Automotive electrical diagnostics

[SuzukiGS750EZ]

What do you guys swear by for diagnostic tools or helping aids. For example, DMM, Powerprobe, fusebuddy, load pro, test light, e.t.c. little gadgets, relay testers, fuse testers. List em here!

 

[Alienbaby17]

I love my Powerprobe. Before I bought it I thought it was kind of an extravagant purchase. That was many years ago. It has become one of my most used tools that I would never hesitate to buy again if something happened to my current one. I don’t even know where my old school test light is any more.

 

[Bogie1632]

Quality multimeter with accessories (amp clamp, probe attachments), Powerprobe IV (ditched old school circuit testers a few years back), ALLDATA subscription (as needed now that I'm semi retired), scan tool. Those are my go-to items but for diagnostics there are many others that come in handy depending on what the need or problem is.

V/R
Bogie

 

[Daves69]

Old school test light for quick check of fuses and testing turn signal circuit. DMM for voltage. Test leads and pins for back probing connectors

 

[SuzukiGS750EZ]

I've lately come across fuse buddy, fuse saver (recommended by somebody on this forum). I've used my load pro with my fluke 179 a bunch. ECT 2000 & powerprobe 3. Bluedriver/innova/actron scan tools. Test light. I forget what else I have...

 

[2ndGearRubber]

Test lights and bulb setups with known amp draws. A meter you can trust, and long leads. Lots of back-probes and gators. The 10/15/25 foot retractable test leads are nice for dedicated power and ground. Really that stuff and a wiring diagram won't steer you wrong. My loadpro leads and power-probe 3 sit in the box anymore. Fuse and relay jumpers, the AESWAVE super-connector kit.



Above all, a scope and all the goodies to make the most of it. And my trusty test lights.

 

[setfocus]

I've got a pretty basic auto ranging macto DDM, basic snapon test light, and power probe 3S.

I don't do much electrical, just some of the simple quick stuff like checking for power and ground, replacing a connector pig tail

 

[RTM]

Back in the days when cars were simple, I used an idiot light for 90% of my trouble shooting. Nowadays you need brand specific stuff on top of the OBD to turn stuff on, force signals, read pulses....

 

[richfinn]

Scantool with bi-directional capabilities

Scopemeter or Pico

Current clamp (compatible with scope)

Incandescent test lamps

Midtronics battery tester

Good wiring diagrams/info

Mityvac (dual pressure/vacuum type)

Really good quality head torch (to identify wire colours when your eyesight ***** and you need both hands free to probe circuits and push buttons etc)

Good test leads and accessories (pomona stuff is good)

Fuel pressure test gauge and adaptorspp

 

[RedneckWelder]

Fluke 87V is my DMM of choice. Results you can trust.

I like my Powerprobe 3 but when you have to diagnose CAN circuits and similar it’s not as useful. Great for straight power and ground stuff like lights and such. Also is nice as a fuse checker.

I have an Amp clamp for certain situations

You also need a drawer or tackle box full of random stuff for troubleshooting...jumper wires, components like potentiometers for checking sensors, custom test lights etc

I have the master fuse saber set

 

[theoldwizard1]

Fluke 87V is my DMM of choice. Results you can trust.

Not always. It will show you voltage, but not if there is enough current to sustain that voltage !

 

[zmotorsports]

My suggestion is if you aren't familiar with the circuits on modern cars then resist the urge to use a test light. I've seen inexperienced users probe around with them and cause more issues due to the higher current load of the bulb vs. the sensors that are being tested.

That being said, I would say my go to tools are my Fluke 87, Snap-on Modis Ultra scanner/scope, Powerprobe and array of adapters to back-probe connectors. I also use my Midtronics tester quite a lot for charging and starting system diagnostics and if the symptoms call for it I'll use my carbon pile tester to load the charging system and test output.

Lastly I would also suggest resisting the urge to pierce holes in wires for diagnostics. This can lead to more difficult to diagnose issues down the road after corrosion sets in. Use the proper tools to backprobe connectors and test components properly.

 

[setfocus]

getting into more of the driveability side of things, I've got a Launch Millennium 90, aka glorified code reader that has ABS, EVAP, O2 sensor, steering angle sensor, oil light controls on some cars

My previous shop had an old snapon solus pro that wasn't updated for awhile. It went missing/stolen and they didn't want to replace it, so I bought the glorified code reader to get by. We didn't do much driveability.

