Paging Tony@AirRideTech

[N2TRUX]

Tony-
I'm having trouble with the pressure gauge on my 77. When I start my truck it comes on and reads correctly. After a short period the digits fade out. I have checked the ground wire, and made sure it was making a solid connection. I also checked the +12v source and it keeps constant voltage even after the display fades out. What the heck is going on?

Oh, btw it's one of these-

[Tony@AirRideTech]

that is strange....... It sounds like the gauge is bad or like you are loosing continuity somewhere. Do you have your "illumination" wire hooked up? I might try disonnecting that if you do and see what happens.

[XXL]

Originally Posted by N2TRUX

Tony-
I'm having trouble with the pressure gauge on my 77. When I start my truck it comes on and reads correctly. After a short period the digits fade out. I have checked the ground wire, and made sure it was making a solid connection. I also checked the +12v source and it keeps constant voltage even after the display fades out. What the heck is going on?

Oh, btw it's one of these-

Where are you getting your illumination juice and ground? A few of the wires under the dash show +12v until you hit the lights, then they go to ground (they're not actually +12, but a test light will provide enough continuity to draw current through the circuit from the other side). On your Chebby, you should be doing a gray or brown wire in the headlight switch for illumination.

[N2TRUX]

Tell me what colors wires go where and I can give an answer. I know Roger gave the installation guide back to me, but I can't seem to find it. I traced the harness coming from the gauge. Four wires go south and I will assume they go to the sensors. I have a black wire going to ground, and a red wire going to a fuse terminal that is keyed hot. Is there a third "illumination" wire? If so, what color is it. That could be my problem.

BTW- As a point of reference the gauge has worked fine every since it was installed. This just started happening after I picked it up from the motor install.

[SCOTI]

Originally Posted by N2TRUX

.....BTW- As a point of reference the gauge has worked fine every since it was installed. This just started happening after I picked it up from the motor install.

This is what makes me think it's not the wiring unless something has come loose under the dash. Knowing Rogers work as I do, that's unlikely.... but anything is possible.

[XXL]

Originally Posted by N2TRUX

Tell me what colors wires go where and I can give an answer. I know Roger gave the installation guide back to me, but I can't seem to find it. I traced the harness coming from the gauge. Four wires go south and I will assume they go to the sensors. I have a black wire going to ground, and a red wire going to a fuse terminal that is keyed hot. Is there a third "illumination" wire? If so, what color is it. That could be my problem.

Fused red goes to the +12v illumination wire from the light switch (or keyed hot if you want it lit any time the key is on). Black is obviously ground. However, as SCOTI mentions, it doesn't sound like a wiring problem since it used to work. Anyone know if those gauges use vacuum fluorescent lighting... it sounds like that circuit is going bad if it lights up, then after a while, peters out. If the lighting is LED or OLED, those usually work or don't work... no middle ground.

[N2TRUX]

Originally Posted by SCOTI

This is what makes me think it's not the wiring unless something has come loose under the dash. Knowing Rogers work as I do, that's unlikely.... but anything is possible.

Scoti- It's possible that something got pulled loose during the install. The first time it happened is when I loaded it on the trailer to bring it home from Stoked Out.

I did just discover a yellow wire that looks like it was connected (end is stripped) and now it's not. I did not have time to trace it back and see if it was coming from the guage harness.

XXL- I assume it's vacuum fluorescent lighting as it is not LED.

[Tony@AirRideTech]

It is VFD... they were built for us by Dakota Digital. Give someone a call up at Dakota and see what they have to say.... the blue wire is for your illumination dimmer. Unhook that one if it is not already done and see what it does.

[XXL]

Originally Posted by XXL

Fused red goes to the +12v illumination wire from the light switch...

Whoops... different unit that I was thinking. I guess I should look at the back of mine before throwing out color codes.