Starting Issues, Electrically on 1987 FXRS

Titch

Titch

Registered User
Anyone have any ideas where else I can investigate?? My FXRS has done the 'electrics gremlin' test to me...
Changed the solenoid, checked power coming live from the handlebar switches, checked most earths.. I can 'hot wire' it to start and it kicks in fine, but finding this 'gremlin' is ..annoying me.
Has anyone had similar issues? I even read somewhere that the push button on the bars is fused.. but can't find that being the case with mine..??
Thanks ,
Titch
 
First off if you say you can hot wire it and it starts, you can assume the starter works!

What you haven't said is how you hot wired it and where and what happens when you try to start it by pressing the button normally, i.e. does it try to turn over, clunk, click or do nothing?

I had over the 17 plus years I owned an '87 FXR plenty of grief periodically with the electric starter and most of it all was down to shitty solenoids!
All the starter button does is connect the electric supply to the solenoid, it does this via a relay to pull the solenoid in to get the starter to turn over.
It is fairly easy to work through the system.
The starter button just operates the relay, it's the relay when operated that makes the connection for the solenoid to pull in.
Once the solenoid has pulled in fully, its the disc inside the solenoid that connects the two large studs to give the connection to the starter motor.
This will require around 100 plus amps to turn the engine over, so any extra resistance in this part of the circuit can make a big difference, thus all the connections and earths need to be spot on!


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Hi there,
thanks for commenting..
My lad has been head scratching this with me, so to be honest, he did the start.. I shall ask him on that. But no, there is no power when the start button on the bars is pressed.. no noise, click nothing... even with the lights on, nothing alters, so no big 'draw' on the power at all?? We have tested the switch too, all seems OK there..
I'll show him what you've said too thanks.
Titch
 
I have had this happen many times. In each case the problem was the solenoid, as above, and with a push button plate on the end of the starter, the starter button on the 'bars is avoided - and so is the solenoid.

I'd advise you to fit one, they are cheap, but it isn't obviously a long term solution. I've found the switches to be sound, as has my relay - but again, this is quick and easy to check or replace if faulty. One issue that did crop up on another bike (a 15 year old triumph this time) was the cabling running along the fork neck and frame spine, where water had got in and corroded the copper. Malachite everywhere upon stripping back the protective tubing.
 
You need a fairly basic meter that can measure DC & resistance in Ohms.
Get the R/H side panel off find the relay, it you have a very early old style one it will be silver, metal cover & round, but more likely black and cubed shape, should have 4 connectors on it.

1 Turn the ignition on, go through the start sequence and listen for the relay to click, no click, most likely not operating, so the bike will not start!

If it clicks you may well have a solenoid /wiring problem but it still could be the relay, take the wire off terminal 87, go through the start sequence and see when holding the starter button if you get battery voltage on terminal 87, if not the relay has failed!

Relay Test, note where each wire goes to on the relay and you will most likely have to remove them to test them.

With the ignition on:-
The wire on Terminal 30 on the relay should have the battery voltage.

The wire on Terminal 85 should be to an earth on the frame. Note this connection by the brake master cylinder is normally made with a self tapping screw and can easily get corroded or loose! (You could test this with meter and measure the resistance between the end of the wire to the battery negative terminal it should be very low but this figure is not really critical)

The wire on Terminal 87 should go to the small screw on the solenoid and should not have any significant reading. (Again you could test the continuity and resistance of this wire but probably not worth it at this stage)

The wire on Terminal 86 should have no significant reading until the starter button is pressed, it should then have the battery voltage all the time the starter button is pressed.

Terminal 87A should have no wire on it.

If these all check out OK, put all the wires back on other than to terminal 87, go through the start sequence and see when holding the starter button if you get battery voltage on terminal 87, if not the relay has failed!

Replace the relay and see if it starts!

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Hi guys,
I fully appreciate the input here. also suspecting 'bad wires' or an earth somewhere too, might be a wire replacement in some area's too. I've also replaced the relay with a brand new one and indeed cleaned up the spade connectors, ( females)
I'll ask good owd Son to have a read of all this, electrics are far more his understanding than mine.. I think it's great that he helps me too!
I'll get back with any results asap thanks,
Titch
 
Titch said:
Hi guys,
I fully appreciate the input here. also suspecting 'bad wires' or an earth somewhere too, might be a wire replacement in some area's too. I've also replaced the relay with a brand new one and indeed cleaned up the spade connectors, ( females)
I'll ask good owd Son to have a read of all this, electrics are far more his understanding than mine.. I think it's great that he helps me too!
I'll get back with any results asap thanks,
Titch
Click to expand...
OK, lets keep it simple and go for the Half Split fault finding technique and work from there.
Remove just one wire, you could remove the wire from the small terminal on the solenoid, it should be a lug held on with a small nut. (If the solenoid is the issue you'll be removing it anyway) of just take the off the other end of that wire on relay terminal 87. (However you are then not testing that wire from the relay to the solenoid!)

1676910101936.png
I've put the correct FXR Evo solenoid picture in now

Turn the ignition on, connect the positive red lead of the meter to the wire you have just removed from the solenoid terminal or terminal 87 on the relay depending on which end you have removed and the meter negative black lead to earth or the negative battery terminal.

Turn the ignition on, press the starter button and if the relay, switch, etc. are all working you should see battery voltage (that is near enough to what you read across the battery directly with the ignition on) all the time the stater button is pressed.

