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Discussion Starter #1
Hey guys
i have a 2002 roadstar 1600 i am going trough relays quite a bit and dont know why i have tried both oem and after market oem last about a month or two aftermarket last about a week. is there a solution that i am missing? or is there a way to bypass to relay ???
 

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I hope someone with more knowledge on this answers the call. I am not a mechanic or electrician. It sounds like the starter is drawing too much current (brushes worn out). The starter relay i believe is there to protect the rest of the electrical system. I don't believe you want to bypass it. I am not sure how to check the amp draw on the starter. I believe it will blow cheap volt meters.
Good luck and let us know what you find.
 

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Discussion Starter #3
one thing i have not checked its the the draw from the starter i will do that thanks for the reply.i will update on what i find out
 

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the way starter works, the starter button sources about 1A of current to the stater relay

the starter relay closes and it sources about 30A of current to the starter motor

so you see the problem with bypassing the starter relay, the starter button cannot source 30A directly, it would melt (but first it would blow its small fuse).

If the starter has been working with the replacement relays, its possible the starter is drawing too much current, but that should blow the main fuse (30A).

Check and make sure the main fuse has not been bypassed, for example, it blew out and someone wrapped it in alum foil for a road side fix, and never replaced the 30A fuse.

That is the only way I can think of that a bad starter would damage the relay, the fuse is there to protect it, and the wires.

You can get a clamp-on DC amp meter and measure the current in the starting circuit. They are expensive because measuring a DC current is more difficult than AC current. Its possible the starter is spiking the current for a second and its not long enough to blow the fuse, but it is damaging the relay.

or you just had bad luck with a couple of faulty relays? There is a thing with electronic parts called infant mortality: if a part is not assembled correctly, for example poor soldering or a poorly connected heat sink, it will operate for a few hours, then fail. Once a part has worked for several hours its past that infant mortality stage, and will probably work for 20 years.

If you are going to try to measure the current with an inline amp meter, you will need at least a 50A meter to see the 30A current, and if its shorting you will want a 100A DC meter, or the short circuit current will blow your meter out.

If you have not used an inline amp meter before, you have to disconnect one of the wires to the starter (or at the main fuse) and put the meter in series with the wire you took off, so the meter completes the circuit and all the current flows thru it.

If you connect an amp meter across the two starter wires, like you would to measure the voltage, you will blow the fuse in the amp meter, and maybe blow the meter out too.
 

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Discussion Starter #6
I see where that would be an issue with by passing the relay but what if it was on a separate switch? Also if I jump the relay to get it started the bike idles like complete **** untill I put one finger on the relay it calms down.
 

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can you explain that with more detail

you start the bike
the engine cranks normally
the engine starts
but it idles poorly?

if you touch the starter relay the engine runs better?

that is odd, the starter relay should be off and out of the circuit once you let go of the starter button.

Its possible you have a bad connection on one of the wires in the harness that goes to the starter relay, and that other wire is making the bike run poorly till you move it.

Pull the connector off the relay and see if the pins look corroded on the relay or the connector

and check any other connectors nearby that might be moving when you push on that wire.

or get a random finger from somewhere and glue it to the relay

BTW: circuits that only work when an oscilloscope probe is connected... thats a real thing.

you connect the scope to see what the circuit is doing, and it starts working, so the waveform looks great

you take the scope probe off.. it stops working

you put the probe back on... it works again...
 

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astar616 please do NOT install a separate switch for the starter as that will not fix your problem but it could make it worse! If your starter is drawing too many amps (which it sounds like it is) eventually the starter will stop working. The relay going bad is a symptom not the problem! Please have the starter draw checked as the system is designed by (hopefully) smarter people than us and is designed the best way for the functionality of the bike! I hope this helps you decide how to proceed!

Remember to keep the rubber side down & the shiny side up!!
 

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The starter relay handles a lot more than 30amps of current. There is NO fuse between the battery, starter relay, and the starter, it's all direct. Most bikes draw 150-250amps on the starter motor, to get it spinning, once spinning it can be as low as 80amps, but normally the engine will be started at this time, and compression works against you here.

The 30amp fuses on it, are what goes to the bike, but not to the starter itself., it's just a fuseblock that shares the battery post on the relay.

I cannot seem to pull up the specs of the relay itself, but it should be a good 100 to 150amps rating.

On my bike, I didn't have an issue with the starter relay, but the magnets in the starter came unglued, causing high amp draws from the starter.
 

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.... There is NO fuse between the battery, starter relay, and the starter, it's all direct. Most bikes draw 150-250amps on the starter motor, to get it spinning, once spinning it can be as low as 80amps, but normally the engine will be started at this time, and compression works against you here.
....
you are correct - I looked at the schematic for the Road Star starter circuit, the battery is connected directly to the starter relay, which goes directly to the starter

the scanned/copied service manuals that are free online are a bit blurry on the schematics pages - sorry I missed that

there is a main fuse that is in its own holder separate from the other fuses in the fuse box, I was following the wire from that the wrong way.

Im surprised by this - in a car the starter wire has a huge fuse in it, called a fusible link, which keeps the car from going up in smoke if the starter wire gets shorted to the frame.

Maybe the smaller batteries in motorcycles dont have enough cold cranking amps to melt the wire down and start a fire.
 

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Technically it shouldn't blow it, it will cause the contacts to get pitted to the point it doesn't connect cleanly, causing it to overheat and melt.
Happens a lot to the smaller aircompressors (10-40gallon). Happens to HVAC units also, but not a norm for them to have issues (normally it's an issue with bugs).

It's called a solenoid relay, this is cause it's not controlled with a spring or magnet like normal relays, but uses the high power of a solenoid to close it, cause of the high amps in normal usage.
If it's not closed quickly, and cleanly, it will cause sparks, and the sparks will eat holes into the contact area, making it not close cleanly, causing it to make more sparks, till it isn't able to close anymore due to it being too uneven. I test meter will show it as good, cause that is only seeing if it touches, and is not putting a healthy amp load on it like the starter does.

If I read the thread correctly, he is having a problem with it AFTER the bike is started, and not holding the starter button in anymore, at this point it should be open, and that part shouldn't be doing anything at all.
 

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...

If I read the thread correctly, he is having a problem with it AFTER the bike is started, and not holding the starter button in anymore, at this point it should be open, and that part shouldn't be doing anything at all.

"...Also if I jump the relay to get it started the bike idles like complete **** untill I put one finger on the relay it calms down...."

yes, the bike running rough till he physically touches the relay is just weird - something there is making a bad connection - maybe the ground wire, causing the ECM to wack out?
 

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Ok, it's making more sense now. Not related to the starter, or technically the relay itself.

I assume it's not the battery wire, as that would affect the starter a LOT. Must be those spade terminals being corroded, or loose. When it's touched, it causes a better connection, not causing random brownouts.
 

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"...Also if I jump the relay to get it started the bike idles like complete **** untill I put one finger on the relay it calms down...."

yes, the bike running rough till he physically touches the relay is just weird - something there is making a bad connection - maybe the ground wire, causing the ECM to wack out?
There is no ground wire there, just power wires.

Also, what exactly is *jumped*. I was assuming the relay was jumped out, that goes to the starter, but maybe the battery+ to the wireharness was jumped out?
 
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