Le Mans2 Starter Issue Help

I have posted thes call for help in the “General Discussion” area and now realise I was in the wrong section, so apologies for the duplication.

Hi All,
Not sure if I am the right section of the Forum (now know I wasn’t!) but would appreciate help with a starter issue on my LM2.
Some years ago I put the bike into storage doing all the recommended prep for this situation, e.g. disconnecting the battery, adding some oil to the bore top end etc.
I am now in the process of putting it back on the road. Apart from a spring clean and service, checking the obvious bits like the operation of the brake callipers, it all seemed the be going to plan.

Purchased a new battery and connected. All the electrics seemed to be Ok (lights, indicators, warning lights ec) until I pressed the starter button and got that ominous click when the battery hasn’t got enough grunt to turn the starter motor over.

Suspected the new battery was at fault but it checked out. Further investigation led me to the starter relay, but where is it? Whilst I initially thought it was on top of the starter motor I realised the attempted start clicking was coming from a small box mounted below the Diode plate rectifier. Upon further inspection I noticed it was emitting a flash (internally), when I pressed the starter button. I assume that was a spark.
Is it supposed to do that or is it a fault? If anybody has experienced something similar and thinks they know the answer I would be grateful to hear. Thanks.

Hello Ajay

The starter relay is not on top of the starter motor, this is the starter solenoid. The starter solenoid gets power from the starter relay then both switches on a heavy current to the starter motor and also engages the starter pnion into the toothed ring on the flywheel making the engine turn.

The starter relay is in different places on different models and can be above and beside the starter solenoid or behind the left hand side panel on others. Yours could be under the tank but I am not sure that this is normal. The sparks maybe coming from the regulator this has three wires to a single plug, red (terminal D+), brown (terminal DF) and black (terminal D-)

The starter relay has a live feed (brown wire to terminal 86) from terminal 30/15 and is opperated by starter button earthing (black/white wire to terminal 85) the other terminal to the coil in the relay. This closes an electro magnetic switch across terminal 30/15 and terminal 87 sending current (brown wire to terminal 30/15) from fuse f2 to the starter motor solenoid (red wire from terminal 87)

I hope that this information will help you identify which is sparking. Neither the starter motor relay nor the regulator should spark when you press the starter button. Please let us know what you find.

Best wishes

To test the starter motor, short an open end spanner across the 2 large terminals on the rear of the solenoid. This should spin the motor over but not engage the engine.
Then take a wire from the battery +ve terminal and touch it onto the small spade connector on top of the solenoid. This should spin the motor over and engage it to turn the engine over. You don’t need the ignition on for those tests.

If all works as it should with those checks, your fault is with the starter relay wiring (it usually is)
Your Le-Mans 2 should be the same as my SP and I easily corrected the fault. I picked a spare fused feed from the fuse box (Red wire in the picture below 3 up from the bottom) This should be permanant live from the battery.


Relay wiring mod1 by Don West, on Flickr

Relay wiring mod1 by Don West, on Flickr[/img]

Connect this to the centre terminal on the starter relay that is situated just below the fuse box. Remove and tape up the brown wire that was on this terminal.
https://flic.kr/p/2iFvwEc
In this picture, you can see both ends of the wire I have added.
I also replaced the wire that goes across to the solenoid, but isn’t really necessary (The other red wire in the picture)

Relay wiring mod2 by Don West, on Flickr

Many thanks Chris and Don for your information and advice. Appreceated. I have been a bit distracted on paracetamol hunting of late but will get back to, hopefully, a virus free (corona or otherwise)project soon. And will report.

Sounds just like one of the really old relays, semi-transparent casing so yes you can see the contacts arcing inside, if at all. Yes below rectifier area near bottom of battery, right side.

EDIT: if been standing a while, suspect “dirty” or loose connections. Also power to the relay comes from ignition switch etc., hence the starter wiring mod to remove that and all associated wiring, and have a separate fuse direct between battery and the relay supply “live” contact connector. The relay coil remains wired as normal.

Hello Chaps. Having been distracted by you know what, I am now persuing my starter problem again (in splendid isolation!).
Motivated by your very helpful advice I did get somewhere but then it went two steps backwards!

Cleaning up the connections seemed to be the best first move. Having taken off the rear brake reservoir to get to the starter relay, the connections to the relay were duely cleaned and low and behold the starter motor turned over.
However, the indicators now don’t work! Also the dreaded “clunk” was back once I had reasembled the reservoir etc. I have enough information from your good selves to once again persue the starter issue, but what to do about the dead indicators?

I am no electronics expert but have check the continuity from the rear indicator units to the three pin block where it all goes into the main harness. All seems OK there, so no dodgy connections, The fact the front indicators are also not working seems to point to the indicator relay as the problem.
If that is indeed the problem, do these units break? Can they be tested? and also where is it located on the LM2?
Any advice and suggestions gratefully received.

