1994 abs light stays on

I am looking at a 94 abs TCS st1100 to purchase and the abs light stays on. The bike was recently upgraded to the 40 amp alternator. Is it possibly the system needs to be reset? The bike has 17000 miles and looks new. Should I worry much about this?

First thing I'd check is the wires to the sensor and the hub ring.

If the abs light is on there's a malfunction of course...but the brakes will work as normal brakes, just not in abs mode.

Pull the ABS codes to see what's wrong. The procedure is:

1. With the ignition switch off, press and hold the ABS button on the left faring pocket
2. Turn the ignition on and continue holding the button until the ABS light turns off
3. Immediately release the button.
4. The ABS light will now blink out the codes. Ignore the long ones and count the short blinks. The computer can report two codes at the same time, so let it repeat a few times. If you have two codes, there will be a long blink separating them.
5. Write down any codes
6. Press the ABS button momentarily while the computer is in the report out phase to clear the codes.

I had a couple of cases where after clearing the codes it never came back and the ABS worked perfectly. Never did bother to figure out those. Be aware that any time the ABS light is on the ABS system is disabled and you only have conventional brakes.

When I bought my 2010 ST1300, the ABS light stayed on and never blinked. The local Honda shop replaced the front sensor, which was bad, but the light was still there. I had to replace the ABS Computer to fix the issue.

So, if it is blinking, you might have a chance to figure out how to fix it. If it stays on all the time, you might have an ABS computer issue.

Honda wanted $1,100 to "test" and see if it was the ABS computer. I opted not to give them my money and found one on ebay for $200.