Startus Interuptus and blew fuse

I'm hoping fpr some insight please.
My 2014 GRiSO had the startus interuptus problem a few months ago at about 6,500 miles on it. I installed the cable kit that has a 15 amp fuse as part of the kit from MPH Cycles in Houston where I live. A couple of days ago, the bike gave me the same click (now at 7,000 miles) and it wouldn't start. I checked the fuse of the kit and it was blown. Is this ging to be a continuing problem or was this just an anomoly? Is there something I should be checking? A while back (2 months) I noticed my tail and license plate lights were out and it was a 15 amp fuse (B I believe). I presume unrelated.
Any thoughts as to the normality of all of this would be greatly apprecieted.
Happy Holidays.

I suspect it's an anomaly. Double check your connections, especially the earth strap on the starter motor.

Christmas Gremlins ?

When you first hit the start button there is a momentary, very high, amperage draw. If everything is clean and tidy this is so brief it subsides before the fuse can blow but if the connections, especially the earth path connections, are less than perfect the current may stay high enough to blow the fuse.

I'd go over the main earth strap mount by the starter motor and the battery terminals very thoroughly and coat them well with Vaseline or terminal protectant and stick in a 20A fuse for a bit of extra buffering. If you get a short it will still blow almost instantly but it'll give a bit more leeway before it does in normal circumstances.

Pete

As part of the MPH kit, did you also replace the cable that goes from the relay to the solenoid of the starter motor? The original wire is too thin and to be replaced by a 12 gauge wire - this was also communicated by mother Guzzi to the dealers in order to heel the startus interruptus problem. However - as far as I remember - this cable is/was mostly responsible for non-starts when engine warm.

Incredible though that this problem is still present with 2014 production Guzzis. This is just weird.

Beetle, Pete and tjo,
You guys are awesome, thanks. I checked the earth strap-ground and it was tight. I will "lube up" the connections like Pete suggested. The connections to the battery are tight. A 20 amp fuse is on the shopping list now, thanks. tjo, the kit I installed connects to the relay and only one cable runs to the battery from the relay kit. No other connections.
I spoke to MPH Houston today and told them what happened and they said if it happens again, I might have to replace the starter motor. That seems extreme for a bike with 7,000 miles on it.
Stay tuned. I can't thank you guys enough!

Nonsense what ¨MPH said. If their kit does not include the replacement of the cable that goes from position "30" of starter Relay to the Solenoid then it's a rip off.

I would deffinitely suggest again to replace that cable with a 12 gauge cable. It's very easy to do. Just tear off the cable that goes to position 87 of the starter relay and tape it. Put into the same position of the connector the replacement wire that goes directly to the solenoid.

If you need more precise help let me know.

Tom

Errr? Mike and Larry at MPH are really good blokes. While I think the starter diagnosis is probably incorrect the fact is that in almost any case their fix works, it's an easy 'Plug In' and is cheap as chips.

Yes, it's also easy to do a direct feed but most owners hate chopping into a loom, I also hate it as in my whole career all the biggest clusterfucks I've seen have been where people have gone into looms, for whatever reason!

While it may be less than ideal the fact is that in most cases it will cure 'Startus Interuptus'. Don't throw the baby out with the bathwater, just sayin'

Pete

Pete

I always thought that the MPH kit consists of 1) short the relay (position 87) towards the battery with an 15 amp fuse. 2) exchange of the wire that goes form position 30 to solenoid. These are the two main factors why the starter motor might not engage.

I totally agree with you and I would never cut a wire in the loom. Luckily you don't have to do that in order to change the wire in question. Instead you just pull out the female spade (at position 30 of the starter relay - ornage-yellow cable on most if not all C.A.R.C. bikes) and tape it safely to avoid earth contact. Then you prepare the replacement cable with the same female spade connector, pull it into the position of the connector from where you pulled out the original wire.

Now you have to find the other end of the original cable which is on the solenoid (don't worry if it is not orange-yellow like at the connection with the relay) and add another female spade to your new wire.

If you have the original air box in place you will need to take off your Bosch starter motor in order to access the male spade on the solenoid (I have the original air box off so for me it was really easy to access that spot on my Bosch starter without taking it off). It's however not a big deal, two screws only. Connect your new wire to the male spade of the solenoid.

Hope this make sense.

Cheers
Tom

JohnA,

If you are still getting problems after following the good advice above, it might be worth considering if it is the solenoid slightly sticking in the starter is the problem?

I had this problem with mine a few months back. I had fitted the "wire from the solenoid directly to the battery mod" because of a blown fuse a couple of years back and was trouble free until earlier this summer. After the fuse blew this time I stripped the starter motor / solenoid and cleaned and greased all that should be greased, put it all back together and havent had a problem since.

If the solenoid sticks for a fraction of a second it will overload and blow the fuse.

I put up a few pictures a little information about this at the time so if you do a search for "starter motor solenoid strip down" it may be of some help to you.

I have pasted the link below.


[You must be registered and logged in to see this link.]

Actualy both Pete and Tom are right - it all has to do with resistance.

The starter is 1.4 kw rated - thats 116amps, I don't know how hight the inrush current may get, still, the battery is rated 270 cold crancing amps...

If just a tiny 0.1 ohms of resistance is indused in the circuit, then, when the starter draws, lets say 50 amps (only), there will be a loss of 5 volts at this point. (and a loss of 250w, I'll deal with that later, its off-topic)

This resistance can be induced by the thin power cable – Tom’s point - resulting on an undervoltage to the starter, or the solenoid, that like all coils under low voltage will draw more amps, leading to even more voltage drop... endless loop, resulting to as high amperage as the battery can deliver, dangerously overheating the cables, until stopped either by a blown fuse, or by the ECUs timer. This can be solved by using a thicker cable to bypass the thin cable installed by the factory.

Note that the exact same thing (high current) can happen, either if the starter is stuck as Cat wrote, or, if the battery does not have enough power.


This resistance can also be induced by any dirty/oxidized/loose connection – Pete’s point – having the same results as I wrote above, so everything has to be “clean and tidy”. Even if everything looks clean, I clean it again, I also use an electrical contact cleaning spray, even in the relay sockets. Pulling out and reinserting a relay, will scrap off any oxidation from the contacts, some cleaner wont harm…


Pete also wrote “especially the earth path connections”…
While the “power” ( + ) path is dedicated for each load, the “earth” ( - ) path is common, the ECU also uses the same path. So, a voltage loss there will be immediately measured by the ECU, which will halt the starting process due to the under voltage. "Startus Interuptus" - This is what heppened to me sometimes, everytime solved it by cleaning-tightening all earth connections.



Off-topic:
About the watts that are "lost" due to a resistance. Energy can't be lost, its transformed to heat. So, if a cable feels hot at all its lenth, it has resistance, its too thin for the job, if it feels hot close to where its connected, this connection is not good, its either ditry or loose. This apply to all electric circuits - from the cable that goes from the generator to the battery on GRiSO, to the cable that connects my PC to the plug on the wall. If its hot, its not good.