and no I don't have the answer. My partner (he got a 90 Q after I got mine) had his mechanic go over it to tell him what is wrong with it. He used to do the work on his Merc. But he is over his head with the Q. When the car came back from the exam, the speedo was backwards. It now sits in the 160 mph position and actually works backwards. And sometimes it works normally. Sometimes the needle shakes. What did this guy do to make it do this? Any ideas?
Modified by SUITE E at 5:05 PM 12/25/2004
TRICK QUESTION
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szh
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Unfortunately, no longer a Nissan or Infiniti, but continuing here at NICO! - Location: San Jose, CA
Re: TRICK QUESTION (SUITE E)
A WAG (Wild a** Guess) : did he plug the speed sensor in backwards? If it is an electronic doohickey, it may be causing high and low voltages to be reversed ...
Z
Z
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Q45tech
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1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Re: TRICK QUESTION (szhosain)
The speed sensor is just a " tone wheel" AC generator that an IC measures the frequency of and translates to a zero to 5 volt signal to feed the speedometer [just a dc voltmeter].
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Meaux
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Re: TRICK QUESTION (Q45tech)
Sounds like something I could do without trying.......and I ain't no mechanic, errr tech. I don't think I'd be taking my car back to him........I can mess things up all by myself...
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szh
- Posts: 15932
- Joined: Tue Jul 23, 2002 12:54 pm
- Car: 2018 Tesla Model 3.
Unfortunately, no longer a Nissan or Infiniti, but continuing here at NICO! - Location: San Jose, CA
Re: TRICK QUESTION (Q45tech)
My dumb question: could ground and high (5V) be reversed at the speedo (or at the output of the IC)? Since the speedo is just a DC voltmeter, this might cause it to have a "reverse" reading when the voltage "drops" negative - assuming that the speedo is otherwise grounded properly.Q45tech wrote:The speed sensor is just a " tone wheel" AC generator that an IC measures the frequency of and translates to a zero to 5 volt signal to feed the speedometer [just a dc voltmeter].
Z
Re: TRICK QUESTION (Meaux)
we would take it back to him, but he has already admitted he doe not know what he did, nor how to fix it.
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Meaux
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Re: TRICK QUESTION (SUITE E)
At least he's honest.
Some guys work on things till they fix em'. :-) and empty your wallet at the same time..... :-)
Some guys work on things till they fix em'. :-) and empty your wallet at the same time..... :-)