Current shop has a solus edge and we do more code scans and work on more european cars than my old shop. I just go straight for the shop scan tool. The code reader is a pita to use for more than grabbing/clearing codes and has missed an engine code in the past. I work at a full service tire shop, the majority of the work I do is steering, suspension, brakes, light engine repair (alternators, water pumps, and such). I use Identifix alot, if the testing is overly involved or I can't find any fixes, and can't figure it out on my own in a timely manner, I refer them to the dealer

 

[SuzukiGS750EZ]

My suggestion is if you aren't familiar with the circuits on modern cars then resist the urge to use a test light. I've seen inexperienced users probe around with them and cause more issues due to the higher current load of the bulb vs. the sensors that are being tested.



That being said, I would say my go to tools are my Fluke 87, Snap-on Modis Ultra scanner/scope, Powerprobe and array of adapters to back-probe connectors. I also use my Midtronics tester quite a lot for charging and starting system diagnostics and if the symptoms call for it I'll use my carbon pile tester to load the charging system and test output.



Lastly I would also suggest resisting the urge to pierce holes in wires for diagnostics. This can lead to more difficult to diagnose issues down the road after corrosion sets in. Use the proper tools to backprobe connectors and test components properly.

X10 on piercing holes. I can't tell you how many times "the green stuff" has crept up wires I've found as in diagnosing... and if you do, SEAL IT.

 

[VinceG]

I use a Snap-on Multmeter, amp,clamp Load-pro, Hantek scope, Various back probes electronic specialties 149 probe kit. Matco Maxme scanner Snap-on EECS350 battery tester, harbor freight carbon pile tester. yes this is my home set up

 

[pwschuh]

Powerprobe. Just get one.

 

[signcrafter]

The 10/15/25 foot retractable test leads are nice for dedicated power and ground.

That's about all I use my power probe for anymore. Has a long cord and a power and ground. Also bought the 5V adapter for it so you can have a good reference signal for testing sensors. Also bought the switch cover plate so it can do constant power without having to hold the switch. Kind of an expensive power supply cord but I bought it 10 or so years ago and didn't use it much besides for power and ground supply. Nice to have a voltage reading on it too when using it as a power supply since my meter is usually measuring something else. I can also connect all the adapters from my test lead kit to it so it makes it super easy to power up a blower motor or something. Used to use a lead set with alligator clips and it was always a pain to try and hook it to things. I use the spade terminals all the time to test from the relay, super fast and easy to break into a circuit and narrow down which part of that circuit is the fault.

My main tools are my fluke 87 and a big test lead kit. The test lead kits are expensive but mine has paid for itself many times over. So nice to be able to get into connectors and parts and what not. Also has backprobes and alligator clips and all sorts of stuff. Just plug and play whatever connections you need and can test all sorts of things. Also have amp clamps and some other things to go with it.

Besides my meter I use a variety of mostly homemade testers and adapters. I have battery adapters for doing parasitic drain tests, tail and headlight sockets for doing circuit tests, fuse adapters to get into fuse boxes, sealed beam bulb for finding shorts, and much more.

Another tool you can't really live without is a bi directional scan tool. It's pretty much a must for working on newer cars.

 

[fordnut85]

What do I swear by? Other than the typical test light, dmm, power probe and scope my top picks are:

Low amp probe
5v adapter for the power probe
an assortment of lights like turn signal bulbs and headlights with known amperage
ASE wave adapter kit

 

[2ndGearRubber]

I tired to love my power probe, and it's a good tool. I've just gone towards known-amp-draw test light/bulbs. I buy stacking banana jacks on amazon, as well as fuse holders, so all of my test light pieces are interchangeable and fused. You can use the the fuse section as a fused jump wire too. Another favorite is to take a de-pinned pair of 02 sensor wires, add a fuse holder in between them, and you have a fused jump wire with pre-installed spade terminals. I have a PP3, and while it does have uses, I find my bulbs and fused jump wires have become my go to.

Most of the power-it-up power probe tests I just bypass with a known amp load. Had an inop blower motor last week. Well a 5amp test light burns bright off the input power and ground, no need to mess with testing the motor. Nose bearing had failed, dragging the com-bar away from the brushes. That was on high, I had no light on settings 1-3, resistor had also failed, customer just didn't mention it in the initial complaint. Had driven it with only speed 4 for over a year.

 

[bwringer]

an assortment of lights like turn signal bulbs and headlights with known amperage

Several folks have mentioned these, and I have several homemade versions.

Does anyone make such a thing in a nice package where you won't burn your fingers on a hot bulb or hit something you don't intend to with a terminal?

Maybe one you can switch between different bulbs or loads? With a buzzer?


