Is this a voltage regulator?

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Jan 3, 2014
Johannesburg, South Africa
Dear mudders.

Please help me identify this electical part. I think it might be a VR but not sure. How do I know if it still works. There is continuity between the smaller terminal points but not the larger one. In my truck there was only wires connected to the smaller ones as well but I doubt if it was wired correctly

1978 HJ45 that I am busy converting/rebuilding as a 2F

As always thanks in advance for any help

Hi there Johann

Definitely not a VR.

Some sort of relay .... Maybe "starter relay"?

lostmarbles I think you are right. If I look at the HJ45 wiring diagram it has a starter relay with 1 coil and 4 connections. So my question is seeing that I am rebuilding as a FJ45. The motor started with only two wires connected to this relay. My guess is the two wires was dead anyway like a lot of the other wires. The 2f starter has this built in so Am I right in saying this wont need to go back on the truck?
Does your 2F starter have a big "starter solenoid" on it? (I'm not familiar with 2F starters.)

(I think your old H motor would have had one on its gear-reduction starter anyway..)

The purpose of the starter relay is to prevent contact damage occurring in your ignition switch when you start cranking. This damage would be caused by the sudden inrush of current to that big solenoid (which would cause the contacts within your ignition switch to arc/burn).. And solenoids have another effect on current too. - They don't like it to stop .. so they try to keep it going by arcing electricity across the ignition switch contacts when those contacts open too...

So if your 2F has a more "car-like starter" and doesn't have a big solenoid mounted on it (that serves the dual purpose of "engaging your starter's drive cog in your flywheel ring-gear" and "closing the high-current circuit through your starter motor") then I guess it's safe to do away with your starter relay and feed that solenoid directly from your ignition switch (to get power when your key is turned to "start").


PS. The contacts inside that starter relay are designed to cope with high current surges whereas those in your ignition switch are not..
This is the best picture I have if the starter

Not sure if it helps much. I think the cone shape on top of it houses the reduction gears and a selenoid? At the back there is a spade type connector and the the battery + connection from what I can recall.

The PO was a farmer who for the past 20 years just made sure the cruisers wheels turned so I am sitting with a few issues of uncertainty regarding what goes where and completeness thereoff. [emoji1]

The cruiser ran when I bought it but the wiring was such a mess I stripped all out so trying to get my head around this selenoid thing which I thought was the VR.

The only other box type selenoid that came off the cruiser was the flasher relay so it seems I am missing the VR then....
I see your 2F starter has a much smaller solenoid than my B diesel. Here's the comparison...



And mine:


And your old H would have had a similarly large one in the same sort of cast alloy housing..

So on that basis I think you'd get away with controlling that solenoid directly off your ignition/key switch..

And I don't know why I didn't do this before ..... but looking at the wiring diagram for the FJ-series does show Toyota doing just that (ie. eliminating the starter relay and controlling the starter solenoid directly from the ignition/key).

Looking at the guts I would "guess" that it's a simple on/off or single stage VR. It's design looks like it's set to trigger at a set voltage. Still guessing I'd say when the system reaches full charge it triggers, makes contact and takes the field wire of alternator to ground through a resistor. But I'm just guessing till someone identifies it.
I have no experience with HJs or a wiring diagram for one, but couldn't that be a relay for the glowplugs of the H engine? It's no voltage regulator.

You said that the small terminal had a wire connected. Does that wire dead-end, or does it run to a timer?
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Based on the w/d from a Trollhole-provided 1975 F/B/HJ manual, it appears that it is not a glow plug relay.


However, it could be a relay for the front drive actuator. I have no personal experience with the dash actuated 4WD, though, so I can't say for sure.

Thanks all. I think it was the old starter switch. I am not sure if the wires even went somewhere as the cruiser wiring was so shot I ripped it out. The cruiser has a manual lever for the transfer case.

I am going to leave this part of with the rebuild as I cant see the point of it anymore. When I did remove the cap I noticed the small plugs probably control the lever on the coil. So the fact that nothing was plugged in on the big port that would then receive power makes me think this thing was dead on the truck even if it did somehow still received power. I need to figure out if my alternator is internally regulated next... As there definitly wasnt a VR then on the cruiser when I received it.

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