Schematics — Ford Bronco 1987-1991

Technical Reference

Member-uploaded diagrams & documents for this generation. AI-classified; community-verified where badged.

Schematics

• Ford 5.0 Fox Mustang Short Belt Routing Diagram - 84.5" & 70.5" vs Stock
  This document is a screenshot of a forum post showing a serpentine belt routing reference diagram for the Ford 5.0L (302) V8 engine as used in Fox-body Mustangs. Three routing diagrams are shown: an 84.5-inch short…
• Ford Thermactor Air Bypass Valve Cutaway Diagram - Port Identification
  This document is a labeled cross-section (cutaway) line drawing of an air bypass valve, part of the Thermactor secondary air injection (emissions) system. The illustration shows the internal construction of the valve…
• Ford Vacuum Check Valve Direction Diagram - Airflow & Black Vacuum Side
  This document is Figure 125, titled 'Vacuum Check Valve,' from an automotive reference manual. It is a line-drawing schematic showing three different styles of vacuum check valves used in engine vacuum/emissions…
• Ford Thermactor Air Diverter Valve Diagram - Inlet & Outlet Port Identification
  This document is a simple line drawing (schematic illustration) of an automotive air diverter valve, showing the component's external shape and identifying its three hose connection ports. The valve is drawn as a…
• Ford Idle Air Control (IAC) Valve Diagram - Cutaway Schematic & Airflow
  This document is a labeled schematic of a Ford Idle Air Control (IAC) valve. On the left is a three-quarter perspective illustration of the complete valve assembly, showing its electrical connector, solenoid body, and…
• Ford Idle Air Bypass (IAB) Solenoid Cutaway Diagram - Plunger, Spring, Airflow
  This document is a labeled cutaway schematic illustration of an idle air bypass (IAB) solenoid valve, as used on Ford fuel-injected engines to control idle speed. The diagram shows the internal construction of the…
• Ford Idle Air Control (ISC-BPA) Solenoid Cutaway Schematic - Bronco IAC Valve
  This document is a schematic illustration of a Ford idle air control style solenoid valve, shown in two views. The upper portion is an external color rendering of the complete solenoid valve assembly, including its…
• Ford TPS Throttle Position Sensor Wiring Diagram - VREF, TP SIG, SIG RTN Colors
  This document is a color schematic diagram of a Throttle Position Sensor (TPS), showing its internal construction and wiring connections. The illustration depicts the sensor as a circular component with two labeled…
• Integral Gear Power Steering Fluid Flow Diagram - Ford Bronco Gear Box Schematic
  This schematic, titled "Integral Gear Power Steering Function," illustrates the hydraulic fluid flow inside an integral power steering gear box under three operating conditions: Straight, Right Turn, and Left Turn…
• Ford Thermactor Air Control Valve & Check Valves Diagram - Rear Engine View
  This document is a black-and-white line-art schematic (with the key components highlighted in red) showing the Thermactor secondary air injection plumbing at the rear of a Ford V8 engine, as viewed from behind (labeled…
• Ford 5.0L Thermactor Secondary Air System Diagram - Air Pump & Check Valves
  This document is a two-part factory-style schematic of the Thermactor secondary air injection system on a Ford 5.0L V8 engine. The left illustration shows the components installed on the engine as viewed toward the…
• 1990 Ford Bronco 5.8L Thermactor Air Pump & Bypass Valve Diagram (A9394-B)
  This document is a labeled line-art schematic of the Thermactor (secondary air injection) system components on a Ford EFI V8 engine, shown from the front-left perspective with an arrow indicating 'FRONT OF ENGINE.' The…
• 1990 Ford Bronco 5.0L Thermactor Air Pump, Bypass Valve & Silencer Diagram
  This document is a line-art schematic (illustration number A12775-A) showing the front view of an engine's secondary air injection (Thermactor) system components. An arrow at the upper left indicates the direction of…
• 1990 Ford Bronco 4.9L Thermactor Air Pump & Check Valve Location Diagram
