Digital readout

Dragon · Jul 17, 2019

Good morning

I replaced my digital readout a couple years ago along with dump valve, and transducer along with new air lines. My readouts have never worked right, volt meter reads 14.4 volts all time and the air pressure readout reads zero most of time but bounces around randomly. now my digits are starting to miss there segments. Has anyone experienced this type of behavior.:xzqxz:

Dragon

rocket1lf · Jul 17, 2019

The only time my readout was funky was when it got wet. It did work correctly after it dried out. Rick

tomg · Jul 17, 2019

I had replaced mine as every time the voltage dropped below 13.8, the air pressure reading would drop anywhere from 10-15 lbs lower. As soon as the voltage went back to 14 or higher the correct air pressure would be indicated. The new gauges provided by TMS did the same thing after about a week so I just learned to live with it. Tomg

trikervet · Jul 17, 2019

I have had zero problems with those gauges. Once they got wet and blanked out, but back to normal when they dried out.

tomg · Jul 17, 2019

trikervet said:
I have had zero problems with those gauges. Once they got wet and blanked out, but back to normal when they dried out.

I hope the good luck stays with you! I've spoken to several over the years with problems with the digital gauges. Tomg

Dragon · Jul 18, 2019

Thanks for replays, like you said live with it, that's what I have been doing but when the display started doing weird things I thought something might be wrong someplace else:Shrug:

Dragon

tomg · Jul 18, 2019

Dragon said:
Thanks for replays, like you said live with it, that's what I have been doing but when the display started doing weird things I thought something might be wrong someplace else:Shrug:

Dragon

I also reversed the wires so up was down and down was up and that corrected mine with fewer bad readings but don't understand why it made the difference. Tomg

trike tech · Jul 30, 2019

Air pressure reading zero is likely a "signal issue" from the transducer (not very common that a readout causes that part).. Missing digits & flickering digits is likely a readout issue. That being said, below is a detailed method of troubleshooting a fluctuating air pressure readout (digital only). If followed to the letter and in the sequence listed it WILL tell you where the "issue" is to help determine what's necessary to correct/fix it.

Adding this part only because I feel it can’t be “overstated” for understanding. The digital readout will show a change in air pressure when riding; the pressure fluctuation is only in the readout itself. The compressor and or dump valve are not actually increasing the air pressure or removing air from the system. The fluctuation is because of suspension travel (as it compresses it reads as an increase in air; as it relaxes it shows a decrease) and is completely normal; however the amount of fluctuation has a great deal to do with road quality, load on the bike in relation to baseline air pressure (which should be set prior to loading bike), etc. On “normal” roads with recommended air pressures a 10psi fluctuation is considered normal and can be expected.

A smaller fluctuation (20 to 50-80ish) it could be caused by either a loose connection at the transducer (thumb screw may have backed off from vibration), signal wire issue, or could possibly be the readout itself and or transducer causing the issue. The loose signal wire at the transducer is the most common cause.

A high fluctuation (100+ psi increases, can read as high as 435) is almost always a ground issue that needs to be corrected (specifically a loss of ground at the transducer).

With either fluctuation the “testing” is the same.

First step is to verify the thumb screw securing the green signal wire (ring terminal) at the transducer is tight. If you can wiggle or rotate the wire it’s loose enough to be an issue. If loose, correct & see if problem is resolved; if not move to next step.

Check metal body of transducer for resistance to ground (transducer body should be fully grounded). If you have a weak ground input, measure ground resistance to aluminum block the transducer is threaded into. Ground issues @ the transducer traditionally result in high pressure fluctuations (200+psi). If you are experiencing a low pressure fluctuation you can skip this step.

If ground is weak at BOTH the transducer AND the aluminum block, simply tie in a new chassis ground & secure via mounting bolt for aluminum block.

If ground is weak at transducer but you have GOOD ground @ the aluminum block, the threading of the transducer into the block is preventing a proper ground (often caused by common thread tape, we recommend a liquid thread sealant).

Recheck ground continuity and verify proper ground for both.

Check continuity on the signal wire from the transducer to where it goes into the back of the digital readout (this wire should have GOOD continuity between the two ends). If wire does not have proper continuity, it’s often easier to simply run a new wire from front to back. If you have proper continuity, no action steps needed to address here.

At this point if you have not found ANY faults or causes for the pressure fluctuation, monitor the resistance to ground at the green signal wire where it connects to the digital readout WHILE operating the air suspension. As you air up and remove the air from the system you should show a steady & repeatable change in resistance to ground on the signal wire. If at any point in the pressure change the resistance becomes erratic and is not ‘reliable” this indicates a bad transducer that is “hanging up” internally. Most common symptom when this is the fault is an air pressure readout that “sticks” at certain psi ranges but works normally above and below the specified range.

If there is no issues present during ANY of the above testing the digital readout itself has an internal fault that is causing the issue and needs to be replaced to correct. If any step of the above testing is skipped or bypassed the accuracy of the final diagnosis will not be accurate & you may not find the source of the issue at hand.