Minimum Glow Plug Voltage?

[joed]

Since the search function doesn't seem to be fully back yet, or some posts are missing:

What is the minimum voltage the glow plugs should be receiving from the controller (relay)? I measure about 12.6 volts on the "hot" side of the glow plug relay, but only 11.3 on the "feed" side to the plug banks. Should there be a voltage drop? The relay seems to cycle fine.

The reason I ask is because lately I'm having intermittent warm starting issues (less glow time) in that sometimes it takes a few seconds of cranking before it fires up. Cold starts seem to be fine (although it's not that cold here yet).

Thanks in advance. Joe.

[ucdavis]

I go from 12.6/0 on the hot/glow side w/key off to 12.6/10.7 during glow cycle (good batteries). All that resistance heat takes a buncha juice. You may have a coupla non-functioning plugs.
Or warm start problems might be somehting else. Failing lift pump, injection pump/fsd issues, vacuum restriction in fuel cap..etc.
Start w/check of glow plugs & replace if suspect or old (that's cheap & easy except for the contortion on a coupla cylinders; 3/8" deep socket), then check codes & repost findings if you need MORE BrainPOWER.