Any diagnosis & repair hints for the Q45 speedometer?
Mine has been intermittent ever since I bought the car over a decade ago. Finally it went down for the count. Even at highway speeds, the speedo doesn't budge a bit (it used to waver around about 20mph indicated speed at about 65mph true speed).
The tachometer, and other c0ckpit gauges appear to read correctly.
I have not yet researched the cause and effect; so, even very simple diagnosis suggestions are welcome.
Q45 Speedometer Intermittent (Diagnosis & Repair)
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Q451990
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- Car: 1990 Q45 - 118K, 2022 Toyota 4 Runner, 2004 Frontier M/T - 108K, 2012 Xterra (Mom's), 2023 Rogue (Inlaws)
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I think you can assume that it's the speedometer if you don't notice other problems (like power steering drop-out) at the same time. There's a guy called Used_Part_Hunter on eBay that had several clusters for sale - bought a spare for $14 plus shipping. It was covered in dust, but if you're just stealing parts, it should be OK to clean it gently with a vacuum cleaner and paint brush.
Heath
Heath
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Q45tech
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- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Since the entire cluster would run over $2,000 at a dealership.The tachs sometimes fail the same way and the bulbs burn out so always good to have a complete unit around for spares .
2 models: 90-93 are interchangable as are 94-95 for both years.
Ebay is great bought many new parts there. Especially things that fit in techs pockets. Never see any brand new trannies or driveshafts, or ABS though.
2 models: 90-93 are interchangable as are 94-95 for both years.
Ebay is great bought many new parts there. Especially things that fit in techs pockets. Never see any brand new trannies or driveshafts, or ABS though.
One of the beautys of this forum is being able to learn from the mistakes of others.... Here's a $300 gift for you...
I’ve done this a few times. Replaced speedo with no problem whatsoever… The 2nd time was to replace Trip bulbs…(something I highly recommend you do while you’re at it)….that’s when all hell broke loose… The speedometer can be replaced by removing the cluster and pulling the back off... Be very meticulous with every step you take since there are many parts to contend with and it’s easy to break. Not difficult but very painstaking...$hit, let me not lie…it was difficult for what I went through! Those plugs behind the cluster are a ***** to deal with especially when you have large paws like I do. BIG HINT… the entire steering column can be dropped by loosening the bolts underneath the dash (that’s what they do they do at the dealer)…I didn't consider this prior but it all made sense when the tech was talking to me.
When I last pulled out the cluster to replace the Trip bulbs, I left a plug loose (it didn't "click" in I guess) it ended up costing me near $300 bucks for that little mistake (towing to dealer + labor.. thank God no parts were required). See, I had forgotten a little detail....Not only did I not disconnect the battery, I had the car running with AC on since it was middle of summer at the time (a big no no but after downing a six pack...you get the picture). While putting the cluster back in, the car suddenly shut down. I was able to start it but that was about it… I was so sure that I had shorted something out that I had nary a thought about checking the plugs. I was thinking that I may have fried wires/circuits. The alternator had stopped charging, the AC didn't work, no lights inside the car….and a whole list of other frightening symptoms. Towed the car to the dealer and the tech pushed on one of the plugs behind the cluster to fix. To be perfectly honest, even though I left the dealer massaging my a$$, I was happy to write the check when I found out that nothing was harmed……a very costly mistake but you live and learn.
FYI, the speedo and Odometer are separate units even though they seem to be one appearance-wise. Be careful not to roll the tumblers as that would be considered illegal tampering....if you do, they will not line up perfectly again. Keep dust down to a minimum and blow out with compressed air before assembling. I had to take my whole assembly apart again just to remove foreign matter residing inside my cluster... it annoyed the hell out of me seeing that french fry sitting in front of the tach (joke).... Also, any dust or particles would be a clear indicator of someone having gone inside if I was to sell. Don't use windex on the "glass" since it's really plastic and might be etched by the ammonia. I’m sure if you search you can find the steps for cluster removal…just remember to drop the steering column too. Good luck. Sorry for rambling, thats how things are when you type long posts at work.
