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Ford Door Latch Cable Repair Tips and Tricks: 926-111

“Customer states rear door inop.” If you see that line on a ticket and the make and model is a Blue Oval truck or van, what you have is likely related to the door latch. Specifically, the cable end that operates that latch has cracked and crumbled. Ford will tell you...

Does Fuel Octane Rating Really Matter?

Life is full of small decisions. Pulling up to the gas pump, you are immediately faced with a choice: which octane fuel to use? The owner's manual for any vehicle should provide a minimum octane requirement, but is it worth filling up with a more expensive fuel with...

How to Make Your Own Molded Hose in a Pinch

When a vehicle’s vacuum or heater hose is in need of replacement, we tell the service writer, they sell the job and a little while later, a custom-formed piece with eleventy-four bends shows up, just like magic. But it wasn’t always this way. In Ye Olden Days, we’d...

Diesel and DEF – ASE Practice Question (VIDEO)

Description Technician A says that an empty DEF (Diesel Exhaust Fluid) tank can result in a “no start” complaint. Technician B says that the quality of the DEF fluid in the tank should be checked when SCR system faults are noted. Who is correct?A) Technician AB)...

EDC: Mechanic Edition

EDC, or “everyday carry” has become a popular topic of conversation. At first I thought people’s interest in this was a zeitgeist, but I think it’s got more staying power than I originally surmised. I used to (and still) roll my eyes when someone posts a beautiful...

The Most Neglected Part of the Cooling System

Cooling system jobs are, by and large, gravy repairs. Sure, we get the occasional hard-to-bleed system or the heater core that’s buried. But for the most part, the work is straightforward plumbing. And selling the stuff is easy! Even the most price-conscious customer...

When Selling a Job, Get It In Writing (Not an Emoji)

This one’s for anyone who interacts with customers directly: service writers, small shop owners, and even techs who do some moonlighting or side work. Be careful when using text abbreviations, slang, or emojis with your customer, and that goes double when a customer...

The Stories Spark Plugs Have to Tell (VIDEO)

Description In the days of carbureted engines, mechanics would always take a moment to examine the spark plugs they were replacing as part of a routine tune-up. The plugs often provided valuable information as to how well the engine was performing and whether there...

Check Out This Hacky Diag Tool

by | Apr 3, 2025

Disclaimer: Dorman Products purchased this kit at full price.

In the interest of serious investigative reporting, I swiped the Shop Press credit card for $14.83 to try out a diag tool I thought looked super-cool: the relay bypass. What’s that? Short version: Imagine a relay-shaped manual SPST switch.

Longer version: A relay, at its core, is an electrically actuated switch. A relay bypass replaces that function with a manual switch. Some bright soul got the idea to take six common relays and fit them with on-off rocker switches, the end result possessing the common “footprints” for automotive (“ice cube style”) relays. They can then be swapped into a vehicle fuse box or power center to give a technician manual control of the item receiving power.

Brilliant.

Now I thought Andy’s find of resettable breakers in a fuse footprint was interesting, but I was a little dubious about how often I might reach for them as a tech. But these babies? I feel a little differently.

What do I love here? A few things. I can test a component and its controlling relay for function at the same time. I don’t have to look up pinouts for common relays that I forget every time. I don’t have to open up a relay and put power to it to see if it’s working. I don’t have to build/scrounge/dig for stuff to make jumper wires. These sort of turn diagging relays from a painful punishment into something super-fast.

There’s really only one downside I can see: some of these are fitted with 10A switches, and they’re not fused. So, y’know, ya gotta use ‘em with caution or you’ll blow up one of your new toys. But that doesn’t seem like a very expensive proposition to me.

You know when I’m gonna use these? The next time someone brings me in a full fuel tank on a job where it needs to come down. Fuel caddy. Hmmph!

Now I thought Andy’s find of resettable breakers in a fuse footprint was interesting, but I was a little dubious about how often I might reach for them as a tech. But these babies? I feel a little differently.

What do I love here? A few things. I can test a component and its controlling relay for function at the same time. I don’t have to look up pinouts for common relays that I forget every time. I don’t have to open up a relay and put power to it to see if it’s working. I don’t have to build/scrounge/dig for stuff to make jumper wires. These sort of turn diagging relays from a painful punishment into something super-fast.

There’s really only one downside I can see: some of these are fitted with 10A switches, and they’re not fused. So, y’know, ya gotta use ‘em with caution or you’ll blow up one of your new toys. But that doesn’t seem like a very expensive proposition to me.

You know when I’m gonna use these? The next time someone brings me in a full fuel tank on a job where it needs to come down. Fuel caddy. Hmmph!

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