For background, when I had the alternator harness replaced on my '95 993 about a month ago, the dealer said the alternator belt sensor was bad. I said go ahead and replace it, but they couldn't get one quickly. So, I placed an order for a new one. Well, I finally received it after about two weeks.
If you remember, I posted pictures of the alternator belt sensor wheel - the roller that rotates along the belt as it turns. I got a few comments on mine being metal, while theirs are plastic. Well, don't be too jealous!
On comparing the new one to my old one, I noticed that the plastic portion of the roller had broken off and only the metal center portion was left to roll on the belt. Look at the picture below; the old sensor on the left (part no 993.106.035.07) had a roller that was less than an inch in diameter. The new one on the right (part no. 993.106.035.00) had a diameter of about 1.5". Also, if you look hard at the new roller you can see the metal roller case embedded in the total roller unit. So, mine was bad!
<img src="http://boards.rennlist.com/upload/beltsensornew.jpg" alt=" - " />
If you remember, I posted pictures of the alternator belt sensor wheel - the roller that rotates along the belt as it turns. I got a few comments on mine being metal, while theirs are plastic. Well, don't be too jealous!
On comparing the new one to my old one, I noticed that the plastic portion of the roller had broken off and only the metal center portion was left to roll on the belt. Look at the picture below; the old sensor on the left (part no 993.106.035.07) had a roller that was less than an inch in diameter. The new one on the right (part no. 993.106.035.00) had a diameter of about 1.5". Also, if you look hard at the new roller you can see the metal roller case embedded in the total roller unit. So, mine was bad!
<img src="http://boards.rennlist.com/upload/beltsensornew.jpg" alt=" - " />
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
It seems odd to me that your warning light would not have come on due to the lack of contact caused by the missing plastic part of the wheel.
Did you have the old sensor adjusted so that the small metal wheel was riding on the belt?
Did you have the old sensor adjusted so that the small metal wheel was riding on the belt?
</font><blockquote><font size="1" face="Verdana,Tahoma,Arial,Helvetica,Geneva">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Did you have the old sensor adjusted so that the small metal wheel was riding on the belt?</font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Arial,Helvetica,Geneva">Yes, it was riding on the belt (see my old pictures from a few weeks back). You got me curious, so I did a continuity check on the old sensor. Seems that the switch stays closed until the roller pops fully out. So, don't count on this sensor giving any indication of a loose belt - only a broken/popped one.
Three Wheelin'
I posted a few weeks ago asking whether the split in my car's roller was normal (since it looked too "perfect" to be a crack). As Ray's photo shows, the split was in fact a crack. I, too, now have a new one (w/o a crack).
Thanks Ray -- I no longer have metal-roller envy.
Thanks Ray -- I no longer have metal-roller envy.