Amp clamps that can read DC have also been mentioned a few times. Incredibly handy, but oddly hard to find.

 

[richfinn]

Several folks have mentioned these, and I have several homemade versions.

Does anyone make such a thing in a nice package where you won't burn your fingers on a hot bulb or hit something you don't intend to with a terminal?

Maybe one you can switch between different bulbs or loads? With a buzzer?


Amp clamps that can read DC have also been mentioned a few times. Incredibly handy, but oddly hard to find.

AC/DC clamps are a little more expensive but readily available, try AESwave/Fluke

I have a selection of bulbs wired up for load testing I haven't seen any "packaged into a retail tool" yet!!!

I also use the stacking leads

I have a H4 bulb inside an old plastic cap from a WD40 can that I use for finding dead shorts and loading circuits

 

[2ndGearRubber]

Several folks have mentioned these, and I have several homemade versions.

Does anyone make such a thing in a nice package where you won't burn your fingers on a hot bulb or hit something you don't intend to with a terminal?

Maybe one you can switch between different bulbs or loads? With a buzzer?


Amp clamps that can read DC have also been mentioned a few times. Incredibly handy, but oddly hard to find.

https://www.amazon.com/dp/B00X3GDVWM/?tag=atomicindus08-20

DC amp clamp.

The ones built onto the top of a standard meter aren't that helpful IME. If I want amps I usually want it graphed. The above clamp is sold by numerous venders in banana or BNC end. The scales fit snap-ons low/high amps settings as well, which is nice. I have two of these, one from PDI, the other from AESWave. It's pretty rare I desire more than 2 amp clamps at the same time, and the Pico and Modis are both 4 channel scopes anyways.

 

[Bobioz1]

I tired to love my power probe, and it's a good tool. I've just gone towards known-amp-draw test light/bulbs. I buy stacking banana jacks on amazon, as well as fuse holders, so all of my test light pieces are interchangeable and fused. You can use the the fuse section as a fused jump wire too. Another favorite is to take a de-pinned pair of 02 sensor wires, add a fuse holder in between them, and you have a fused jump wire with pre-installed spade terminals. I have a PP3, and while it does have uses, I find my bulbs and fused jump wires have become my go to.

Most of the power-it-up power probe tests I just bypass with a known amp load. Had an inop blower motor last week. Well a 5amp test light burns bright off the input power and ground, no need to mess with testing the motor. Nose bearing had failed, dragging the com-bar away from the brushes. That was on high, I had no light on settings 1-3, resistor had also failed, customer just didn't mention it in the initial complaint. Had driven it with only speed 4 for over a year.

Lower speed settings in a blower motor circuit might not light a 5 amp test light.

 

[sreeb]

ut210e clamp multimeter. Clamp does dc current measurements in the mA range. Cost <$50.

Nothing else like it on the market anywhere near the price.

Ancel pb100. Probably "inspired" by the power probe but definitely its own design.

 

[Sine Swept]

Logic probe, long leads with battery clips and 12 volt outlet - for logic probe to go off front battery. 9 volt battery popper with momentary switch for speaker polarity testing. Meter with audible continuity tester.

 

[2ndGearRubber]

Lower speed settings in a blower motor circuit might not light a 5 amp test light.

Fully aware. I switched to the 2amp, then the 1/4 amp lights, still no output. Should have mentioned that step. Relay was open aside from full speed, customer reported the fact it didn't work on speeds 1-3 when they came to pick it up wondering if that was also fixed. Which it was.

 

[Bobioz1]

Fully aware. I switched to the 2amp, then the 1/4 amp lights, still no output. Should have mentioned that step. Relay was open aside from full speed, customer reported the fact it didn't work on speeds 1-3 when they came to pick it up wondering if that was also fixed. Which it was.

 

[928'er]

https://www.amazon.com/dp/B0012VYKOS/?tag=atomicindus08-20

Cheap enough to leave in the glovebox. Major step up from the HF freebee...

 

[pelletman]

https://www.amazon.com/dp/B0012VYKOS/?tag=atomicindus08-20

Cheap enough to leave in the glovebox. Major step up from the HF freebee...

That looks like the Craftsman meter that was often on sale for 10 bucks. Good deal.

 

[bwringer]

My DC amp clamp meter is a Craftsman; the only one I could find at the time under $100. It works great and has been extraordinarily useful.

Harbor Freight now has an "Ames" brand meter ($90 without discounts) with a DC amp clamp that can go up to 600A.


Interesting that no one makes a test light with switchable loading, or at least we haven't heard of it. It's one of those things where it's important to have an actual incandescent light bulb filament; you can tell a lot by how brightly it's glowing, whether it's steady or wibbly, etc.

