Service engine light and no tach

[GAVERY]

Loaded and ready to go off for a week in the 04 Adventurer and when I started up the service engine light came on steady. The Workhorse book doesn't say much except to check gas cap and put some fuel in if you are low. Went to gas station and on the way I noticed that the tachometer only showed 1000 rpm. This at 55 mph so knew something was wrong. Fueled it and check gas cap but light is still on and now tach reads zero. Tried a few Workhorse dealers but no service departments open on Saturday and can not find a factory number to call. Anyone ever have this problem? Any help will be appreciated-vacation time is going down the drain. Thanks very much.
Glen

["007"]

If your speedometer is OK I would drive it.
One thing you can do is disconnect the chassis battery and see if the display will reset or pull plug on back of display and reset that.
Reseting the plugs in back may clean any dirt or corrosion on pins.
Here is a Actia Service Manual

[dirko]

Hi Ho: What do you get when you hook up an OBDII? Sometimes this can be useful.

[GAVERY]

Thanks 007. Pulled plug on back and have rpm back but still have the service engine light on. Will make some calls in the morning. Thanks again.
Glen

[GAVERY]

Dirko,
Not sure what an OBD II is or where to hook it. Thanks.
Glen

[grumpy14]

NOW PULL OFF CHASSIS BATTERY CABLE LEAVE OFF AT LEAST 60 SECONDS opps sorry i,m yelling and see if that resets light

[GAVERY]

Grumpy,
Been yelled at before-no problem. Unhooked chasis battery for some time and still have the service engine light but the tach is back. Thanks.
Glen

["007"]

Service engine light may take a few starts of engine before it goes out.