1980 Special II - Red Light Flickers

[69mach351]

I literally just purchased a 1980 Special II (it is being delivered in an hour) and this thing runs like a champ, but the red rectangle light on the cluster flickers, then comes on after it has been running for a few minutes, just like when you turn the key on but the bike isn't running. I am assuming this is an electrical deal. The previous owner said that he thought it was a loose connection, so he re-did the plugs to make sure all connections were secure and that didn't work.

Any suggestions would be greatly appreciated. This is by far the oldest bike I have owned and I am a total newbie.

 

[fredintoon]

I literally just purchased a 1980 Special II (it is being delivered in an hour) and this thing runs like a champ, but the red rectangle light on the cluster flickers, then comes on after it has been running for a few minutes, just like when you turn the key on but the bike isn't running. I am assuming this is an electrical deal. The previous owner said that he thought it was a loose connection, so he re-did the plugs to make sure all connections were secure and that didn't work.
Any suggestions would be greatly appreciated. This is by far the oldest bike I have owned and I am a total newbie.

Hi mach,
congratulations on your purchase.
According to Clymers XS650 manual (if you don't have one you best get one) the Special II red light is a brake and tail light failure indicator and sometimes that system gets confused.
What you need to worry about is if it's charging.
Q&D check for that is to point the headlight at a wall and rev up.
If the light gets brighter it's charging. If it don't, it ain't.

 

[69mach351]

Thanks for the info. I will take a look at it and report back. Pretty excited. It should be here any minute.

 

[retiredgentleman]

I literally just purchased a 1980 Special II (it is being delivered in an hour) and this thing runs like a champ, but the red rectangle light on the cluster flickers, then comes on after it has been running for a few minutes, just like when you turn the key on but the bike isn't running. I am assuming this is an electrical deal. The previous owner said that he thought it was a loose connection, so he re-did the plugs to make sure all connections were secure and that didn't work.

Any suggestions would be greatly appreciated. This is by far the oldest bike I have owned and I am a total newbie.

The red light means you have a lower than normal current flow to the tail light.
Could be caused by a few things:
The tail/brake bulb #1157 has been replaced with a lower wattage bulb.
The #1157 bulb has burnt out..................replace with a new bulb.
The "signals" fuse holder/fuse has high resistance from corrosion/oxidation etc.

If the bike still has those old 4 position fuse holders (glass fuses), you should replace with new in line blade type fuse holders asap.

If the alternator is not charging and the battery is weak, that could also cause a red light.

 

[69mach351]

I aimed the headlight into the garage and reved it a little and did not see a noticeable difference in the light (in low position).

The battery was new as of last August. I don't think it would be the battery - the thing starts up immediately without hesitation.

I will change out the taillight (I was planning on changing the housing too at a later date). I will also look at swapping out the older fuses if that has not been done already. If that doesn't work, I will replace the alternator.

 

[retiredgentleman]

I aimed the headlight into the garage and reved it a little and did not see a noticeable difference in the light (in low position).

The battery was new as of last August. I don't think it would be the battery - the thing starts up immediately without hesitation.

I will change out the taillight (I was planning on changing the housing too at a later date). I will also look at swapping out the older fuses if that has not been done already. If that doesn't work, I will replace the alternator.

Headlight brilliance is not a very good test for charging. If you don't have a VOM, you need to buy one. The correct way to test the charging is to connect the VOM leads to the battery terminals.

Start the engine, wait a few minutes, and measure battery voltage at 1200 rpm (looking to see 13 to 13.5 volts).
Rev the engine to about 3000 rpm or more, and you should see approximately 14 volts.

 

[69mach351]

I will look into it. Thanks!

 

[fredintoon]

Headlight brilliance is not a very good test for charging. If you don't have a VOM, you need to buy one. The correct way to test the charging is to connect the VOM leads to the battery terminals.
Start the engine, wait a few minutes, and measure battery voltage at 1200 rpm (looking to see 13 to 13.5 volts).
Rev the engine to about 3000 rpm or more, and you should see approximately 14 volts.

Hi gent.,
Um, Q&D stands for Quick and Dirty.
If the light brightens with revs, yes, you should still plan to buy a multimeter and plan to do a proper check of the electrics.
If the light don't get bright you should buy a multimeter and do the check right effin' now.

 

[fredintoon]

I aimed the headlight into the garage and reved it a little and did not see a noticeable difference in the light (in low position).
The battery was new as of last August. I don't think it would be the battery - the thing starts up immediately without hesitation.
I will change out the taillight (I was planning on changing the housing too at a later date). I will also look at swapping out the older fuses if that has not been done already. If that doesn't work, I will replace the alternator.

Hi mach,
forgive the Senior moment, if the headlight turns on when the engine starts the alternator has to be charging, or at least be producing enough power to trigger the safety solenoid that turns the headlight on.
The headlight will stay lit while the ignition stays on even if the alternator quits after startup so the brightness check is for when you get home and before you turn the key off.
You gotta rev it up to ~2,000rpm to see the light get noticeably brighter.
Alternators ain't cheap. Before you buy another one, check the rotor resistance with the multimeter you should be planning to buy. Above ~4.5 Ohms is good, less than 3 Ohms and it's hooped.
Then check the brush length. Too short and they don't touch the wiper rings. The numbers are in Clymers.

 

[650Skull]

I suggest you read through the links before doing anything. It is hard to know who to believe when there are conflicting answers to a question.

There are a few electrical gurus around here. It will take time to know who they are and RG is up there. I am not one.

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[69mach351]

Thanks for the links! Guess I better get my reading glasses on.

I went ahead and purchased a simple volt meter to hook up (that will stay on the bike. I am going to chop this bike up, but will keep the volt meter hidden so I can monitor it if need be.