RTV 900 XT cold start issues

Unit has 400+ hrs. on it. Recently started having cold start issues, i.e. appears that the glow plugs are not heating. Dealer states there is a relay for the glow plugs but after that they want to see the unit. Kubota online parts list shows 3 relays labeled: RELAY (# K7561-62310); RELAY,STARTER (#K7561-62410) and TIMER, Key stop #T0070-31410) (not a relay?). Tried to narrow it down by disconnecting the relay(s) one at a time & checking the glow plug light but the light stays on w/the relays disconnected. When I can find a helper I'll check voltage at the glow plugs (I assume they are 12v). So, can anyone confirm that I'm on the right track?
Thanks in advance!

RTV 900 XT cold start issues