1985 Speedo Troubleshooting - The Saga Continues
05-07-2024, 01:03 AM
#16
Rennlist Member
Thread Starter
Some new updates:
I drained the rear differential and pulled the cover. Here are the results:
- confirmed 8 magnets on the carrier wheel with another magnet.
- pulse sender could only pick up 6 of the magnets as I spun the wheel with the cover off.
- pulse sender could only pick up 4 of rhem With the cover on.
so are the magnets in the carrier wheel weak or do I have an outgoing pulse sender ?
I drained the rear differential and pulled the cover. Here are the results:
- confirmed 8 magnets on the carrier wheel with another magnet.
- pulse sender could only pick up 6 of the magnets as I spun the wheel with the cover off.
- pulse sender could only pick up 4 of rhem With the cover on.
so are the magnets in the carrier wheel weak or do I have an outgoing pulse sender ?
05-07-2024, 01:09 AM
#17
Rennlist Member
I had a situation on a 1989 where after the car had been wrecked and reconstructed the odometer no longer work. Just went on for a number of years until the car came to me and I realized that they put the pulse sensor upside down it was too far away from the magnets. Hard to know what's going on but are you sure that that pickup is facing the right way?
05-07-2024, 11:59 AM
#18
Rennlist Member
Thread Starter
Thanks Kevin - Yes. When testing with cover off. I had the pulse correctly oriented on the carrier unit. I'm wondering if I have a weak magnets and a weak reed switch (pulse sender for those following along!)
05-09-2024, 04:15 PM
#19
Rennlist Member
Thread Starter
I've never opened one of these diffs, but just by hearing your magnet closing the reed switch makes me suspect that the "carrier disk" with the magnets is simply constructed differently.
Looking up the parts for the transmission, I find two different rings.
Carrier Disc With Magnets (UP TO YEAR 85) 92831802402
Carrier Disc With Magnets (FOR YEAR 1986 & Up) 92831802405
If these disks are different enough to require separate part numbers, do they have a common reed switch?
Early reed switch is 92860621000
Later reed switch is 92860621001
Could it be that the later reed switch is required for the later carrier disk?
Looking up the parts for the transmission, I find two different rings.
Carrier Disc With Magnets (UP TO YEAR 85) 92831802402
Carrier Disc With Magnets (FOR YEAR 1986 & Up) 92831802405
If these disks are different enough to require separate part numbers, do they have a common reed switch?
Early reed switch is 92860621000
Later reed switch is 92860621001
Could it be that the later reed switch is required for the later carrier disk?
