Troubleshooting Power Isues With the Bulldog Velocity Jack
Updated 07/05/2018 | Published 07/03/2018 >
Question:
the jack worked fine before installation-upon lifting the trailer off the truck-as soon as there was a load the jack shut off and will not go up-goes down fine. using 2 6-volt batteries but they put corrosion paper behind the flanges to protect the alum. trailer.
asked by: Deb R
Expert Reply:
According to the details you told me, it sounds like you are running the Powered Drive Trailer Jack # BD500199 off of a battery on the trailer.
Does the problem you describe always occur when the jack as at a particular height? If so, the jack tube might be slightly bent. The bend would cause the jack to bind once it reached a certain height. Manually operating the jack would extend or retract the jack past the point where the tube is bent, at which time the motor would be able to move the jack. It is not too difficult to slightly bend the jack tube if it was accidentally left partially extended while the trailer was moving and an obstruction like a speed bump was hit.
Using the two 6 Volt batteries, you will should not have an issue powering the jack if they're wired in series. The jack grounds through the mounting hardware and not a ground wire. Aluminum doesn't make a good ground. If this does not work for you let me know and I will provide more assistance.

Product Page this Question was Asked From
Bulldog Powered Drive Trailer Jack - Drop Leg - A-Frame - 22" Lift - 4,000 lbs - Black
- Camper Jacks
- Pop Up Camper
- Teardrop Camper
- Travel Trailer
- A-Frame Jacks
- Steel
- 3001 - 4000 lbs
- Electric Jack
- 22 Inch Lift
- Bolt-On
- 1 Jack
- Bulldog
more information >
Featured Help Information
Instructions
Miscellaneous Media
Continue Researching
- Video: In-Depth Review of the Ramp Gate Seal Kit for Enclosed Trailer Ramp
- Search Results: ramp door seal
- Shop: Ramp Gate Seal Kit for Enclosed Trailer Ramp - Half Round Seal - 35' Long x 11/16" Tall
- Q&A: How to Choose Best Thickness for Ramp Door Seal Kit
- Video: Review of Bulldog Replacement Trailer Jack Spring Loaded Pull Pin - BD500388
- Article: Towing a Trailer? Let's Talk About Brake Controllers
- Article: My Trailer Hitch Doesn't Fit
- Search Results: bulldog electric jack
- Shop: Ramp Gate Seal Kit for Enclosed Trailer Ramp - Ribbed Hollow Bulb Seal - 35' Long x 1" Tall
- Q&A: Can The Bulldog Powered-Drive Trailer Jack # BD500199 be Installed in a 90 Degree Orientation
- Q&A: Is Welding Required for the Handle on the Cam-Action Lockable Door Latch Kits
- Q&A: Can Leg on 4000 lb Powered Trailer Jack Be Replaced
- Q&A: Troubleshooting The Bulldog Powered A-Frame Jack That Does Not Go Down
- Shop: Cam-Action Lockable Door Latch w/ Split Bushings for Large Enclosed Trailers - Stainless Steel
- Shop: Side-Door Bar Lock Assembly - 55" Long
- Shop: Cam-Action Lockable Door Latch Kit for Large Enclosed Trailers - Zinc-Plated Steel
- Shop: 45" Long Side-Door Bar Lock Assembly
- Shop: Replacement Spring Loaded Pull Pin for Bulldog 4,000-lb Electric A-Frame Trailer Jacks
- Video: Hands-On with the Ramp Gate Seal Kit for Enclosed Trailer Ramp
- Search Results: ramp door bumpers
- Q&A: Recommended Bulb Seal For An RV Ramp Door
- Q&A: Direction of Equalizer # TREQ105 When Installed on Triple Axle Trailer