Temperature Issue
Thread Starter
Instructor
Joined: Dec 2004
Posts: 217
Likes: 1
From: Cortez Florida
Temperature Issue
I recently installed a new ZZ 385 crate motor in my 1965 convt. The old motor was worn out but always ran 180 degrees once warmed up indicated by the gauge and verified by my Raytec minitemp. The only part I transferred from the old motor to the new is the temp sender. The new motor runs great and I'm very happy with it....however my temp gauge now reads 200 degrees once warmed up though the Raytec is telling me 180. I DID not change anything else that should have any impact on the sender or the gauge. Where do I start? Any ideas and direction will truly be appreciated. Phil
Team Owner
Joined: Oct 2000
Posts: 38,897
Likes: 1,927
From: Washington Michigan
You probably have a better ground path with the new engine; lower resistance through the sending unit to ground = higher gauge indicated temperature. 
Last edited by JohnZ; Sep 2, 2008 at 11:50 AM.
Thread Starter
Instructor
Joined: Dec 2004
Posts: 217
Likes: 1
From: Cortez Florida
Thread Starter
Instructor
Joined: Dec 2004
Posts: 217
Likes: 1
From: Cortez Florida
Thought you might be interested. I decided to try a new temp sender to see if I might get lucky. Not a chance ......The original sender read +30 degrees over the IR confirmed 180, A new AC Delco #20379 read +50 degrees, A new Sorensen WT203Z (Advance Auto) read +30 degrees and a Wells TU5( Auto Zone) read +50 degrees. For the heck of it I ordered one more from DeWitts and this one is supposed to be calibrated to the gauge. I'll let you know the result. An adjustable resistor may be in my future. Phil