For that matter, with a bit of experience, you often don't really need to get a number to tell what's going on with 12V systems. The glow from your test light tells you whether you're getting healthy voltage in many cases.


One other very handy item I have is a meter with both an old-school needle and a digital display. I inherited one from my Dad (no idea where he got it), and it's been very useful many times. Sometimes the digits won't settle down, and the needle can tell you more easily where you are. And often the speed or twitchiness of the needle's response will tell you something you need to know.

 

[Lassen Forge]

I love me my powerprobe - once I learned how to use it, it became a go to tool... man, I should have gotten one of those before.

Also my Autel codereader - it's not a full scanner but it will read (and clear) codes. And it powers off the OBD2 port, so no batteries required. No, it's not as cool as a 906, but for Q&D stuff it's just fine.

Add to that list my AESwave pocket scope - it's a one channel oscilloscope that fits in a shirt pocket, and anything that has to do with reading or researching a signal of any kind (except service line voltage - they warn you that it's only good to about 60 volts...) it's become darned near priceless...

Between the 3 above, I have no idea how the heck I made do without them now with just a VOM...

 

[upper_tanker]

I've been using a Power Probe for a few years now and I love it. Just last year, I bought this:
https://www.tooldiscounter.com/prod...TQ9Da64-eUNhBwpZT9ILF6CcGZXJkThBoCrz4QAvD_BwE

I WANT to love it, but I just can't figure the damn thing out... probably because I'm an idiot.

 

[richfinn]

I've been using a Power Probe for a few years now and I love it. Just last year, I bought this:
https://www.tooldiscounter.com/prod...TQ9Da64-eUNhBwpZT9ILF6CcGZXJkThBoCrz4QAvD_BwE

I WANT to love it, but I just can't figure the damn thing out... probably because I'm an idiot.

Your not an idiot, nobody gets along with that tool

 

[Lassen Forge]

I don't have one, but if I read it correctly it's like an underground wire chaser, it puts a radio signal in the wire, and when the signal goes away on your detector, you found your break in the wire...

Hell, I think this means I need to spend money on another gadget. Thanks a LOT!

 

[RedneckWelder]

I've been using a Power Probe for a few years now and I love it. Just last year, I bought this:
https://www.tooldiscounter.com/prod...TQ9Da64-eUNhBwpZT9ILF6CcGZXJkThBoCrz4QAvD_BwE

I WANT to love it, but I just can't figure the damn thing out... probably because I'm an idiot.

Your not an idiot, nobody gets along with that tool

I’ve heard people say they use an Ethernet style signal generator and tracer with good effect on automotive wiring

 

[mfewtrail]

I've been using a Power Probe for a few years now and I love it. Just last year, I bought this:
https://www.tooldiscounter.com/prod...TQ9Da64-eUNhBwpZT9ILF6CcGZXJkThBoCrz4QAvD_BwE

I WANT to love it, but I just can't figure the damn thing out... probably because I'm an idiot.

I linked someone on here in a recent thread to these videos showing how to use the tool.

English demonstration:

Spanish demonstration:

 

[SuzukiGS750EZ]

I have the pp3 kit with the ect 2000, it does work & well too. It saved me from undoing an entire main harness loom. I'll actually be using it again in the spring to help someone at work with a headlight short. I was able to get one headlight working but the other has a short. Too damn cold out right now to mess with it.

 

[Aileron]

Anyone with the Powerprobe able to comment on the warranty. I've been eyeballing them and looking at the probe iv master kit or getting the Maesrto and also ect3000 kit. The link above looks to be the best price with Amazon around 15 or more dollars higher. From some of the reviews I have been reading, people are getting the warranty denied on account of where it was purchased from. Power probe wouldn't honor the warranty because it was not purchased from "their dealer" and the sellers where telling the customer too bad go back to manufacturer. Some of the reviews where from Amazon and granted some are third party seller but Amazon is also listed in the Power probe tek sight as one of their partners. I wouldn't really care about a tool under a hundred or so but we are looking at a few hundred and afraid of getting a dud from the get go. I know right now I probably would not use it for a while and hate to find out after a month or two its not right.

 

[theoldwizard1]

Interesting that no one makes a test light with switchable loading, ...

I asked Chris from Astro about this once. He said he brought it up to "the powers that be" and no one thought it was a good idea.[/QUOTE]

 

[SuzukiGS750EZ]

Welp... I ordered the MS906TS for $1,450. I hope i'm happy with it...