14V Glow Plugs on a 1HD-T - Wiring Questions (1 Viewer)

[MUDZLLA]

So my Superglow 6V glowplug controller on my HDJ-81 no longer seems to work and I am replacing it with a manually activated 12V system using the existing main relay and a momentary (wilson) switch. When I measure the resistance across the 14V glowplugs I get about 0.5 Ohms which correspond to about 25A per plug at 12.7 V (Ohm's Law). So 150A total current draw but assuming there is other resistance in the system I'm guessing I should realistically see about 80-120A. Wire sizing charts give me about 4 or 8 ga wire BUT... it's momentary (5-25 sec) so do I need this size wire or can I get by with 10ga?

Second question. Is the glow plug relay on the 1991 HDJ-81 suitable or does it introduce an unwanted voltage drop? I know the Super glow controller which uses a timer to switch to 6V is inside the cab so I assume the relay under the hood is just a simple relay??. (UPDATE: Relay No.2 under the hood does not have a resistor on the output so the only wiring mod is to supply IGN power to the B-R wire on the coil side through the new switch)

Third question: is copper-based thread compound suitable for glowplugs?

Anyone have any experience installing a manual system in these trucks?

 

[MUDZLLA]

UPDATE: To my surprise the JDM HDJ-81 actually has an 11V fixed delay glow plug system, not the 6V Super glowplug system. However it still needs a functioning glowplug timer to work so going with the 14V glowplugs and a wilson switch simplifies things, puts the driver in control and is more or less bulletproof if not totally infallible.

I think if you have a diesel 80 without the dual battery setup it would have the Super Glowplug system to reduce battery drawdown on startup.