SW-EM Tech Articles

Tech Articles (Additions and Changes, ongoing! Last Updates: Oct 2024. Top of this List is the most recent.
An Article Listing by System can be found below!) Link to Feedback, Testimonials and Thanks.

D-Jet Injector Pulsetrain Notes

Pedal Position Sensing Brake Light Switch Variations on 122 Models

Electronic Upsets on Powerbuss cause Functional Dropouts on D-Jet Equipped Cars!

Removing an Amazon Oil Pan with Engine in Vehicle

Power Supply Susceptibility in Injected 140 Model

Checking the Calibration of Electronic Oil and Water Temp Gauges on 1800E and ES vehicles. A new subsection of Temperature Gauges 1800E/ES Notes Includes a section on calibrating Gauges on the bench.

Blower Motor Notes

Vacuum Leak at FI Intake Manifold ...at a somewhat surprising location!

Reverse Gear Affects Ignition!?!...or Whacky Ignition Function (WIF)

Courtesy Light Assembly 122/544 Notes

Window Lift Cable Repair

D-Jet Injector Maintenance and Service Notes

Gallery of Damaged and Broken Ignition Keys A new subsection of Ignition Switch Key Breakage Tech Article

Alternator Conversion of a 6V 444 Volvo A new subsection of Alternator in 6V Vehicles Tech Article

Emergency Flasher Variation in late production 122 A new subsection of Emergency Flasher Tech Article

Centering the Jet of an SU A new subsection of SU Jet Bearing and Supply Tube Notes

GEN Indicator in the 1800 A new subsection of AMP Indicator ON Tech article specifically covering the Generator based Charging System of the early 1800. Also added: AMP Indicator on the 1800E/ES models

1800 (Tail)lighting Stories. A detailed consideration of "Wacky Blinker Function". New Subsection of: Voltage Drops Cause Inadvertent Circuit Interactions

Heat from Heater/Defroster, when Control is set to COLD

B18/20 Heater Core Return Pipe

The Karl Heinz Option

1800 LHD Brake Light Switch Installation Feedback

Alternator in 6V Vehicles (...it's possible!)

US Delivered ESs have an "Overbite"!

Manual Rear Drum Brake Adjuster and Adjustment Notes

Cut-Out Contact Notes. Detailed info for those still running the venerable Bosch VReg/Generator Charging System.

Rear Brake Valve Notes

Temperature Gauges 1800E/ES Notes ...the latest chapter in the story of "Overheating Vehicle - are you sure?" ...added: Troubleshooting Info

High-Side Switching vs. Low-Side Switching

Girling 3 Piston Brake Caliper Rebuild Update: Documentation of Caliper Reassembly added!

"Sheet Pasta Gone Wrong" revisited!

L3314HD Laplander Alternator Conversion

"Starter Cutout and Reversing Light Contact" on (BW35) Gearbox ...including disabling / bypassing this function as an Emergency Repair.

Discovery: Mismatched Threads on All Amazon Braking Systems with Hydraulic Brake Light Switches(!) ...subsection of Brake Notes

D-Jet Idle Adjustment, includes Throttle Position Switch Suggested Maintenance.

1800E Brake Lock-up due to Lack of Free-Play

D-Jet Manifold Pressure Sensor

Amazon Rear Light Fixture Maintenance. Subsection of Amazon Rear Light Fixture Restoration

Incorrect Assembly of Rear (Drum) Brakes on 122 and 1800 Vehicles causes Risk of Handbrake Failure.
Be certain you assemble your Rear Brakes right! Subsection of Brake Notes

Alternator Installation Failure Report and Analysis

544 Intermittent Wiper (after 6-12V Conversion) Notes by Guest Contributor Richard Allen.
Subsection of Vintage Volvo 6V to 12V conversion

Practical Applications of Soldering, as Applied on a Vintage Volvo ...new subsection of Wiring Notes

Previous Owner Service and "Engineering"...new subsection of Amazon Tail-light Fixture Restoration Notes

Footswitch Hi/LoBeam Notes Both Bosch (544, 122) and Lucas (early 1800)

Late-Production Ignition Lock Removal

Carburetor Additional Notes

"Smoke in the Cockpit!"...THAT...will always get our attention!

Fuel Delivery Components and Considerations ...a new subpage of the SU Carbs Page

Original Equipment Oil Cooler Notes

1800 Wiper Switch Disassembly, Reassembly, and Review...a new subsection of 1800 Light Switch, Wiper Switch, Fan Switch Drawing Corrections

122 Instrument Panel Indicator Lens Graphics Repair Notes Are the graphic no longer nice and crisp on your Combined Instrument? Here is the solution!

Third and Strobing Brakelight Notes...improving the visual signature when braking...

Two Wrongs make a Right! (Electrically Speaking!) Troubleshooting very unusual symptoms...

Wiper Parking Side Notes (or, Right is Right, for LHD, and Left is Left, for RHD!)...including Reference Information by Guest Contributor John Finn on Wiper Assembly Removal from an 1800S (without Dashboard Removal!)

Fuel Tank Notes

Check your Distributor Cap Brush! The tiniest little components can be quite important!