I’ve done this a few times. Replaced speedo with no problem whatsoever… The 2nd time was to replace Trip bulbs…(something I highly recommend you do while you’re at it)….that’s when all hell broke loose… The speedometer can be replaced by removing the cluster and pulling the back off... Be very meticulous with every step you take since there are many parts to contend with and it’s easy to break. Not difficult but very painstaking...$hit, let me not lie…it was difficult for what I went through! Those plugs behind the cluster are a ***** to deal with especially when you have large paws like I do. BIG HINT… the entire steering column can be dropped by loosening the bolts underneath the dash (that’s what they do they do at the dealer)…I didn't consider this prior but it all made sense when the tech was talking to me.
When I last pulled out the cluster to replace the Trip bulbs, I left a plug loose (it didn't "click" in I guess) it ended up costing me near $300 bucks for that little mistake (towing to dealer + labor.. thank God no parts were required). See, I had forgotten a little detail....Not only did I not disconnect the battery, I had the car running with AC on since it was middle of summer at the time (a big no no but after downing a six pack...you get the picture). While putting the cluster back in, the car suddenly shut down. I was able to start it but that was about it… I was so sure that I had shorted something out that I had nary a thought about checking the plugs. I was thinking that I may have fried wires/circuits. The alternator had stopped charging, the AC didn't work, no lights inside the car….and a whole list of other frightening symptoms. Towed the car to the dealer and the tech pushed on one of the plugs behind the cluster to fix. To be perfectly honest, even though I left the dealer massaging my a$$, I was happy to write the check when I found out that nothing was harmed……a very costly mistake but you live and learn.
FYI, the speedo and Odometer are separate units even though they seem to be one appearance-wise. Be careful not to roll the tumblers as that would be considered illegal tampering....if you do, they will not line up perfectly again. Keep dust down to a minimum and blow out with compressed air before assembling. I had to take my whole assembly apart again just to remove foreign matter residing inside my cluster... it annoyed the hell out of me seeing that french fry sitting in front of the tach (joke).... Also, any dust or particles would be a clear indicator of someone having gone inside if I was to sell. Don't use windex on the "glass" since it's really plastic and might be etched by the ammonia. I’m sure if you search you can find the steps for cluster removal…just remember to drop the steering column too. Good luck. Sorry for rambling, thats how things are when you type long posts at work.
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slaughtermimms
- Posts: 114
- Joined: Mon Jan 13, 2003 5:30 pm
- Car: '95 Infiniti Q45
'02 Ford F150 - Location: Augusta, GA
I do not have the name of the company, but they are in VA. and for about $ 100 they will fix your to better then new. Sorry I do not have more info. If you search the web you might get lucky, I did. I found out that the little motor dies. They bring it back to life by rebuild the motor.
Good Luck!!!!!!!!!!! :thinker
Good Luck!!!!!!!!!!! :thinker
Sorry for not replying sooner; I was on a busy cross-country trip sans computer.
What I don't know is how that speedometer works. What spins where? I can't even contemplate fixing or repairing it until I know how it works.
Do you know where the sensor is that picks up the spinning?
Do you know how the Q45 speedometer works?
What I don't know is how that speedometer works. What spins where? I can't even contemplate fixing or repairing it until I know how it works.
Do you know where the sensor is that picks up the spinning?
- Is the speed sensor in the transmission?
- Is the speed sensor on the rear axle?
- Is the speed sensor electronic or mechanical?
- How does it transmit the speed to the speedometer (electrical via wire? mechanical via cable?)
Do you know how the Q45 speedometer works?
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Q45tech
- Moderator
- Posts: 14296
- Joined: Tue Apr 30, 2002 3:19 am
- Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl
Simple the speed sensor on the transmission shaft creates a variable frequency which is converted [by an IC] to a zero to 5.0 volt signal which drives the speedometer display gauge [just a voltmeter]. The same zero to 5.0 volt signal is isolated and feeds 4 other systems [ABS, AT, ECU, PS, Cruise] so if these systems are working the meter is just bad [sticky-worn pivot bearings].
Impossible to fix meter and maintain calibration.......just easier and cheaper to get a used display and swap...........the IC and calibration is on the back of meter so the replacement takes care of everything...........DUH. Same with swap whole dash display except you have to deal with odometer.