You need a decent wiring diagram that you can read and not have to trace wires or translate from Italian. I can supply you with one (see here http://www.motoguzziclub.org.uk/forum/viewtopic.php?f=64&t=16390&sid=94b393ee95bf9a1da4e18285d35da2bd ) or you can get one free from Carl Allison (Google this old tractor Guzzi wiring diagrams)

The Le-Mans electrical system will be identical to that on my SP. The flasher cans are located just above and in front of the master cylinder. You can see them in the second picture I added above. There are two to operate the hazard flashers. It is quite likely that you have disturbed a wire in the spaghetti going in and out of the cans.
Did you try the test I suggested? What were the results? This will detelrmine if the fault lies in the starter, battery or the bikes wiring…

To test the starter motor, short an open end spanner across the 2 large terminals on the rear of the solenoid. This should spin the motor over but not engage the engine.
Then take a wire from the battery +ve terminal and touch it onto the small spade connector on top of the solenoid. This should spin the motor over and engage it to turn the engine over. You don’t need the ignition on for those tests.

Before getting too deep into the various components of the indicators it might be worth checking that the fuse holders are making good contact with the both ends of each fuse. The spring tension can deteriorate with time and cause intermittent faults. It is also worthwhile cleaning and polishing the end of each fuse. In the past I have had the ends of the fuses actually fracture where the holder is supposed to make contact and this caused me to re-wire the rear indicators only later to discover this age related failure. A happy half hour cleaning the fuse box connections may prevent many hours of frustration in the future! Hope this helps. Cheers Phil

Good point Phil.
The indicators are on the bottom fuse, but always a good idea to give them all a good clean every now and again. I put a spot of vaseline on them when refitting.

However, the indicators now don’t work! Also the dreaded “clunk” was back once I had reasembled the reservoir etc. I have enough information from your good selves to once again persue the starter issue, but what to do about the dead indicators?

May be just a coincidence – as Don-Spada says if LM2 is like Spada, does it have a hazard flashers switch? (Should do)

This is a toggle switch and I’ve had trouble with these, the circuit is permanently ‘live’ which causes the contacts to fur up and corrode. Then it stops working. This wouldn’t matter except the current for normal turn indicators also goes through the same switch! Albeit using two different contacts.

I had the exact same problem on my BMW, had to junk the switch and connect the wires directly. Ideally get rid of it, and move the indicators supply wire to an ignition switched source, which will prevent the verdigris problem. Also, scrotes can’t turn your indicators on and walk off smirking while it’s parked.

The Le-Mans 2 does have hazards (at least mine did), the switch is under the instrument console, left hand side.
The wiring to the 2 flasher cans is quite a maze, In the 31 years of owning mine, I never dared touch it!

On my Spada I ripped the hazard switch and second flasher unit out.
Ian

Many thanks Chris, Don, Mike Phil, et al for the info advice.
First of all apologies to Don. Yes, I did carry out your starter motor tests (very useful) which were successful. Hence moving the attention to “dirty” connections. Also confirm I had checked the fuses. All show connectivety but thank you Phil for the very sensible prompt.
And yes MIke, it is one of the old translucent relays and the spark, when the starter button is pushed, is coming from insde the relay. As I said, I did get access to the relay connectors and cleaning them seemed to do the trick, until I reassembled the brake reservior back into place. I am going to retrace my steps and try another battery, just in case. Am contemplating Don’s direct wiring mod but not particularly comfortable in this skill area but never say never.

Chris - I am definately interested in one of your wiring diagrams. If the PDF shows the same attention to detail, thats fine. Your list shows an LM2 with or without “PCB”? At the risk of sounding stupid what is “PCB”. Happy to do a bank transfer or PayPal to cover cost, please advise amount and prefered method.

Onto the indicator issue. I can confirm my LM2 does have the hazard switch.
Reference to “cans” plural confused me until I realised that what looked like one unit in the rubber holder was actually two, either side. I am sure by passing the hazard switch/relay makes sense but not sure my eclectrical eapertise is up to that. Mike: can a ludite manage this job? Anyway first step is to clean all the accessable connectors.

Once again, thanks for all the input. I will report.

PCB = printed circuit board. Some Spadas and LM2’s with the big rubber dash surround have the internal wiring in the form of a PCB rather than separate components. I don’t know enough about when it changed or whether it’s visible from outside. My ‘78 Spada doesn’t have a PCB.
Ian

Spada / LM2 dashboard PCB (used to be a topic on here!) :smiley:

Instrument Console Rebuild

That is the one with the PCB, if it doesn’t have the green circuit board it is earlier (without PCB) have a look and let me know which you would like. Send me your email address via PM and I will send you a pdf copy.

Yep.

Mike: can a ludite manage this job? Anyway first step is to clean all the accessable connectors.

I think in this case, the supply wire to the flasher(s) is on fuse 6, or 5. Which are permanently connected to battery positive. :exclamation: These are at the bottom of the fuse box (or should be). I think you can safely unplug this wire and move it up to one of the top fuse, No. 1, spare blades; fuse #1 does brake lights etc. if memory serves. And the supply comes via the ignition switch.

The doubled-up flasher unit thing I always thought was quite strange, but needed for hazard mode, but it works for the turn indicators so no need to mess with it if you don’t want to.

PM sent

AJ I hope the diagrams were of assistance, if you have any questions fire away :smiley: