swamp rat
+1y
Maintenance Reminder Lights
All gasoline engines, starting in 1985 incorporate a dashboard light to remind the owner of necessary maintenance intervals. Reading either "Check EGR" (1985-87) or "Maintenance Req'd" (1988-93), these lights are controlled by the elapsed mileage on the odometer. The light will illuminate first at 50,000 miles (80,000km) and then at 100,000 miles (160,000 km). From 1989, vehicles will energize the light at 80,000 miles (128,000 km) and 120,000 miles (192,000 KM) as well. The light is simply a reminder that system maintenance and inspection is due at these intervals; it is not a warning light in the usual sense.
Resetting
When the light comes on, resist the temptation to simply turn it off. Leave it on until you have the time to perform at least the basic maintenance. Chances are that your vehicle is running pretty well at 50,000 miles. A good tune up with fresh filters will keep it that way. Check the vacuum hoses for cracks and damage. Check the EGR valve using the procedure outlined in this section. If this maintenance isn't possible, at least take the vehicle to a dealer or service station capable of running it on an exhaust analyzer. The content of the exhaust gas can tell you quite a bit about how efficiently the engine is burning fuel.
Once the needed maintenance has been performed, the reminder light may be turned off (which resets it for the next interval) by moving a small switch. On 1985-86 models, the switch is located on the back of the instrument cluster at the top. Reaching it behind the dashboard can require contortions and creative language, but it can be done without removing the instrument cluster. On 1987-93 models, the switch is on the front of the instrument cluster, at the bottom right; the clear plastic window over the cluster must be removed to gain access. Carefully remove the 4 screws and the lens, reset the switch and reinstall the lens.
Dodge recommends that after the 100,000 mile (160,000 km), and on the 1989 and later models, 120,000 miles (192,000 km), service is performed, the light bulb be removed from the indicator. This does not relieve the owner from performing needed maintenance; it just turns the light off permanently. Removing the bulb or disabling the system befor the specified mileage is a violation of the Federal Automobile Emissions Act.
End excerpts from Chilton Ram 50/ D50/ Arrow 1979-93 Repair Manual #20800
FWIW.. My somewhat new to me 1989 Dodge Ram 50 4X4 Sport recently rolled past the 80,000 mile interval, sure enough the "Maintenance Req'd" lamp came on. At first, I thought it was a "trouble light", and gave everything a thorough inspection, finding nothing obvious wrong, I took it to the dealership who said it was due to a a faulty O2 sensor. After replacing the O2 sensor myself, the Maintenance Req'd lamp remained on. Finding nothing else that might explain the light and the truck running OK, I concluding it was an idiot light but it still bugged the pooh out of me. You'd think the dealership would have mentioned the light needed to be reset in order to extinguish it but NO. It was only after buying a Chiltons manual for my Ram 50 that I became aware of and how to reset the annoying light.
Anyhow, I found that I didn't need to remove the clear lens or the instrument cluster trim piece. Just had to remove the toggle switch (blank panel) on the lower right hand side of the instrument cluster trim piece and through that small opening, I could reach the small switch with just an extended index finger.. Go figure... ~LOL~