Unfortunately you cannot operate car without speedometer assembly [send away for repairs] as the lack of speed signals will make the car un drivable [no shifts, no power steering, ecu throwing up all over the place, ABS errors etc.
Impossible to fix meter and maintain calibration.......just easier and cheaper to get a used display and swap...........the IC and calibration is on the back of meter so the replacement takes care of everything...........DUH. Same with swap whole dash display except you have to deal with odometer.
Unfortunately you cannot operate car without speedometer assembly [send away for repairs] as the lack of speed signals will make the car un drivable [no shifts, no power steering, ecu throwing up all over the place, ABS errors etc.
OK. Sounds well considered. The car runs fine so the speed sensor in the transmission must be good. The wires are presumed good for the same reason. Therefore, the gauge is presumed bad. Or the connection to the gauge.
Fixing the gauge is one possibility; but that seems to be frowned upon (based on the tone of the responses). Replacing with used parts seems to be the general consensus.
Either way, it looks like I'll need to REMOVE the Q45 instrument cluster. I found these links:- NICO Forums > Online Mechanic > Infiniti Online Mechanic > q45 Instrument Cluster- NICO Forums > Nico General > Infiniti General > Help with removing Q's Dash- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 93 Q45 transmission/speedometer weirdness- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 96 Q45 100K Speedometer Replacement- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 1996 Q45 Speed Sensor-NICO Forums > Nico General > Infiniti General > Odometer and Trip Meter- Infiniti Online Mechanic > Trip Meter Fading Out (90 Q45)- NICO Forums > Online Mechanic > Infiniti Online Mechanic > Trip Meter Fading Out (I30)- NICO Forums > Nico General > Infiniti General > HELP!! with bulb replacement
The best two of this list were probably:NICO Forums > Online Mechanic > Infiniti Online Mechanic > q45 Instrument Clusterand NICO Forums > Nissan/Infiniti Articles > Infiniti Articles > Removing Dash on 90-93 Q45
In the 1990 FSM, page BF-20 (Instrument Panel) shows instrument panel removal instructions & an exploded diagram. EL-49 (Meter and Gauges) shows a closeup of the Combination Meter & a simplified wiring diagram. EL-52 (Meter and Gauges) shows a flow diagram for the speed sensor signal test.
Since the car apparently becomes inoperative w/o the speedometer, I may not tackle this for a while. Before I do, did I miss any key references to guide me in the speedo removal, dissasembly, possible repair or replacement, and dash instrument cluster reassembly?
Fixing the gauge is one possibility; but that seems to be frowned upon (based on the tone of the responses). Replacing with used parts seems to be the general consensus.
Either way, it looks like I'll need to REMOVE the Q45 instrument cluster. I found these links:- NICO Forums > Online Mechanic > Infiniti Online Mechanic > q45 Instrument Cluster- NICO Forums > Nico General > Infiniti General > Help with removing Q's Dash- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 93 Q45 transmission/speedometer weirdness- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 96 Q45 100K Speedometer Replacement- NICO Forums > Online Mechanic > Infiniti Online Mechanic > 1996 Q45 Speed Sensor-NICO Forums > Nico General > Infiniti General > Odometer and Trip Meter- Infiniti Online Mechanic > Trip Meter Fading Out (90 Q45)- NICO Forums > Online Mechanic > Infiniti Online Mechanic > Trip Meter Fading Out (I30)- NICO Forums > Nico General > Infiniti General > HELP!! with bulb replacement
The best two of this list were probably:NICO Forums > Online Mechanic > Infiniti Online Mechanic > q45 Instrument Clusterand NICO Forums > Nissan/Infiniti Articles > Infiniti Articles > Removing Dash on 90-93 Q45
In the 1990 FSM, page BF-20 (Instrument Panel) shows instrument panel removal instructions & an exploded diagram. EL-49 (Meter and Gauges) shows a closeup of the Combination Meter & a simplified wiring diagram. EL-52 (Meter and Gauges) shows a flow diagram for the speed sensor signal test.
Since the car apparently becomes inoperative w/o the speedometer, I may not tackle this for a while. Before I do, did I miss any key references to guide me in the speedo removal, dissasembly, possible repair or replacement, and dash instrument cluster reassembly?