Questions and Answers

Ram Cruise Control Q. Hello, My problem is my cruise control. It was working and then it just started to act funny. I try to set the speed and it does not set. When I push the resume/accel button, the speed will increase. When I use the set/coast button it acts like it sets but then the speed will drop.

It will drop about five miles then "sets" and then starts to drop. It will drop slowly and about 10 to 15 miles under the set speed, it will try to return to the set speed but its too slow to return. The night before this started, the master cylinder was in need of brake fluid so I added some. I don't think that had anything to do with that but I thought you should know.

1996 Dodge Ram 1500
318 V-8
Automatic Transmission
77,000
Fuel Injection

Thanks,
Dan

A. You're right Dan, adding brake fluid would have nothing to do with the cruise control.

Chrysler put out this informational bulletin out and I thought I would include it here for your information. I don't think it's the cause of your problem.

If the vehicle operator **repeatedly** presses and releases the SET button with their foot off of the accelerator (a "lift foot set" to begin speed control operation), the vehicle may accelerate and exceed the desired set speed by up to 5 MPH (8 km/h) and then decelerate to less than the desired set speed before finally achieving the desired set speed.

The speed control has an adaptive strategy (ability to learn) that compensates for vehicle-to-vehicle variations in speed control cable lengths. When the speed control is set with the vehicle operators foot off of the accelerator pedal, the speed control "thinks" there is excessive speed control cable slack and adapts (learns). If "lift foot sets" are continually used, the speed control overshoot/undershoot condition will develop.

To "unlearn" the overshoot/undershoot condition, the vehicle operator has to press and release the SET button while maintaining the desired set speed with the accelerator pedal (not decelerating or accelerating), and then turn the speed control switch to the OFF position **(or press the CANCEL button, if equipped) after the speed control has been engaged for 10 seconds or longer.** This procedure must be performed approximately 10-15 times to completely unlearn the overshoot/undershoot condition.

However, What I do think is the cause of your problem is the vacuum line at the cruise control servo. The problem results from the vacuum line that is loose, leaking or deteriorated due to battery acid leaking on it. From TSB number 08-22-97 Rev. A dated Jul. 11, 1997.

MODELS:
1996 - 1997 (BR) Ram Truck

SYMPTOM/CONDITION:
Inoperative Speed Control due to a vacuum supply hose that is loose, leaking or deteriorated.

DIAGNOSIS:
Perform the speed control diagnosis as outlined in the 1997 Ram Truck Service Manual (Publication No. 81-370-7108), page 8H-2. If the diagnosis determines that the speed control is inoperative because of a loose, deteriorated, or leaking vacuum supply hose at the speed control servo **due to battery acid dripping on the speed control vacuum hose**, perform the following Repair Procedure.

PARTS REQUIRED:

1	05003576AA	Gasket, Battery Temperature Sensor
AR (1)	52078320	Vacuum Hose, 3.9L/5.2L/5.9L Gas Engine Speed Control
AR (1)	52078323	Vacuum Hose, 8.0L Gas Engine And 5.9L Diesel Engine Speed Control
AR (1)	04713921	Battery, 600 CCA
AR (1)	04713923	Battery, 810 CCA

REPAIR PROCEDURE:
This bulletin involves installing a gasket between the battery tray and the Battery Temperature Sensor (BTS) to prevent battery acid from dripping onto the speed control servo vacuum hose and replacing the battery.

1. Record the radio station presets.
2. Disconnect and isolate the battery negative cable. If the vehicle is equipped with the 5.9L Cummins diesel engine, disconnect and isolate both battery negative cables.
3. Disconnect the battery positive cable.
4. Remove the battery hold down (Figure 1) and remove the battery from the vehicle.
5. Detach the BTS pigtail connector with the plastic fastener (Christmas tree) clip from the battery tray.

   NOTE: The washer reservoir must be removed on 8.0l v10 and 5.9l cummins diesel engines to gain access to the speed control servo. Refer to the 1997 ram truck service manual (publication no. 81-370-7108), page 8k-11 for information regarding removal and installation of the reservoir.

6. Disconnect sensor pigtail harness from the engine wire harness.
7. Using a sharp pick or screwdriver, remove the plastic fastener (Christmas tree) clip from the pigtail connector.
8. Remove the BTS from the battery tray.
9. Remove the metal washer from the BTS and discard the washer.
10. Clean the area around the BTS attachment hole. Then, remove the paper protector from the adhesive of the BTS foam gasket, p/n 05003576AA, and install the gasket onto the battery tray, placing the adhesive side of the gasket on the battery tray.
11. Feed the sensor's pigtail harness through the mounting hole in the top of the battery tray and press the sensor until it snaps into place.
12. Install the plastic fastener (Christmas tree) clip onto the pigtail harness.
13. Connect the pigtail harness and attach the plastic fastener (Christmas tree) onto the battery tray.
14. Disconnect the speed control vacuum hose from the fitting at the engine.
15. Pull the speed control vacuum hose out of the mesh sheathing.

    NOTE: It may be necessary to remove the rubber nipple from the hose to be able to slide the hose through the mesh sheathing.

16. Remove the speed control vacuum hose from the speed control servo.
17. Install the new speed control servo vacuum hose (see Parts Required section) onto the speed control servo.
18. Slide the new speed control vacuum hose through the mesh sheathing and attach the nipple onto the fitting at the engine.
19. Position the new battery (Replace 600 CCA batteries with p/n **0471 3921** and **upgrade the 750 CCA batteries to a 810 CCA battery, p/n 04713923**) in the tray. Ensure that the positive and negative terminal posts are positioned correctly. The cable terminal clamps must reach the correct battery post without stretching the cables.
20. Loosely install the battery hold down hardware. Ensure that the battery base is correctly positioned in the tray, then tighten the hold down bolts to **4.2 Nm (35 in. lbs.)** of torque.
21. Install and tighten the battery positive cable terminal clamp. Then install and tighten the battery negative terminal clamp. If the vehicle is equipped with a 5.9L Cummins diesel engine, install both battery negative cables. Tighten the cable terminal clamp bolts to 8.5 Nm (75 in. lbs.) of torque.
22. Set the radio frequencies to the stations recorded in step one and reset the clock.

CAUTION: Be certain that the battery cables are connected to the correct battery terminals. Reverse polarity may damage electrical components.

Additional Information provided courtesy of ALLDATA