Failed light or dead circuit may seem like a trailer issue, but the problem could be in the tractor socket, 7-way pigtail or trailer-side connector. The 7-Way Round Pin Tractor Trailer Circuit Chaser® helps isolate the source by testing male and female 7-way round pin connections. Built-in LEDs confirm activity for key circuits, i.e., turn signals, hazards, brake lights, clearance lights, tail/tag lights and ABS. By checking multiple connection points, you can quickly determine whether the fault is in the truck, cable or trailer before replacing parts or chasing the wrong issue.
Compact and designed for one-man testing, the Circuit Chaser® is useful for troubleshooting on the road, or in the shop. The included brass jumper allows temporary bypass of approved circuits such as tail/tag, clearance or AUX when on the road. Use with an IPA® Mobile Universal Trailer Tester®, such as the Heavy Ranger® MUTT®, to check the trailer side.
How to Use:
Plug the Circuit Chaser® into the trailer-side end of the 7-way cable, bring the cable into the cab, and run through each lighting circuit. If one or more LEDs do not light, that circuit may be faulty. To help locate the problem, move the Circuit Chaser® to the tractor’s 7-way socket and test the circuits again. If the LEDs light at the tractor socket but not through the pigtail, the issue is likely in the cable. If the same LEDs remain unlit at the tractor socket, the issue is likely on the truck side. The Circuit Chaser® can also be used at the trailer’s 7-way connector to help identify trailer-side circuit issues.
Features and Benefits:
- Support one-man circuit testing: Activate each circuit from the cab without a second person at the rear connector
- Test both the pigtail and socket: Determine whether the fault is in the tractor, cable or trailer connection
- LED circuit indicators: Confirm each 7-way round pin circuit is receiving power
- Isolate electrical faults faster: Reduces guesswork by allowing comparison testing at the cable, tractor socket and trailer connector
- Bypass circuits: Includes a brass jumper for temporary bypass of approved circuits such as tail/tag, clearance or AUX
- Easy removal from connectors: Winged grip makes it easier to pull the tool from tight electrical connections
WARNING: This product can expose you to chemicals including Lead and Lead Compounds, which are known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to www.P65Warnings.ca.gov.
James Morris (verified owner) –
James Morris (verified owner) –
MARIO –
Save time to know what is wrong on the lights! I pulled different trailers and is very easy know what is wrong my truck or the trailer!
Dave –
Good product Works well and well-designed
Jose M. –
great product i recomended
Omar Nunez –
Great Tester About a year later still running strong and use it everyday !
Amazon Customer –
Great circuit tester Theme item is a Circuit tester that use on trailers. It works great.
Stephen Bates –
Can’t beat it A must for checking trailer 7 way connectors. They work great, I just always end up losing them.
john chapman –
Great I use this for my 10 trucks and 15 trailers. Easy to use.
Alexander Demidenko –
Save some bucks and time Really simple troubleshooting
bmwgeorge –
Nice tester I work as a chassis mechanic and I have to deal with truck drivers on a daily basis. this tester is great way to find out if you 7 way has as bad circuit which will tell you where to start looking for the problem. This item will help you find out if your semi truck 7 way plug is bad or if the chassis that your are hauling has the problem . keep in mind it is always best to use a metering device for the best readings but if you can afford one of those metering devices this 7 way tester will do the trick . I would recommend this item to my fellow chassis mechanics to help do quick trouble shooting on 7 ways
Jen –
Works good Thanks
Lionel Williams –
It’s useful in my line of work. The way it works.
Charles Washington –
priced just right great product
Michael George –
Works like it should I’ve gone through about 4 of these freakin things. And every time I lost one I bought another from snapon like an idiot. This last time I bought it here from amazon. Best decision I made. Way less money and it’s the same exact tool.
Tony Windon –
Easy to use it tells you if the problem is the truck cord or the trailer It’s easy to use save time which is money
j -jay –
100% accurate Every truck driver should have it.
Joseph McNevin –
Great product, well made, great quick diagnostic tool Great tool I use it all the time. tool helps you to quickly pin point whether there is a issue from the truck or trailer side of the lighting electrical system. Compared to my co-workers snap on version only obvious difference was a snap on logo and the significantly different pricing. Have had many truck drivers and other mechanics tell me they have never seen such a tool. Most of which say they are going to get one now. Have had it for a few months now and use it almost every day, so far it has held up. still looks brand new with no issues in functionality.
Winki –
Easy to use This little thing really speeds up the troubleshooting when determining the electrical problem.
Amazon Customer –
Awesome….. This product is amazing!!!
James –
When time is of the essence,this is the tool to have. I work for I’ve tractor trailer fleet …on drive up ,it make life so easy to tell if problem with 🚜 or trailer.glad I got it!