glow plug/controller question

[badaceds650]

so my truck about 4 weeks ago burned out 2 plugs one day so i replaced them then about 2 weeks later it burned out another so i replaced that then about a week ago it acted like another was bad so i just decided to buy all 8 new so i installed them today and I'm still getting a very short burn time then the clicking so I'm wondering if the controller is bad or what any suggestions would be great

here's what I've checked all 8 new beru's do indeed work the connections on gp controller are clean and tight

if the controller is bad I'm thinking I'll just install a regular relay and go push button what do you think

 

[badaceds650]

bump

 

[Jbevs]

goofyexponent has a good drawing he made of of the wiring in the controller. I think you should check ALL connections before ruling anything out.