Tahoe Q7 Guage Issues

[q7myfirstboat]

My first boat JOY!!!

I always find the best forum for whatever I am working on, and this seems to be the spot.

Questions:

Gauges are sporadic along with the radio. Assuming wiring issues somewhere. I'd like to take off dash and start tracing wires. So, how to I get off dash? Basically the steering wheel connection is my concern. (common sense approach, or is there anything to worry about?)

What's the small cylinder type plastic that is about 1" tall next to the bilge pump? There appears to be a wire that looks like a coaxial cable that is cut in half, half way up the boat.

Before anyone ask... yes I test drove and the intermittent stuff was there, but I took the risk. 9k for a 2001 Q7 with a trailer seemed to be a pretty good deal. New upholstery a few years ago.

 

[Silvertip]

If all gauges are intermittent and ALL come back to life at the same time there is but ONE wiring issue. Either the string of gauges is losing +12 volts supply voltage or they are losing the ground connection. Consider that the +12V and ground connection on each gauge are simply jumpered, daisy chain style from the gauge next to it in the string. So start at the gauge closest to the ignition switch which is where power for the gauges comes from. With the key ON (engine not running) check for voltage at that connection. Since ground may be at fault, place the ground lead from your meter on a "known" good ground other than the one on the gauge. String a wire from the negative terminal of the battery for this is the best connection. Now wiggle the wires and see if the gauges come to life and cut off as you are wiggling. If so you found the source. If this has no effect, wiggle the ground connection from the first gauge in the string. My bet it is not the +12 volt connection but rather the ground connection. If there is an in-line connector between the gauges and the boat harness, then disconnect and reconnect that connector several times. Very often all that needs to happen is the contacts be burnished a little and connections are restored. Chances are you don't need to pull the instrument panel. If there is access under the console you may be able to do the testing without pulling the entire panel.

 

[q7myfirstboat]

Awesome, what I was starting to think the more I dug around underneath the dash. I will do that first.

Gauges as follow:

voltage not working at all
temp not working at all
rpm jumpy
mph works (cleaned sensor)
oil pressure on/off with working
trim on/off with working
Gas on/off with working

radio went off while messing around today and the more I fiddled, it came back on.

as soon as I turn on nav lights, gas gauge pegs out

It's just a absolute pain to work under there.

I will follow up

 

[q7myfirstboat]

What do you reckon this is?

 

[mjf55]

Looks to me to be a depth finder transducer that shoots thru the hull. The wire looks to be a coax wire. But I could be very wrong here.

 

[q7myfirstboat]

Looks to me to be a depth finder transducer that shoots thru the hull. The wire looks to be a coax wire. But I could be very wrong here.

That wire goes to it, but cannot trace down after where it broke....half way down the boat

 

[NicoPags]

Possibility that it's an old antenna wire

 

[q7myfirstboat]

Possibility that it's an old antenna wire

Agreed,but seems weird that it's connected to that plastic piece below the motor. Google not h we helping lol