Ram Diesel Manifold Heater Repair

Manifold Heater Removal / Replacement - 12 Valve Engines 1994 - 1998

12 Valve Intake Heater The intake manifold air heater assembly (with internal heating elements) is located between the upper and lower portions of the intake manifold If the heating coils (elements) within the assembly have failed, the entire heater assembly must be replaced.

(1) Disconnect both negative battery cables at both batteries.
(2) Remove the engine oil dipstick tube mounting bracket bolt at the side of the intake manifold
(3) Remove the two cable nuts and remove cables at the air heater electrical studs.
(4) Remove the five bolts retaining the upper half of the intake manifold to the lower half of
     the intake manifold.
(5) Position the intake manifold and manifold connecting tube to the side.
(6) Remove the air heater from the intake manifold.

(7) Clean the mating surfaces of the air heater and intake manifold.
(8) Install a new lower and upper gasket to the air heater.
(9) Position the air heater to the intake manifold.
(10) Install and tighten five bolts to the intake manifold. Tighten to 18 ft. lbs. (24 N•m) torque.
       (The ground cable for the air heater is connected to one of the intake manifold bolts).
(11) Connect the two cables to the air heater.

Manifold Heater Removal / Replacement - 24 Valve Engines 1998 - 2002
The 2 intake manifold air heater elements are attached to a metal block located at the
top of the intake manifold (See Ram Cummins Intake Manifold Heater Parts). If either
of the heater elements is bad, the entire block/element assembly must be replaced.

(1) Disconnect the heater relay feed from the driver's side battery. (2) Disconnect clamp from rubber hose at air intake housing. (3) Disconnect rubber hose at air intake housing. (4) Remove engine oil dipstick tube mounting bolt
(5) Disconnect heater electrical cables at cable mounting studs
(6) Disconnect ground cable bolt and ground cable from housing.
(7) Remove 4 housing bolts (8) Remove air intake housing from top of heater elements. (9) Remove heater element assembly from intake manifold. (10) Clean old gasket material from air intake housing and intake manifold. (11) Clean old gasket material from both ends of heater block
(1) Using 2 new gaskets, replace element and air housing on intake manifold. (2) Position ground cable to air housing. (3) Install 4 housing bolts and tighten to 18 ft. lbs. (24 N·m). (4) Connect heater cables at cable mounting studs Do not allow the cable eyelets to contact any other       metal source other than the cable nuts/studs. (5) Install engine oil dipstick tube and mounting bolt. (6) Connect rubber hose to air intake housing. (7) Connect clamp to rubber hose at air intake housing. (8) Connect the heater relay feed from the driver's side battery.

Manifold Heater Relay Removal / Replacement - All Engines 1994 - 2002

1994 - 2002 Ram Manifold Heater Relay Parts / Location The 2 intake manifold air heater relays are located in the engine compartment, attached by a single bracket to the left inner fender below the driver's side battery. 1 - Battery & Tray - Driver's side 2 - Relay Mounting Molts (3) 3 - Relay Control Wires (4: 2 From ground and 2 from ECM) 4 - Intake Manifold Heater Relays (2 on a single assembly) 5 - Rubber Wire & Terminal Insulators (4) 6 - Feed Cables From Battery Terminal (+12V)

The mounting bracket and both relays are replaced as an assembly.

(1) Service Manual says: "Disconnect both negative battery cables at both batteries." Note: It's easier to just disconnect the relay power feed wires from the driver's side positive battery terminal. (1/2" wrench)

(2) Find the Manifold Heater Relay located on the fender well below the driver's side battery.

(3) Lift four rubber shields from all 4 power cables and remove the four nuts at cable connectors. (1/2" wrench or socket) (4) Disconnect four relay trigger wires at both relays. Note position of wiring before removing. On my 2001, the wire toward the front of the truck was black, the next was Orange w/stripe, the next relay had the black wire in front and then the Yellow w/strip toward the rear of the truck.

  (5) Remove three relay mounting bracket bolts and remove relay assembly. (3/8" wrench or deepwell socket)

(6) Install the relay assembly to the inner fender. Tighten the mounting bolts to 40 in. lbs. (4.5 N•m) torque.

(7) Connect the eight electrical connectors to the relays.

(8) Connect battery cables to both batteries or connect the relay feed to the drivers side battery terminal.

(9) Don't forget to test everything - occasionally you will get a new bad part.

Last edit to this page: March 7, 2008