Clarification and a few questions.

Discussion in '80-Series Tech' started by Ghostrider I, Oct 9, 2017.

  1. Ghostrider I

    Ghostrider I

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    I have an HDJ 80 with the 4.2 I6 turbodiesel 1HDT with a five speed. It is my understanding that this engine uses both batteries for start then reverts back to one for the rest of the electrical, correct?

    Here are my questions....

    How does the second battery remained charged, is the alternator that powerful to charge it? I haven't looked that carefully, but I do not see wiring to the alternator on one of the batteries- unless I am not looking carefully, or overlooking it.

    In terms of diesels, the only knowledge base I have, is from a Rabbit/Golf diesel, where you had to pre-glow in the winter months I am from the North originally, and it gets damn cold. This is where you pulled the glow plug knob like a choke for you neophytes, turn the ignition on, waited for the light to go out and attempt to start. What is the procedure with this engine when it is cold? I don't see any glow plug light on the binnacle.

    Electrical accessories are 12v, i.e. cigarette lighter, lights?

    If I were to hardwire in an auxiliary fuse box, which battery should I run the power line to? How about lighting? In the same vein, when working on electrical, obviously one disconnects the negative cable, but should it be done on both batteries? Stupid question, but I felt it needed asking.

    Lastly at least for now, how does it start so damn quick? I mean, an 1/8th if that turn of the key, and it is started. My Jeep's no mocking here starter spins for about half to 3/4 of a second and starts. A year and a half old battery in that and four year old starter.

    That's all currently.... PROST!
     
  2. Dork

    Dork SILVER Star

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    When the vehicle is off or running, the batteries are in parallel, so everything is running at 12v. Alternator charges both batteries in parallel like normal while running. When you turn the key, and only during ignition, the second battery is put into series for the starter, giving 24v to only the starter. It starts so quick because with the higher voltage, they could put a 4.5kw starter in there, rather than the normal 2.whatever kw starter is in other vehicles.

    Startup procedure should be to just turn the key part way forward, let that hang for a few seconds while the glow plugs (or intake heater on the hdft) warms up, then crank it. The glow plug light doesn't stay illuminated the entire time the glow is actually on as far as i know.

    On the RHD vehicles, all accessories should be run to the drivers side battery. Leave the second one alone. I know on my jdm there is actually a cover over the second battery warning about such things.
     
  3. Ghostrider I

    Ghostrider I

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    Dork, thank you for your reply. However a few clarifications....
    1. Mine is European spec'd- left hand drive, thus i disconnect the left driver's side battery negative terminal? Why aren't we supposed to disconnect the other one? 2. I don't have any glow plug light- just water in the fuel, timing belt, brake, rear fog, hazards, and other ones at least from what I know from just turning the key. I just noticed that some fuses in the engine bay are not the right amps, which I will take care of stat. I haven't really had much time to explore the nuances of this rig, with a lot of personal/business stuff going on. Once they get settled, I will have more time. In the meantime, I explore and drive it when I can.

    Dork, I failed to mention.... Happy Thanksgiving! :cheers::beer:
     
  4. Dork

    Dork SILVER Star

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    I have no idea if the European spec ones are different. I would assume that if things are wired similarly, your passenger side battery is the electronics/stuff side, and your drivers side would be the 24v battery? You actually do disconnect both negatives if working on the vehicle since the second battery is still connected to ground when the vehicle is off or running, in order to make them parallel.

    I know on mine, the alternator goes directly to the second battery and that battery has its negative connected to ground through the switchover relay. , The primary battery negative is connected directly to ground, and the positive should have all the auxiliary wiring connected to it.

    As for glow plug... My light turns on for a few seconds then goes out, but the screen is still pulling current for about 30 seconds after it goes out when the vehicle is cold. If your vehicle is in a warm climate, maybe it's been removed or disabled by previous owner?
     
  5. Ghostrider I

    Ghostrider I

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    Dork,
    My truck came from the Canary Islands originally. Could that mean there is no glow plug light and/or no glow plugs just those "heaters?" However, in the engine bay there is a glow plug relay. Granted, I do live in a temperate climate Southeastern US, could that be the reason the glow plug light doesn't kick on, since the ambient temperature has yet to go below 60 degrees fahrenheit?
     
  6. Dork

    Dork SILVER Star

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    :meh:

    My intake heater (since i have a hdft) turns on any time its a cold start of the vehicle, even if its 30c outside. If that water is arrest up to temperature, it doesn't run, so i assume it uses a thermostat in the coolant line somewhere in its circuit. As far as i know the glow plug system is the same. The hdft has no plugs, it uses an intake heater instead.
     
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