  This document is a Ford factory-style schematic illustration (figure ID A13526-A) showing the secondary air injection (Thermactor) system components on an inline six-cylinder EFI engine, consistent with the 4.9L engine…
• 1990 Ford Bronco 4.9L Thermactor Air Pump, Bypass & Check Valve Diagram
  This document is a factory-style line-art schematic of the secondary air injection (Thermactor) system components on an inline six-cylinder Ford engine, consistent with the uploader's claim of a 1990 Ford Bronco 4.9L…
• Ford 5.0L Thermactor Air Pump & Check Valve Hose Routing Diagram (A7746-E)
  This document is a two-part line-art schematic of the Thermactor secondary air injection (smog pump) system on a Ford V8 engine, uploaded as "1990 Mustang 5.0L Emissions.jpg" to a 1990 Ford Bronco gallery. The left…
• Ford Thermactor Air Control & Check Valve Location Diagram - Rear Engine View
  This document is a black-and-white line-art schematic drawing showing the rear view of an engine's Thermactor (secondary air injection) plumbing. Three components are called out with arrows: an AIR CONTROL VALVE…
• Ford 5.0L Thermactor Air Pump, Bypass Valve & Silencer Diagram - 1990 Bronco
  This document is a factory-style line drawing (schematic) showing the front view of a Ford V8 engine's Thermactor secondary air injection (emissions) system components. The illustration is labeled 'FRONT VIEW' with an…
• 1990 Ford Bronco 4.9L MT Thermactor Air Pump & Check Valve Diagram (A13526-A)
  This document is a Ford factory-style line drawing (illustration reference number A13526-A) showing the layout of the Thermactor secondary air injection (emissions) system on an engine, uploaded as applying to a 1990…
• 1990 Ford Bronco 4.9L Thermactor Air System Diagram - Air Pump, Bypass & Check Valve
  This document is a black-and-white line-art schematic (Ford illustration number A13527-A) showing the secondary air injection (Thermactor) system components on an inline six-cylinder engine, uploaded as applying to a…
• 1990 Ford Bronco 5.8L Thermactor Air Pump & Bypass Valve Location Diagram
  This document is a Ford factory-style line drawing (figure reference A9394-B) showing the Thermactor secondary air injection system components on a Ford V8 engine equipped with Electronic Fuel Injection, as indicated…
• Ford 5.0L Secondary Air (Thermactor) System Diagram - 1990 Bronco AIRB/AIRD
  This document is a two-part line-drawing schematic of the Thermactor secondary air injection system on a Ford V8 engine (filed by the uploader as the 5.0L system for a 1990 Ford Bronco). The left illustration shows the…
• Ford 5.8L Secondary Air System Diagram - AIRB/AIRD Valve & Air Pump Locations
  This document is a labeled schematic drawing of the secondary air (Thermactor) system on a Ford 5.8L engine, uploaded to a 1990 Ford Bronco gallery. The illustration shows a perspective view of the engine with an arrow…
• 5-Pin Automotive Relay Pinout Diagram - Terminals 30, 85, 86, 87, 87a
  This document is a schematic illustration of a standard 5-pin automotive relay, uploaded as part of a multi-image relay reference set for a 1990 Ford Bronco. The left portion shows the physical footprint of the relay…
• 5-Pin Automotive Relay Wiring Diagram - Pinout 30 85 86 87 87a Explained
  This document is a reference schematic explaining the pinout and function of a standard 5-pin automotive relay (Bosch/ISO style). The upper illustration shows the physical terminal layout on the bottom of the relay…
• 5-Pin Automotive Relay Pinout Diagram – Terminals 30, 85, 86, 87, 87a
  This document is an unlabeled schematic illustration of a common 5-pin automotive relay, uploaded to a 1990 Ford Bronco gallery. The left half shows the physical relay base with the blade terminal layout: terminal 5 at…
• Ford EEC-IV TPS Pinpoint Test DH Schematic - TP Sensor Connector Pinout
  This page (17-77) is from a Ford EEC-IV Pinpoint Test Procedures manual, covering Pinpoint Test DH for the Throttle Position (TP) Sensor. It presents the "Pinpoint Test Schematic" showing how the TP sensor circuit…
• Bolt Thread Pitch & Diameter Diagram - 1/2 Inch, 20 Threads Per Inch (SAE)
  This is a small illustrative diagram explaining how bolt/fastener thread specifications are measured. It depicts a threaded shaft (bolt shank) drawn in profile. Two dimensions are labeled: the "Diameter," indicated as…