Anything other than this and there is an issue within the wiring back to the starter switch, relay & battery etc.

If you do see battery voltage the issue is then forward and to do with the solenoid and associated wiring and you need to start investigating that side.
 
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Thanks again.. I'm 'seeing' the reasoning.. slowly..
Will get out in w/shop this evening thanks... Solenoid is new too...
 
The Drach Man said:
I have had this happen many times. In each case the problem was the solenoid, as above, and with a push button plate on the end of the starter, the starter button on the 'bars is avoided - and so is the solenoid.

I'd advise you to fit one, they are cheap, but it isn't obviously a long term solution.
Click to expand...
This is not an easy install like the ones for the combined starter/solenoid set up used by H-D '89 onward or even a Shovel head and Softail Evo as the solenoid sits in a different position on the FXR & Touring rubber mount models, inline with the starter and on the FXR under the oil tank, making it more awkward to get at the terminal end.
 
I agree with SJC, but just to help, see the Starter Diagram attached. I know it is not for your bike but the principle is the same.
The path for the power goes: Battery-Starter-Circuit Breaker-Ignition Switch-Ignition Fuse-Stop/Run Switch- Start Switch-Starter Relay-Starter Solenoid. There are several vulnerable points along this torturous route. The Stop/Run Switch and the Start Switch vulnerable to water. The Start Relay Breaking or bad connection. The Ignition Switch (unlikely). The Fuse corroded contacts. The Starter Solenoid (not in your case as it started ok). And of course any wire along the route breaking etc. Don't forget the Earth connections, without them nothing will work.
With a Multimeter and your model Wiring Diagram it shouldn't take too long to find the problem.
If you find any Corroded points, after cleaning, put some Dialectric Grease on them. Brilliant stuff for keeping out water and preventing corrosion
Good Luck. :encouragement:

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Again,
Thanks everyone, input appreciated from y'all. It really shows how keen & knowledgeable you folk are!
As soon as I can get into the w/shop I will be going through every connection and get back to you all on here..
Titch
 
kiwidave said:
This is a great diagram. Never seen one of these in a factory manual.....but then i am normally only looking pre-1986 and 2019 (which thankfully I have not had to try to understand yet). What book year is it from?
Click to expand...
Kiwi, it is a Year 2000 Softail FXST. The Book shows a Complete Wiring Diagram but then shows each section that makes up the whole diagram.
Shown is the Charging and Starting Circuits but there is Lights,Speedo and Indicators. Ignition Circuit etc. Each Section is a lot easier to follow than trawling through the Complete Wiring Harness Diagram. Makes Fault Finding a lot easier. (y)
 
Titch said:
Hi guys,
I fully appreciate the input here. also suspecting 'bad wires' or an earth somewhere too, might be a wire replacement in some area's too. I've also replaced the relay with a brand new one and indeed cleaned up the spade connectors, ( females)
Titch
Click to expand...
Here's some questions that might save a lot of time:-
Did it all work before you replaced the relay and solenoid?
Did you replace them booth at the same time?
Did you replace the solenoid, then the relay because it did not work?
Are all the connections on the right terminals on the relay?
 
We need to know how your boy got it started. Did he connect power directly to the Starter Motor or via the Solenoid? If it was directly to the Starter Motor then the Solenoid is still suspect. If he used the Solenoid then that proves the Solenoid is working and the problem lies elsewhere.
Let us know.
 
Good day all,

Son of owner here, (for whatever reason I can't post myself), list of findings below:
1. solenoid has been replaced with new.
2. We've got 12v at solenoid and starter off push button start closing the circuit
3. Tried multiple relays
 
Well, sorted!
We had a good couple of hours in the w/shop last night.. tidying & cleaning up some existing wiring too.
It turned out that the Earth from the starter relay wasn't that good of an Earth.. multimeter acted as though it was, but after running another wire from where it was earthed to the engine casing, that kicked it all in.... it just goes to show that the obvious sometimes is kicking you in the face..
As said here a few times by many of you all, 'Check & Double Check' so I accept that I foolishly didn't, totally, but I will in the future.. Earths being the most necessary point to complete a circuit after all and it being 'obvious'
So thanks all for the input here again, I can honestly say that I've taken in everything that has been quoted here, and for the operation systematically & electrically, I shall always note all that has been contributed here and will remember all you've all said.
Thanks Again All,
Titch
 
Well done, you cracked it! 👍🏻
Yes Earths are often overlooked and as said without them nothing will work.
 
Indeed, but I think in future I will always check all earths before anything else on electrical problems..
I should have been doing this over the last 40+ years as a 'rule of thumb' really.
Again, thanks to everyone that added to this,... problem I had!
Titch
 
Was it this one at the brake reservoir and was it the original set of the self tapping screw?

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1677067020130.png


Note:- Earlier version with old style relay set up & cabling, multiple earth point circled you can just see the self tapper screw

If so you were lucky as this also could give spurious ignition issues as this is also where the ignition module is earthed, very easy to miss this when trying to track down intermittent faults on the ignition circuit. The third wire in the picture I seem to remember is the earth for the horn under the gearbox,.

What can happen with a poor earth here is the relay and horn still work, but the the higher resistance interferes with ignition module operation so hard to track down, the other two earth point are not marked as to where they are on the circuit diagrams!

I replace that oem self tapper with a stainless steel one, a better solution would probably be a bolt and lock nut!
 
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