I'll go out on a limb here and say it IS a SPARTAN issue.
Call the techs at Spartan directly and tell them the last six (6) digits (i think) of your VIN to identify what you have (at least when it left their factory).
Recreational Vehicle Customers Only:
Customer Service 800.543.4277 (Option 1)
7:00am - 11:00pm/7 days a week
Coach Net (Emergency Roadside Assistance): 888.890.1741
Available 24/7
Fax 517.543.9264
Service Development:
800.393.8861 (Option 6)
Service Parts:
Service Parts 800.722.3025
Shipping Information 800.722.3025 (Option #5)
Fax 888.879.5671
Recreational Vehicle Retail Customers:
Rvcustservice@spartanmotors.com
Emergency Rescue Customers Only:
Warranty Authorization - 800.543.5008 (Option 1)
Parts - 800.543.5008 (Option 2)
Billing Inquiries - 800.543.5008 (Option 3)
OEM/Selling Dealers - 800.543.5008 (Option 4)
Campaigns/Recalls - 800.543.5008 (Option 5)
Fax 517.543.9264
Service Development:
800.393.8861 (Option 6)
Service Parts:
Service Parts 800.722.3025
Shipping Information 800.722.3025 (Option #5)
Fax 888.879.5671