Seatbelt Warning Light And Buzzer

[JerryB]

Gentlemen my o4 Vision is turning on the seat belt warning light and warning buzzer when I hit a bump and all instrument gauges are going dead. I can't find a loose connection and it goes back to normal when I bump the dashboard with my fist. It acts like a loose wire or connection but I can't find the problem so does anyone have a suggestion on how to check this out?? A friend suggested maybe a broken circuit board in the instrument panel so does that sound right??

It only happens when moving and the computer diagnosis at Mack Houston doesn't show anything wrong. Thanks Jerry

[rhasler]

Gentlemen my o4 Vision is turning on the seat belt warning light and warning buzzer when I hit a bump and all instrument gauges are going dead. I can't find a loose connection and it goes back to normal when I bump the dashboard with my fist. It acts like a loose wire or connection but I can't find the problem so does anyone have a suggestion on how to check this out?? A friend suggested maybe a broken circuit board in the instrument panel so does that sound right??

It only happens when moving and the computer diagnosis at Mack Houston doesn't show anything wrong. Thanks Jerry

In my experience the guage cluster is generally at fault, but there is no real way to test it prior to replacing it. You can do a manual guage sweep by doing the following: Depress and hold the Mode button for longer than 2 seconds (with the ignition ON and the engine NOT running) to initiate a self-diagnostic routine. The routine includes positioning all gauges (with the exception of the air pressure gauge) to the 12 o'clock position, activating all indicator lights and LCD segments for 5 seconds and activating an audible alarm for 2.5 seconds.

The seatbelt light is controlled by the circuit board in the guage cluster, so it's activation indicates that the cluster is bad. It's not difficult to replace, requires no programming, only tools needed are #27 and #8 torx drivers. Unfortunately there are no servicable parts inside other than the bulbs.

[JerryB]

In my experience the guage cluster is generally at fault, but there is no real way to test it prior to replacing it. You can do a manual guage sweep by doing the following: Depress and hold the Mode button for longer than 2 seconds (with the ignition ON and the engine NOT running) to initiate a self-diagnostic routine. The routine includes positioning all gauges (with the exception of the air pressure gauge) to the 12 o'clock position, activating all indicator lights and LCD segments for 5 seconds and activating an audible alarm for 2.5 seconds.

The seatbelt light is controlled by the circuit board in the guage cluster, so it's activation indicates that the cluster is bad. It's not difficult to replace, requires no programming, only tools needed are #27 and #8 torx drivers. Unfortunately there are no servicable parts inside other than the bulbs.

Thanks rhasler. Maybe my friend was right then. The company I'm leased to has a few wrecked visions in their bone yard so I can borrow a panel and check it out. thanks again for your help. Jerry.

[rhasler]

Thanks rhasler. Maybe my friend was right then. The company I'm leased to has a few wrecked visions in their bone yard so I can borrow a panel and check it out. thanks again for your help. Jerry.

I did forget to say that the guages (except the speedometer and tach) can be replaced. Also, if you don't have some guages (for instance boost pressure) and you install a cluster that does the guage will not work unless the VECU is reprogrammed to enable that guage.

[JerryB]

I did forget to say that the guages (except the speedometer and tach) can be replaced. Also, if you don't have some guages (for instance boost pressure) and you install a cluster that does the guage will not work unless the VECU is reprogrammed to enable that guage.

Thanks rhasler. I tried the bone yard panel and all is well with it. I didn't want to throw away $350 on a new panel if that wasn't the prob.

[rhasler]

Thanks rhasler. I tried the bone yard panel and all is well with it. I didn't want to throw away $350 on a new panel if that wasn't the prob.

Can't blame you there.

[9speed]

I know this is a little late, but maybe others with the same problem....... See Mack service bulletin SB-732-005. While this is directed for "older trucks" than yours, I have had similar problems with '02/'03 CH613s. In a couple of rare instances, I've been able to fix a ground wire connection at the printed circuit harness plug, but most of them required a a new cluster. Like you were told in an earlier reply, it's an easy fix (swapping out the cluster).I didn't bother to swap the white plastic insulator (that's where you would need the forementioned T-8 Torx) that covers the back of the tach and speedo, and you'll see why when you get there. It took a lot longer to clean the dirt off of the gauge bezels before installing them in the new cluster than anything else. I didn't have to reprogram anything. As soon as I turn the key on after the installation, the correct odometer mileage shows up, and everything worked "as advertised". Good luck.......