
This relay comes with a bracket to bolt straight onto the Laverda 3c https://damclassicracing.com.au/71306993-1-starter-relay-12v-dc-with-bracket/
Click to expand...

Hi Greg. That starter relay (Hitachi MS5A-181) is used on a whole bunch of Ducati models and other bikes. I can't find a current rating for it anywhere on the web. It's just listed as suitable for xxx model of Ducati, Cagiva, or whatever. Pedantic gits like myself like to know the specs of parts we buy. Is there any current rating on the relay itself or the packet it comes in?

Cam
 
Sorry. Nothing printed on the Solenoid.
Suffice to say that to see any solenoid after being in service for 20+ years before faulting is probably a good indication of the suitability of the product for the application, and the bracket has been custom made to bolt straight onto the Laverda.
 
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