Headlight Notes Footswitch or Stalk control of Hi/Lo Beams, addition of Foglights and Driving/Spotlights are covered. Details on Bistable Control Relay are located here.

Dual Ignition Switch Special Configurations for 122 and 1800 Models

123GT FuseBlock Rework Related Page: FuseBlock Core Notes

MP3 Player for Volvo AM Radio by SW-EM Guest Contributor David Smith Sub-page to the Radio Notes page.

Disassembly Review and Reassembly of the 1800 Light Switch ...a new subsection of 1800 Light Switch, Wiper Switch, Fan Switch Drawing Corrections

SU Carb. Adding Threaded Inserts for Air Cleaner Securing

Amazon Lightswitch Review and Notes ...quality always stands the test of time!

Corrosion on 1800E and 1800ES Fuseblocks.

Horn-Wire Replacement ...newly revised subsection of 122 Horn Notes.

Trunkseal and Fuel Filler Compartment Drain (1800) Notes ...a somewhat hidden potential source of (big) problems.

Trunk-lid Torsionspring Notes ...for 122 and 1800 owners.

Courtesy Light 1800 Information and Notes Simple! ...but with a couple of twists.

Water on the Floor Whether from Windshield, the Cooling System, or Heater Enclosure, leaks are never a good thing.

Fuel Gauge 1800 Information and Notes Different from 122 Fuel Gauge Notes, which is covered here: Fuel Gauge Information and Notes

What's Worse than a Metal Portobello? Subsection of Brake Drum Notes

Relay Controlled Headlights, a subsection of Lighting Notes, including Upgrades.

Momentary vs. Continuous Duty Relays, a subsection of Ignition Slave Relay. More info comparing 3, 4, 5 terminal relays here.

Inspection of Fuelbowl Lids, Floats and Bowlvalves...newly revised subsection of SU Carb Service Page...information for those who have experienced overflowing SU Bowls.

Wiper Park Function explanation and differences between Motor without, and Motors with, Dynamic Braking ...a subsection of Windshield Wiper Systems.

Voltage Stabilizer Notes ...not to be confused with the Voltage Regulator, which controls the Charging System, the VStab is important for the correct operation of the late (injected) 1800 (10V rated) and 140 (5.1V rated) Instruments.

The Handbrake Turn ...less of a Tech Article, but containing important information!

Setting the SU History Record Straight

Broken Vintage Volvo Ignition Key... immediate action and options.

Driveshaft and U-Joint Notes

Considering LED Replacement Lamps ...subsection of Amazon Tail-light Fixture Restoration

Wiring Notes, including: Crimp terminals, Tools, and making a Proper Crimp, and Soldering Notes

Cooling System...from theory of operation to installing that Electric Cooling Fan you've been considering.

Timing Gear Notes

123GT (Alternator based) Charging System Notes ...added 1800E Charge Sys Info as Alternator based Chg Sys are similar.

Radio Notes ...a collection of information about Radios in a vintage Volvo.

Manifolding Notes for B18/20 Motors

SU Carb Throttle Plate Early vs. Late including notes on the Throttle Overrun Valve

OR-ing Circuit Notes

Brake Notes

Ignition Slave Relay ...spare your vintage Ignition Switch from additional high currents!

Wiper Arm and Blade Notes

Wheels, Tires, Suspension Notes .

Bosch Starter Solenoid. Subsection of The Starter System

Directional Indicator Switch Mechanism for 122 and 1800 vehicles.

Fuse your Cigarette Lighter! ...new subsection of Fuses, Allocation and Troubleshooting

Understanding the Failure of a Diode ORing Cable used with Electronic Ignition Module...subsection of Volvo Ignition from Scratch.

Proving Everything Bad you Ever Heard About Lucas ...subsection of An Automotive Electrical Primer

Coolant Distribution Pipe Notes

123GT Reliability Weakness and Simple Improvement Prevent the inadvertent disconnection of the vehicle Battery from the Alternator, while engine is running!

Omega Clip Notes for when removing and Reinstalling Door Handles and Window Cranks.

544 Wiper Info included is a subsection with info on installing a Two-Speed 140 Wiper Motor in a 544, by guest contributor Michael Krarup.

Clutch - Cable Actuated, Notes

Blinker Relay (or Element) Notes. While Troubleshooting Directional Signals, one might need to know details about the Blinker Element. Wiring Diagram Extracts for 544, 122, 1800, 1800ES models are included.

Houdini Threadlocker? or There is no Loktite thief in the South African Postal System!

123Ignition in a Volvo with Armored Cable Details of installing electronic ignition modules are considered to help installers get it right!

Torque...what it is, notes on applying and measuring it, including advice from Arnie!

Battery Notes ...got Battery issues?...like your Battery going dead overnight or related questions? Read about the demon Phantom Current, including in battery powered handheld devices.

Notes on Making In-Line Connections... Do Not Use "Current-Thieves"! This is a subsection of Emergency Flasher Retrofit for 122/1800 ).

Alt Kit Pivot bolt with a "Drunken Thread"! You learn something new every day!

Alt Kit Additional Info Page. Information for the well informed installer of the Sw-Em Alt kit.