• Lug Nut Seat Types Diagram - Acorn/Tapered 60°, Mag Seat w/Washer & Ball Seat
  This document is a technical illustration comparing the three common lug nut seat styles used on automotive wheels. Three cross-section diagrams show each lug nut type above a corresponding cutaway of the wheel's lug…
• Ford 5.0L / 5.8L HO V8 Firing Order Diagram 1-3-7-2-6-5-4-8 & Plug Wire Routing
  This schematic shows the firing order and spark plug wire routing for the Ford 5.0L and 5.8L HO (High Output) V8 engines. The diagram depicts a top view of the engine with both cylinder banks: cylinders 1 through 4 on…
• 1990 Ford Bronco Component Location View 151-12 – 165 Amp Alternator Layout
  This document is page 151-12 of a Ford factory Component Location View series, captioned "165 Amp Alternator." It is a line-art illustration of the engine compartment charging-system area with a numbered/lettered…
• 1990 Ford Bronco Frame Rail Component Location View 151-11 - Connectors & Sensors
  This is page 151-11 of a Ford component location manual (drawing FPS-12129-90, sheet 11 of 12), showing a "Frame Rail View" — an exploded-style illustration of the vehicle's frame/chassis with its wiring harness…
• 1990 Ford F-Series/Bronco Component Location View 151-10 - Full Body Connectors
  This document is page 151-10 of a Ford component location view section, captioned "Full Body View (F-Series)." It is a grid-referenced (columns 1–10, rows A–F) cutaway line drawing of an F-Series pickup body showing…
• 1990 Ford Bronco Component Location View 151-9 - Full Body Wiring Diagram
  This document is page 151-9, "Component Location View," from a Ford electrical/vacuum troubleshooting manual, showing a Full Body View of the Bronco. It is a line-art illustration of the Bronco body (doors, roof, cargo…
• 1990 Ford Bronco Component Location View 151-8 - Behind Dash Connectors
  This is page 151-8 of a Ford electrical vanline/EVTM-style reference, titled "Component Location View – Behind Dash." It presents a detailed line-art illustration of the dashboard area (viewed from behind) with a…
• 1990 Ford 7.5L Engine Component Location View 151-7 - Connectors & Relays
  This is page 151-7, "Component Location View," from a 1990 Ford Electrical & Vacuum Troubleshooting Manual (EVTM), figure reference FPS-12129-90 (7 of 12). It is the second of two component location illustrations for…
• 1990 Ford 7.5L Engine Component Location View 151-6 - Underhood Connectors
  This is page 151-6 of a Ford factory electrical/vacuum troubleshooting manual, titled "Component Location View," showing the first of two engine-compartment illustrations for the 7.5L engine. The line drawing depicts a…
• 1990 Ford 7.3L Diesel Engine Component Location View Diagram (Page 151-5)
  This document is page 151-5, "Component Location View," from a 1990 Ford electrical/vacuum troubleshooting manual (drawing reference FPS-12129-90, sheet 5 of 12). It presents a detailed top-down line drawing of the…
• 1990 Ford Bronco 5.0L/5.8L Engine Component Location Diagram - EVTM 151-4
  This document is page 151-4 of a Ford factory electrical/vacuum troubleshooting manual (EVTM), titled "Component Location View." It presents a detailed line-art illustration of the engine compartment for the 5.0L/5.8L…
• 1990 Ford Bronco 5.0L/5.8L Engine Component Location View - Diagram 151-3
  This document is page 151-3, "Component Location View," from a Ford electrical/vacuum troubleshooting manual, showing an overhead line-art illustration of the engine compartment for the 5.0L/5.8L engine (sheet 1 of 2)…
• 1990 Ford Bronco 4.9L Engine Component Location View 151-2 - Connectors & Sensors
  This document is page 151-2 of a Ford factory electrical/vacuum troubleshooting manual, titled "Component Location View," showing the second of two engine compartment illustrations for the 4.9L (300 cu in inline six)…
• 1990 Ford Bronco 4.9L Engine Component Location View 151-1 – EEC, Sensors
  This is page 151-1, "Component Location View," from a Ford factory wiring/EVTM-style manual, scanned from a 1990 Ford Bronco owner's document set. It shows an overhead line-drawing of the engine compartment for the…