: 1993 Allante speedometer problem



giants1954
05-12-11, 12:22 PM
Hello Guys---

Have a 93 Allante with analog instruments. Battery went bad during the winter-60 months exact--tried to start---I think low voltage caused a problem with the speedometer--it went from 0-140 MPH and pegged itself and has stayed there.
Replaced the battery--everything seems to work perfect--but the speedo is pegged and does not move--ignition on or off.

Hopeing the wisdom of the group can help.---Ray

D Yaros
05-14-11, 01:50 PM
I am having a little trouble wrapping my head around this one. If it is an analog dash, the speedo should be mechanical, not electrical. I cannot comprehend how changing the battery here would case the needle to peg out at 140 MPH? May sound dumb, but have you tried tapping on the speedometer cluster?

giants1954
05-14-11, 06:50 PM
An electrical pulse sending unit at the tranny sens pulses to the speedo. Yes--I tried tapping on the cluster to no avail. But--we all get lucky once in a while. I decided to do another road test and try the cruise control for confirmation of failure. I didn't expect it to work but nothing ventured? Set up at aprox 40 MPH and voilla--the cruise engaged-but still 155 MPH on the speedo. Decided to accelerate the cruise to see what happens? At about 55 MPH--the speedo suddenly dropped to 55 MPH and has acted normally the rest of the test drive. Did a shut down -and started up-all good! Thanks so much for just offering an idea----Ray

D Yaros
05-21-11, 10:05 AM
Glad you found a solution. Great improvisation/thinking on your part!