Bobcat A8705 (87-05) Fault Code: ACD/RACD Output “H” Short to Battery
Also shown on the panel as 87-05 · Also called ACD Output ‘H’ Short to Battery, ACD/RACD Output “H” Short to Battery
ACD/RACD Output “H” Short to Battery · ai-assisted, editor-reviewed · Last updated 2026-07-13
TL;DR
Bobcat code A8705 (panel form 87-05) sets when the ACD/RACD controller detects voltage on output "H" (controller pin J1 B-6) when that output isn't commanded on. Once the code sets, output "H" is disabled until the fault is fixed and power is cycled.
Medium severity. Output "H" is disabled as soon as the code sets, so whatever attachment function or solenoid runs on that output will stop working. This isn't an engine-damage or safety-shutdown event by itself, but if output "H" controls an attachment function you rely on for a job, you'll want to diagnose it before continuing that work.
What does Bobcat error code A8705 mean?
ACD and RACD stand for the attachment control systems on these Bobcat loaders and excavators that let the machine run powered attachments through dedicated controller outputs. Output "H" is one of those outputs, tied to controller pin J1 B-6, and it's normally only energized when the controller commands it on for a specific attachment function.
Code A8705 means the controller is seeing voltage on that output circuit at a time when it did not tell the circuit to turn on. The most common reason for that is a short to battery voltage somewhere in the wiring or solenoid for output "H", which back-feeds voltage into the circuit even when the controller has it off.
As a protective measure, the controller disables output "H" once this code is active. That means any attachment function wired to output "H" will not work until the short is found and cleared.
Common causes of A8705
- Output "H" wiring, controller pin J1 B-6, shorted to battery voltage
- Faulty output "H" solenoid
- Faulty ACD/RACD controller
- Moisture, corrosion, or pushed-back pins in the ACD/RACD controller connectors, mainframe harness, attachment control harness, or the output "H" solenoid connector
- Intermittent fault: loose connections, corrosion, pushed-back pins, the controller, the wire harness, or a combination of these, which may not be found if the code isn't active at the time of testing
How to troubleshoot Bobcat A8705: first checks
- With the key switch / run-enter position on, check for the active code and confirm output "H" is disabled before doing further work
- Inspect the output "H" solenoid and its wiring for signs of a short to battery, including chafed or pinched wires that could be touching a hot circuit
- Open up the ACD/RACD controller connectors, the mainframe harness, and the attachment control harness connectors and look for moisture, corrosion, or pins that have pushed back out of their sockets
- Check pin J1 B-6 at the controller connector directly for unexpected voltage with output "H" not commanded on
- If the code isn't currently active, wiggle-test harness connectors and the solenoid connector while watching for the code to reset, since intermittent shorts from loose connections or corrosion may only show up under movement or vibration
- If wiring, solenoid, and connectors all check out, suspect the ACD/RACD controller itself
How the code clears
No separate clearing procedure beyond cycling power is listed. Once the short is repaired, cycle the key switch off and back on to clear the code.
Affected models and serial ranges
A8705 appears in our records across 20 Bobcat models. Match your machine by model and serial number.
| Model | Serial ranges |
|---|---|
| E35 | SN A93K110001-99999, SN AC2P11001-99999 |
| E42 | SN AG3411001-99999 |
| E45 | SN AG3G11001-99999, SN AHHC11001-99999 |
| E55 | SN ARWM11001-99999, SN ASW311001-99999 |
| S510 | SN A3NJ11001-99999, SN A3NK11001-99999, SN ATZC11001-99999 |
| S530 | SN A7TV11001-99999, SN ATZD11001-99999 |
| S550 | SN A3NK11001-A3NL99999, SN A3NM11001-99999 |
| S570 | SN A7U711001-799999, SN A7U811001-899999 |
| S590 | SN ANMN11001-99999, SN ANMP11001-99999 |
| S630 | SN A3NT10001-12369, SN A3NT12370-99999, SN A3NU11001-11111, SN A3NU11112-99999 |
| S650 | SN A3NV11001-13098, SN A3NV13099-99999, SN A3NW11001-11248, SN A3NW11249-99999 |
| S750 | SN A3P211001-299999 |
| S770 | SN A39511001-99999, SN A3P411001-99999 |
| T550 | SN A7UJ11001-AJZV12276 |
| T590 | SN ALJU11001-999999, SN B37811001-999999, SN B3Z711001-999999 |
| T630 | SN A7PU11001-11663, SN A7PU11664-99999 |
| T650 | SN A3P012214-099999, SN A3P111242-199999 |
| T750 | SN ANKA11001-A99999 |
| T770 | SN A3P811001-899999, SN A3P911001-999999 |
| T870 | SN A3PG11001-99999 |
Frequently asked questions
What does Bobcat fault code A8705 mean?
It means the ACD/RACD controller detected voltage on output "H" (controller pin J1 B-6) when that output wasn't commanded on, most often because of a short to battery somewhere in that circuit. The controller disables output "H" when this happens.
What is the panel display number for A8705?
The numeric panel form is 87-05.
Will my attachment stop working with this code?
Yes. Once A8705 sets, output "H" is disabled, so any attachment function that relies on that output will not operate until the fault is repaired.
How do I clear code A8705 after repair?
Cycle the key switch power off and back on. No other reset step is listed for this code.
Which Bobcat machines can show code A8705?
It applies to models including the E35, E42, E45, E55, S510, S530, S550, S570, S590, S630, S650, S750, S770, T550, T590, T630, T650, T750, and T770, and T870, all of which use an ACD or RACD attachment control system.
Why does my A8705 code come and go?
Intermittent shorts are often caused by loose connections, corrosion, or pins that have pushed back in a connector. If the code isn't active when you test, the exact cause may not show up until the fault happens again.
Is A8705 a safety-critical fault?
It's not tied to engine or structural safety systems directly, but it disables an attachment output, so it should be diagnosed before relying on that attachment function again.