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Holley 7'' Digital Dash and 3.5'' Dash read different...

  • Thread starter Thread starter gaslog4
  • Start date Start date Dec 20, 2022

gaslog4

New Member
Aug 15, 2016
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Raleigh NC
Dec 20, 2022
#1
  • Dec 20, 2022
  • #1
Upgraded from the 3.5 handheld to the 7'' Holley Dash to my Terminator X in my 91 Fox Body Mustang...The 7.0'' Dash will not read the data correct from the can connection...I put a splitter in the can connection and hooked back up the 3.5 Handheld to compare readings...The 3.5 reads correct and the 7'' reads incorrect on some readings...Water Temp on the 3.5 reads 155* and on the 7'' will read 103*...Volts will read 14.2V on the 3.5 and the 7'' will read 33.5V...Fuel pressure will read 43 psi on the 3.5 Dash but 0.0 on the 7.0...Got Holly Tech support on the phone and we checked to make sure that the software versions were up to date and correct on both the 7.0 Dash and the Terminator X ECU...After literally an hour of trying different things, he suggested I need to send the 7.0 Dash and my ECU back to them to be checked out....They have a 3-4 week lead time for repairs, and I was not happy about that...Have any of you all had anything like this or suggestions as to what I might can try, before I have to send the Dash and the ECU back to Holley...and Yes he wants both of them...
 

Grn92LX

Fidanza Man!
Founding Member
Jan 14, 2001
6,819
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129
New York
Dec 21, 2022
#2
  • Dec 21, 2022
  • #2
Definitely sounds like a firmware mismatch. Go to Holley's website, click support, terminator x, then find the 7" dash terminator x firmware you need.

Is your ecu on V2 build80?
 
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