Engine - Rolling/Unstable Idle In Neutral With A/C ON
89Ford28AIR CONDITIONING-4.9L-LACK OF A/C DEMAND SIGNAL RESULTS IN ROLLING/UNSTABLE IDLE WHILE IN NEUTRAL
IDLE-4.9L-ROLLING/UNSTABLE IN NEUTRAL WITH A/C ON
Article No. 89-18-8
LIGHT TRUCK: 1989 ECONOLINE
ISSUE: A rolling/unstable idle in neutral with the A/C turned on may be caused by the lack of an A/C demand signal to the EEC processor.
ACTION: Install a circuit between the mode side of the A/C de-ice pressure switch and Pin 43 of the EEC processor. Refer to the following procedure for service details.
1. Remove the battery from the vehicle.
Figure 1:
2. Remove the connector plug from the EEC processor and free the harness as much as possible to gain access, Figure 1.
Figure 2:
3. Remove the connector wire shroud, it snaps off.
4. Snap the cover loose and pull it back over wire harness as far as possible, Figure 2.
Figure 3:
5. Locate the position of Pin 43 in the cover and remove shaded area as shown in Figure 3.
Figure 2:
6. Grasp the retainer/spacer at bolt hole with pliers and remove it, Figure 2.
Figure 3:
7. Insert a terminal (E4LY-14448-B) and a 16 gauge wire into position 43 in the connector. It snaps into place.
8. Push the retainer/spacer back into the connector.
9. Push and snap the cover back onto the connector.
10. Seal around circuit in position 43 with RTV sealer, Figure 3.
Figure 4:
Figure 5:
11. Splice an added circuit into circuit 348 (LG/P) about 2-3 inches from the A/C de-ice pressure switch using a dura-seal butt splice connector (E6FZ-14488-B). See Figures 4 & 5.
12. Tape wrap the new circuit to wire harness 12A581.
13. Reinstall the wire shroud on the connector.
14. Reinstall the EEC connector plug on the processor.
15. Secure the wire harness.
16. Reinstall the battery in the vehicle.
17. Check the vehicle for proper operation.
NOTE: REFER TO THE 1989 ENGINE EMISSIONS DIAGNOSIS MANUAL, VOLUME H FOR IDLE SPEED SETTING SPECIFICATIONS.
PART NUMBER PART NAME CLASS
E4LY-14448-B Terminal C
E6FZ-14488-B Dura Seal Connector BM
D6AZ-19562-BA RTV Silicone Sealer B
OTHER APPLICABLE ARTICLES: None
WARRANTY STATUS: Eligible Under Basic Warranty Coverage
OPERATION DESCRIPTION TIME
891808A Install New Circuit 1.0 Hr.
DEALER CODING
BASIC PART NO. CONDITION CODE
12A581 H7
OASIS CODES: 620100, 620800