machisono

Aloha everyone I have a 1991 C2 with 57.5K on her. I recently replaced the alternator belt sensor to remove that annoying indicator light. However the light is still on so I spent some time with Adrian's book and here are my observations.
Firstly, I noted that the hookup to the belt sensor snaps in but is a bit wobbly, I squeezed the connector firmly to the sensor but the light remained on. I then idled the car for approximately 20 minutes because it was raining here and she doesn't leave the garage when it rains. With the engine idling I was getting 13.1 volts on the multimeter. With the engine off I was getting 12.7 volts at the terminals. At 1200 rpm i was getting a reading of 13.41 and at 3000 rpm only 13.5 volts.
I checked for excess AC voltage (per pg. 384) across the battery terminals and I got a reading of 240mv of AC voltage present.

Is there a new alternator in my future? Thank you in advance for your help.
joe

Rocket Rob

Your alternator voltages sound normal. With your multimeter, can you confirm if the fan belt sensor is registering open and closed? I would need to confirm with the schematics but I seem to remember that that sensor is a simple micro-switch. You should be able to confirm that it passes continuity when depressed.

Navaros911

Voltage over the battery terminals I presume?

At 13.1 it reads a bit low. My alt is acting up when thee weather is hot so I measure very regularly. For my driving it's too low at 13.25 to 13.3... My car does fine from 13.8 onward. The highest I measured was 13.9 ish. If I start the car plenty of times (short trips) the 20 or 30 minute average drive does not charge it quick enough if it's too low.

There is hardly any difference in voltage output at different revs. Then again, I'm not sure if my car operates as it should...

machisono

Hi Rob, the sensor passes continuity when depressed

joe

Rocket Rob

Hmmm.....can you confirm that the light that is on is the fan belt light, not the alternator light? I'm assuming its the fan belt light. With the sensor connected, can you press it so that it clicks, does the dash light turn off? Trying to confirm that the wiring circuit is ok. If it does, then I'm wondering if the switch is not adjusted right. Also, can you confirm that your fan belt tension is proper? A loose belt can turn the light on, if its excessively loose.

machisono

Aloha Rob,
I got it working after moving it back and forth about 10x.s. I also spoke to someone at Pelican who said that it may take a few times in starting the engine and let the belt tensioner roll a bit. When I re installed it started working and that annoying light is out.

Thank you

joe

Rocket Rob

Glad it worked out.