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Watch This Video On Dry Sump Oil Systems

Recently, I was talking with Shop Press head honcho (Chief Bottle Washer—Ed.) Lemmy about something I wasn’t familiar with: dry sump oil systems. If you’re a newer tech who hasn’t worked on any high-end sports cars, you also might not be familiar with these systems....

Tariff Talk: A Look Backwards at The Chicken Tax

Well, the mood’s been a little heavy with all the talk about tariffs as of late. There’s an automotive tax that’s been around for a long time that is a perfect thing to mention if a conversation is getting uncomfortable. And if you’re a car nut, you should at least...

Watch This Video on the Inventor Who Put Lead in Gasoline

Recently, I went down an internet rabbit hole about why gasoline once had lead in it and how it got removed. In my searches, I found this video on inventor Thomas Midgley Jr., who not only invented leaded gasoline to combat engine knocking but also synthesized...

Stress Test Vehicle Grounds

Pop quiz, no cheating: how many amps does the ground side of any circuit conduct? If you said, “As many as the hot side,” get yourself a gold star and skip this article. For the rest of us who weren’t born innately knowing the answer to that question, stick with me...

The Tightwad’s Way To Install Any Wheel Bearing Race

I don’t own a bearing race driver kit, and I haven’t in 20 years of fixing stuff. I also refuse to use sockets to drive a race. I learned a method a long time ago I’ll pass along to you newer techs: I use the race I’m replacing. I primarily have used this trick when...

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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