My '85 Honda Shadow VT700C has an issue I need help with... When the key is turned on the front turn signal lights illuminate as running lights, as they should. The rear ones do not illuminate. The license plate light and rear brake/tail lights function normally. When the left and right turn signals are used the front and rear turn signal lights function properly. The TAIL LIGHT warning light on the panel seemingly illuminates randomly. Any thoughts as to what the issue could be and how to fix it? Your feedback is greatly appreciated. Thanks!