Help with instrument wiring-voltage stabilizer

[bmohan55]

Trying to finish installing my new factory harness but I can't get the instruments (fuel & water) to work. Everything else is working great. I checked my original voltage stabilizer and had power in but nothing out so I figure it was damaged in the meltdown. I got a new one from our hosts yet still nothing! Took it to the electriction at work and found that it had no continuity, our hosts were out of stock but they sent me a used one to try. It worked for about five minutes or so but later when I re-started the truck it too wasn't working. Using my test light I confirmed that I had power in but nothing out. Before I order another I'd like to confirm my wiring as maybe I'm burning them up...but no smoke was observed.

Green from the fuse box going into the Stabilizer on the "B" prong (power in confirmed with a test light)

Light green from the harness on the "I" prong (male connector) (no power out currently (no pun) as confirmed with a test light)

Light green from the harness (female connector)going into the top prong of the fuel gauge and a jumper coming off that (light green) over to the top prong of the temp gauge. Note that on page 88-1 (Instrument Panel) of the GB it doesn't show this light green jumper, it shows green to the temp gauge! The Basic circuit diagram does show a jumper so that is how I wired it.

Green-black on bottom of the fuel
Green-blue on bottom of the temp

I just discovered that I had the green-black and green-blue on the wrong gauges...would that have ruined the stabilizer?

Finally, can somone verify that my grounds are correct as the GB isn't very clear?

The top knurled nut on the instrument gauge has the following grounds going into it:
A black ground coming from the speedo
Two red-black grounds from the turn signals
Two other separate black grounds going into the harness.

Please help, I am very disgusted with this truck and myself right now!

[SafeAirOne]

Umm...let's see...where to start...

Check to make sure the wires are on the correct terminals on the stabilizer. It's been a while since I've used a mechanical stabilizer (I prefer the solid-state versions), but this post here (http://www.landyzone.co.uk/lz/f31/series-voltage-regulator-wiring-35260.html) suggests that the male connector is the input (12v in) on the stabilizer and the other, female, terminal is for the 10-ish volts out.


Light green from the harness on the "I" prong (male connector) (no power out currently (no pun) as confirmed with a test light)

The photo at the bottom of this page on how to build a solid-state regulator (http://www.britishv8.org/Articles/MGB-Voltage-Stabilizer.htm) shows the B (input) as male connectors with the output (I terminals) as females. Powering the wrong side will not allow the unit to operate correctly, I don't think. Swapping them around to test this shouldn't cause any harm. Make sure the sensors are hooked up and the engine and fuel tank+chassis are properly grounded.

The normal rule of thumb is that power supply wires have shrouded female connectors so if you disconnect the wire and let it dangle onto a part of the body/bulkhead/chassis it won't make electrical contact causing a short like an exposed male terminal would.

Also, make sure the stabilizer casing is properly grounded through the mounting screw.

[bmohan55]

Thanks, that confirms I have power and output correct. Haven't thought about other reasons for the gauges not working BUT I did check the output terminals of the stabilizer with a test light and get nothing, while the input terminal lights it up. I assume the ground is good on the speedo as the three idiot lights and the instrument light works but I'll buff up the surface just to be sure. I'm taking it in to work tomorrow to check continuity.

[SafeAirOne]

I'm not a big fan of the test light. It doesn't provide any information other than there's enough power to light a tiny light bulb. How much actual voltage do you have on the input side? Not enough and the stabilizer won't work properly, as it relies on creating enough heat in the calibrated coil to bend the reed switch to make/break contact with the output terminal. I think it's a 'normally-closed' switch though, so it should send power through till it heats up. Don't quote me on that, though.

Note that your comment about your "I" connectors being the male terminals on the stabilizer is contrary to what is shown in the pic on the web site I linked to.

[bmohan55]

on the "I" conector ("I"ndicator???) i am refering to is the wire itself that plugs into the stabilizer as a male connector, noticing that most of all the other wire connectors I have delt with were female. The output terminal on the VS is female.Your explainition in your first post as to the less likelyhood of a female causing a short (well malybe only in the upsidedown Lucus world!) made sense.

calling it quits for tonight....got the Yuengling blues!

[SafeAirOne]

Ahh...OK. I thought you were talking about the stabilizer terminals, not the wire terminals.

[Les Parker]

Here is a pic. of the donor Series III dash panel, from whence came the Voltage Stabilizer.

:)




6684

[bmohan55]

Thank you Les!