Trucking startup Harbinger is still a relatively new company, but the flexibility of its electric vehicle platform has helped it capture another customer in a different line of business. This time, Harbinger’s chassis will be used in emergency vehicles for 70-year-old company Frazer. The two companies announced Wednesday that Frazer will build ambulances on the hybrid version of Harbinger’s platform, as well as larger mobile healthcare vehicles. Frazer will also become a customer of Harbinger’s new energy storage business, which the startup debuted earlier this year in a partnership with Airstream. The deal shows that companies like Harbinger are finding success with electric and hybrid vehicles despite headwinds in the passenger vehicle space in the United States. Grounded, another startup based in Detroit, revealed this week that it worked with Colgate to develop a small fleet of mobile dental care vehicles .…