hi folks, the grip warmers on my brother-in-laws 2000 mxz800 are not working, when i turn them on the headlight dims and the tach stops working. the thumb warmer is working fine. it has power going into the switch, when i turn them on on hit it with a test light both the high and low tabs show power no matter if the switch is in high or low. i though to find and clean the ground but cannot find it. thanks for any help you may have to offer.