1979-1993 & 94 Conv [Subscribe to Daily Digest] |
![]() | [Main C900 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: no tach signal at LH conn./why?... Posted by Justin VanAbrahams [Email] ![]() ![]() In Reply to: no tach signal at LH conn./why?..., Ed S, Wed, 24 Oct 2001 20:22:06 Members do not see ads below this line. - Help Keep This Site Online - Signup |
There could be four reasons:
1. The Hall-Effect sensor is dead - you can test this as per the Bentley manual
2. The Ignition Control Unit (ICU) is dead - again, you can test this as per Bentley.
3. The Ignition Pulse Amplifier Relay is dead, but you shouldn't have one on an '85. :)
4. The wiring between these components is dead - on an '85, I would not be surprised.
Start at the ICU. Unbolt the ICU from the fender and pull it up. Pull the boot off the back of the connector. Connect your DMM to the appropriate pins (it's in Bentley) BUT DO NOT unplug the connector - enter it from the, uh, rear. Have someone turn the engine over and test for voltage (4VDC, IIRC). If you get that, check the tach output signal from the ICU - it's in the Bentley. If you don't get 4VDC (again, IIRC) here you've got a dead ICU. My money is on this component.... Hall Senders rarely die IME (though the wiring does). You can get a replacement from ANY 900T I believe, so there are tons out there. If you do get signal here, you've got a break somewhere between this little bugger and your ECU. Another test point is at the instrument cluster, but this one is hard to get to. You can look in the Bentley for the right pin to test on the cluster - you should be able to access it through the speaker grille.
Let me know how this goes...
-Justin
posted by 64.164.3...
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |