Greetings,

I have viewed many other threads on this topic, but none of the problems are exactly like mine. Here's the deal:

The Truck: 1995 K2500 GMC Suburban 6.5l

The Problem: When I turn the key, the glow plug light does not come on, nor does the starter engage. The glow plug controller, however, clicks regularly about once per second. Dash lights also pulse with the cycling controller.

The Background: I had a battery charger connected to my battery while cranking the starter. The hard start is related to an air bubble in the fuel line. After about 10 seconds I stopped cranking so as not to burn out the starter. There was nothing to indicate a problem. However, when I tried to start again 30 seconds later, the problem described above occurred. All fuses look good. There is clearly power getting to the controller as suggested by the clicking.

The question: Why would the controller and dashboard lights engage on a regular cycle like that? What could be wrong?

 

I have read that when the batteries are disconnected,the first glow cycle is not normal.

But these things do not like being boosted,higher than cranking voltage from 2 good batteries can and does burn out glow plugs.

Your problem however sounds more like a bad battery ground or a bad battery crossover connection,the starter gets power from both batteries when all connections are good as does the ECM.

But if the crossover cable is not in good shape the drivers side battery doesn't get charged or help with cranking,it is where all power for the ECM and accessories comes from first.

 

I checked the power at the starter solenoid when the key is on. It buzzes and only shows 1.8V, while the battery is at 12.7. Does this make sense? Could this be a symptom the a bad crossover connection, or perhaps a bad ignition switch?

I guess since the glow plug relay is behaving as if the battery were disconnected, I should look for bad grounds.