Engine belt diagrams 4 ford - Online Auto Repair Engine belt diagrams 4.9l ford. Replacing a drive belt without a diagram is not easy. By request I have posted a picture of the belt routing for this extremely popular Ford V8 engine. Drive belt failures are still one of the leading causes of on the road breakdowns. 1994 F150 4 9 Engine Diagram - Wiring Diagram Schema Answered by a verified ford mechanic. Here is the vacuum diagram 1994 gasoline engines click here. 1994 F150 4 9l Engine Di..