The HK(688) Booster harness with external OEM Subwoofer is designed to add an aftermarket mono amp to the OEM Booster to power the OEM sub.
Please note that harness will not work if HK (688) Booster is defective/malfunctioning. No returns/exchanges/refunds due to defective OEM amp.
Warranty of harness is one year from purchase date. Harness kit is designed for experienced DIYers. Professional install suggested. Support limited to harness install; no support given to aftermarket parts not sold with harness kit.