Speedometer issues challenger '97

[OhNoItsMe]

Hi!

I'm new here and did some browsing but havent found an answer to my problem:banghead: I bought a '97 challenger about a month ago and had to have the engine rebuilt a complete rebuild and i've made my peace with that:svengo:

But i do have an issue with my speedometer that tests fine on the trailer but refuses to cooperate on the water.

I'm wondering if the placement of the speed captor is a possible issue as it sits on the back end of the ride plate or idk

Any ideas are welcome as i'm all out of them!

Ty!

 

[Waterluvr]

So, you press the starter button to power up the gauge and then go back and spin the wheel on the speed sensor and your getting a reading?

The leading edges on the sensor wheel wear over time and so does the bushing and pin it rides on. You can replace just the wheel and pin to get it back to turning the required rpms that function the gauge. It's just a simple hall effect device with magnets in the paddles that signal every time they pass by the housing. If it works when you spin it up manually that's probably your issue. When you compare the leading contact edges of your old sensor wheel to a new one you'll see it, just be aware of the orientation of the ears as they are designed to only rotate one way.

It's entirely possible someone messed with it and put it on backwards to, that will still read but not accurately.

Also, cavitation from the jet pump area can interrupt a steady smooth flow of water but should be noticeable when it happens in performance.

 

[OhNoItsMe]

Ty i'll look into that and swap out the wheel and pin

Will lyk how it turns out

 

[Waterluvr]

Ty i'll look into that and swap out the wheel and pin

Will lyk how it turns out

Before you order any parts post of pic or two of what's on your boat let's make sure you have the right housing and the wheel is oriented correctly.

 

[OhNoItsMe]

Ok sounds good will get to that tomorrow or the day after as i am now in the process of replacing the bottom half of my front storage compartment atm i took a chance and ordered the one off the '97 speedster as it looked and infact is the same (only yellow) even found a hardwear store that had a 5.5mm nut driver on hand :thumbsup:

 

[OhNoItsMe]

Here's what my sensor wheel looks like

 

[Waterluvr]

That wheel looks brand new, I would reference and perform the resistance test procedure for that in the manual before doing anything else, you can test it from the plug right inside the transom.

 

[OhNoItsMe]

Well as the speedo works on land but not on water i'm thing i will just save myself some trouble and swap it out and get a gps speedo instead along with a clock and possibly a tach(so they all match)

Thanks again you've been a tremendous help!:cheers:

 

[Waterluvr]

The factory gauge seems to work pretty well when I compared it to my hand help gps, you could have some gunk or a loose pin in the plug that's just messing with the gauge as the whole thing is based on voltage variations in the circuit when the wheel magnets pass the sensor to display a correct reading. Take it loose and and clean the connector and use some dielectric grease on the plug in's.

The voltage test procedure is in the manual, if you don't have the shop manual to reference you really should get one. I can look the test procedure up for you and quote it this time if it helps you.

On Edit: Test procedure for anyone reading the thread with a similar issue

Speed Sensor Verification
The speedometer gives a reading through a
speed sensor. Speed sensor is installed on ride
shoe. It works with the water flow which turns a
magnetic paddle wheel that triggers on electronic
pick-up that in turn sends a speed signal to the
speedometer.
To verify speed sensor, use a voltmeter as
follows:
– From inside of bilge, find connector of speed
sensor.
– Lift end cover of connector and pull out seals as
shown.

– Connect the probes of a digital voltmeter to the
wires inside connector.
– WITHOUT the safety lanyard on its post, press
the start/stop button (any on twin-engine
models) to energize the circuit.
– Ask someone to slowly turn the «paddle wheel
while you watch the voltmeter. You should read
a voltage variation with the voltmeter.
NOTE: You have 33 seconds to take the reading.
Otherwise, you will have to press the start/stop
button again.
If there is no voltage at all, ensure you were within
the 33 seconds supply mode. If so, refer to section
07-06 MPEM to perform further testings.
If there is a voltage but no variation, the speed
sensor is defective and requires replacement.
Properly reinstall seals and close end cover of
connector.

 

[OhNoItsMe]

I'm waiting on my shop manual atm but if u dont mind looking up the test procedure for my speedo that would be awesome, but no need to go out of your way

Ty!

 

[Waterluvr]

I'm waiting on my shop manual atm but if u dont mind looking up the test procedure for my speedo that would be awesome, but no need to go out of your way

Ty!

Your welcome, since you know the gauge works on land it really should be an easy fix on the wiring/sensor side. I just edited my previous post to include the manual procedure for you. There's probably some resistance at the connector plug messing with the voltage, clean it well and test it bet you'll find the problem right there.

 

[OhNoItsMe]

Much appreciated ty!