Bosch Generator based Charging System in Detail. Everything you always needed to know, and them some!

Bosch D-Jetronic Fuel Injection Notes Compilation. Including Throttle Position Switch (TPS) information and repair options.

Run-In Torque (this is a subsection of Anti-Seize Notes).

Realworld Experiences with Electrical Corrosion and ACZP.

Voltage Drop in Headlights Power in Hex Connector Applicable to 122 and late 1800 models. Includes subsection: The Lowly .250" Push-On Terminal

Temperature Gauge Notes The Temperature Indicator System of pre 140 vehicles is a filled thermal system not needing power to function, but careful handling to keep functioning! Overheating vehicle...are you sure?

Fuel Gauge Information and Notes Applicable to 444, 544, 122, (6/12V) but not 1800 models. For that, see: Fuel Gauge 1800 Information and Notes

Smith's Tachometer Information and Notes As used in all 1800 Sport models. New info added recently on how to tell Gen 1, 2, and 3 versions apart. Tach not working? See also: Two Wrongs make a Right! ...sometimes it really can be as easy as simply tightening a loose thumbscrew!

Anti-Corrosive-Zinc-Paste for Electrical Connections and the additional: Simple Corrosion/Oxidation vs. Galvanic Corrosion and Comparison of Anti-Corrosive-Zinc-Pastes.htm

Ignition Switch Key Breakage Weak keys vs. the Gorilla Spring, vs. Cumulative Cyclic Fatigue

1800 Light Switch, Wiper Switch, Fan Switch Drawing Corrections includes a detailed Disassembly Review and Reassembly of the 1800 Light Switch

Voltage Drops Cause Inadvertent Circuit Interactions

SU HS6 Jet Supply Line Seal

123GT Consideration of Lighting Differences ...significant differences in lighting control wiring between US and Euroversions are detailed.

Fuses, Allocation and Troubleshooting ...including 25A shorty fuse options, and fusing improvements and explanations pertaining to 35A (British) rated fuses specified for early P1800s.

Deoxit D5 Additional Keeping your low voltage/low current connections reliable...

Brake Drum Notes No, drum is not welded to axle, it only seems that way...remove it safely without damaging hardware or liveware (you)!

Heater Control Valve 122 ...added: P1800 Version of Ranco H16 HCV

Variable Instrument Lighting function and options for repairs of its common intermittency are covered.

Ignition Additional...Ignition System Troubleshooting, Wifes Startautomat (Huh?), Ballast Resistor.

Swedish vs. British Design...there are some interesting differences between Amazon and 1800 Ignition wiring...and I've uncovered a reliability weakness in the 1800 design.

122 Horn Notes...revision of an older article, covering electrical improvements and refurb of the Amazon horn-switch.

Amazon Tail-light Fixture Restoration once the brake light switch works well, it's good to know your tail-lights are putting out all the light they can! Includes notes on LED conversion and Third and Strobing Brakelight Notes.

Windshield Wiper Systems...more variations than Carter has Pills, and errors in the factory manual don't make things any easier! Refurb and repair of motors, mechanisms and circuits is covered here.

Hydraulic Clutch Tech Article...!

Electrical Upgrades / Buzzers and Beepers covers adding a Relay for powering additional loads without additionally burdening the OE Ignition Switch...also adding a Headlight-On Reminder Beeper in your Swedish Oldie!

Hydraulic Brake Light Switch Failure Investigation ...here's proof why they just don't last...

AMP/GEN Indicator ON. This article is intended to answer questions, when that little Red light lights up and starts staring at you! Including Original Equipment Charging System Checks, Troubleshooting and Repair!

Analysis of the clutch slave cylinder action. Superceded by: Hydraulic Clutch Tech Article, and due to be removed.

Carburetters. Maybe you've read it all before...maybe not! Also: SU Carb Service - Lite ...an introduction, and Carb Service - Expanded Version, with Adjustments. Setting the SU History Record Straight!

SU Jet Bearing and Supply Tube Notes

Lighting Notes, including Upgrades Includes brake-light issues.

Volvo Ignition from Scratch Lighting the fire ...at the right time! Static Timing a B18/20, plus: Bosch distributor servicing including Centrifugal Advance. Recently added: Vintage Volvo Ignition system and the Armored Cable.

The Gas Tight Joint Part II, Lucas works inexcusable (dark) magic on the 1800. After you read this maybe you'll understand about those unexplained electrical problems in your 1800...

(Full) Headlight control upgrade. (For 122s and 1800s.) This article superceded by Headlight Notes, and due to be removed.

Reviving a 'Decommissioned' Volvo

If Cars could talk or History of the "Jupiter V Rocket No.3"

A Tune-up out of Guilt or One Set of Points Outlasts the Clintons

Check Your Choke . . . just in time for (maybe next) winter!

Electrical Ramblings Covers Amp meter hook-up per "H" diagram, including an objective discussion of automotive Ampmeters vs. Voltmeters to help one decide which to install.

Of Unleaded Fuel and Burned Valves

A Funny Thing Happened on My Way to my 200K Mile Badge Oops.