Author Topic: Load shed relay whack??  (Read 3454 times)

Offline Filmcamera

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Load shed relay whack??
« on: October 06, 2018, 08:15:11 PM »
I have been starting to get intermittent starting issues and a new symptom raised its ugly head today.


First past issues.


Once in  a while I would hit the start button and nothing happened, the starter motor did not crank. A little back spin has fixed this so far but I also noticed a couple of other things.


The battery is normally hooked up to a tender most of the time but if I leave it off it drains very fast - (I have a little voltage indicator in the accessory socket above the coils) - after three days the battery is reading 11.9 V and the starting issue is much more likely to happen.  The battery is two and a bit years old so it could be going bad but it also could be something draining it.


We have had three days of non stop rain here this week so I have not been on the bike since the DGR last Sunday, though I did start it up on Wednesday and noticed the two issues above.  I started it again today and though it started right up I had a new issue, namely that the main headlight was off and only flickered on and off as I revved the bike up.  Also the manual fan switch did not work nor did the auxiliary light switch.  As the bike warmed up and I continued to rev it the light slowly became stable and the other switches started to work.


It seems to me there are a number of potential things that could be causing these symptoms and was hoping for a little help to narrow them down.


In no particular order here are the potential culprits as I see them


Bad battery causing low starting voltage
Bad exciter circuit in the alternator
Bad voltage regulator
Bad or failing starter motor
Bad load shed relay
Bad starter button/circuit.


Where would you suggest I focus my efforts to start with and how can I test/narrow down the problems to find the cause?


One last thing, with the ignition on but the bike not running the headlight is steady and stable and all the other switches work.
  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2022 Triumph Tiger 900 Rally Pro
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Offline Scott_

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Re: Load shed relay whack??
« Reply #1 on: October 06, 2018, 09:32:34 PM »
Sounds to me like your starter(brushes) is(are) whack.
When was the last time the brushes were checked..... the load shed relay coil circuit ground is made thru the starter, so if the starter brushes are going out the load shed relay will act whacky...as will the starter.
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Offline Laitch

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Re: Load shed relay whack??
« Reply #2 on: October 06, 2018, 10:21:30 PM »
Bad battery causing low starting voltage
Bad exciter circuit in the alternator
Bad voltage regulator
Bad or failing starter motor
Bad load shed relay
Bad starter button/circuit.
Where would you suggest I focus my efforts to start with and how can I test/narrow down the problems to find the caus
Use this post from kioolt to diagnose a starter problem as Scott_ indicates is likely.
Read this post from rbm for a procedure to help determine what might be draining your battery.

You should perform kioolt's test first.
A two-year old battery should hold a charge longer than yours is. I believe your battery is defective.

I'd charge up the battery, measure the voltage which should be up in the high 12V to mid 13V range, connect it to the moto, disconnect the transmission ground and leave it for a couple of days then measure the voltage again. The voltage should still be in the high 12V range. range and it should start the engine. If it doesn't, it is one of your problems. If it does then after a few days of being connected it doesn't, using rbm's test procedure would be next.
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Offline Filmcamera

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Re: Load shed relay whack??
« Reply #3 on: October 07, 2018, 12:57:45 PM »
Thanks everyone, I opened up the starter motor and found quite a lot of carbon on the brushes.  It is all cleaned off now and it seems the headlight turning off has been cured.


Next I will try and track down the battery drain.
  • San Jose, Costa Rica
  • 1991 K100RS 16v ABS1, 2022 Triumph Tiger 900 Rally Pro
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Offline stokester

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Re: Load shed relay whack??
« Reply #4 on: October 07, 2018, 03:06:19 PM »
Check that battery with a load test.
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Offline The Mighty Gryphon

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Re: Load shed relay whack??
« Reply #5 on: October 07, 2018, 11:51:02 PM »
Checking the brushes and cleaning the damn commutator on the starter should be one of the first things anyone getting a brick should do. 
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