Starting Dilemma Tied To The Starter Solenoid

Firstly, based on many posts I have read regarding the Bonneville, the problem I am having is a perennial one that Triumph has never solved.

1. After about 7 years, I am having starting issues with my 2016 Bonneville T100 (only 3300 miles!). Even with a “good” battery (am now on my second new battery), the starting success is intermittent – mostly a fail: all I get are clicks at the starter solenoid.
2. Right out of the box, the 2nd new battery I’ve obtained (180 cca) tested at 12.97V. When installed, it started my motorcycle right away. After running for a minute, I shut it down and after a few seconds, started again. I may have done the once more and then it began failing again: I only got clicks at the starter solenoid. I tried to start the motorcycle again several times thereafter and same result: click at the solenoid !! The battery voltage held to at least 12.6V, which was good. For the hell of it, I had it tested at AutoZone and – unsurprisingly - it came back totally healthy. Then I attached jumper cables from my pickup and the motorcycle started right up !! When the cables were disconnected, it again failed: clicks at the solenoid

Finally, I jumpered across the 2 solenoid posts and it started right up !!!

I’m now doubting that the issue has anything to do with the battery per se.

So my question is:

Is it usual that a 2016 Bonneville with only 3300 miles on it would have a starter solenoid go south ??? My diagnostics are pointing to a failed solenoid.

 

Does anyone know where the “starter relay” is located? I am attaching a pic of what’s under my LH cover. What I have labeled at the Headlight relay is per p.17.23 of the service manual. Other pictures I’ve seen posted on the Internet have this labeled as the Starter relay. ???

I am attaching a series of pictures that describe what I have done since my initial post. Slide 3 is telling; something about these results is wrong.

My understanding is that the (referring to my slides), when the start button is pressed, the circuit across terminals 3 & 4 should energize the coil within the solenoid to internally bridge across terminals 1 & 2, allowing the current from #1 to flow to #2 and on down to the starter. I’m not sure how the “starter relay” is involved and the service manual offers nothing.

Having made the onboard tests I have documented, the only thing left to do is to remove the solenoid, and on the bench energize it while checking continuity/resistance across the #1 & #2 terminals. If I get no continuity, I will know that the solenoid coil is bad. If it checks out, then it may be something else (e.g., the starter relay).

I will post back later.

 

Time to update this thread (this refers to pictures on pictures on post #3):

When I speak of clicks on pressing the starter button, I verified that BOTH the Starter solenoid and Starter/Headlight Cut-out relay are clicking.

I removed these components and performed a complete bench test on both the Starter solenoid and the Starter/Headlight Cut-out relay. They checked out fine, as designed.

To assuage any comments on posts to simply replace the Starter/Headlight Cut-out relay, I did so and the persistent clicks continued without turning over the starter motor.

Another test is to remove the terminal at #3 and check voltage delivered (new battery showing 12.98V).

• With key on only, I get 0.0V
• As the starter button is pressed, I get 12.2V

But I got wondering: “Why remove #3 to make that reading? Why not get a reading with #3 connected to fully simulate what’s happening when the start button is presses?” I expected the same result as before but instead only got 0.32V. Does this tell us anything?

So, to recap:

A. I jumpered across the 2 solenoid posts (#1 & #2) and it started right up !!
B. To effectively bypass the Starter/Headlight Cut-out relay, I bridged across points #1 and #3 with the key on; it started right up !!
C. I attached jumper cables from my pickup and the motorcycle started right up !!

Having thoroughly tested the Starter solenoid and Starter/Headlight Cut-out relay on he bench, Points A, B, & C above best isolate and define the problem, and it seems to have more to do with brute force current (especially B & C) than anything else. Something somehow seems to be preventing adequate current from delivery to the starter. I’m starting to think more about the inscrutable ECM.

Finally, according to the ignition schematic (Service Manual, p.17.111), I might also mention that #4 (which should be a ground for that side of the relay) goes to the kickstand switch and then to the ECM. This may suggest that the ECM may something to do with the proper functioning of Starter solenoid.