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Wiring

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M

MGBGirl

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I hate all this wiring crap. There are way to many. I wish I could have done it and had my own organization to it. The reason why I am even having to deal with it is because we still can not get the original temp. guage to work and the fuel gauge does not give a read either. We have bought now two of the solid regulators to try and build our own and they have not helped. Should we just grit our teeth and buy a whole new regulator of might something else be the issue? The wires that I have been able to reach look clean and don't seem to not be loose, but I can't tell where one wire starts to where it ends. Also, how do you determine if the temp. guage is just bad and not working? We have opened it up and there is not much to it and it looks like it should work.
 
What is the voltage into the regulator, and what is the voltage out of the regulator?
Battery connected, key on.....
 
That's what BL needed. Girls to engineer the wiring loom.

All the wires would have pink on em :laugh:
 
Both of those dials are supplied with current through a green wire. Trace it back to the fuse panel and be sure that 12v is being supplied. Depending on the year, there is a voltage stabilizer fitted under the dash. Green wire is connected on each side. New stabilizers are solid state and should last for years to come.
Cheers,
D.
 
I hesitate to identify wires by colour, after all these years and owners, and especially after she tells us what a mess the wiring is.
For all I know, some PO or shop has a purple wire from the fuse box (maybe spliced in), and an orange wire to the gauges.

Finding voltage into the regulator and out of the regulator, for remote troubleshooting, is easier.
 
DNK said:
That's what BL needed. Girls to engineer the wiring loom.

All the wires would have pink on em :laugh:
Click to expand...

Ha, that's what my dad said, they would all be pink. But no, I would not use the same color twice and I would know where all the wires go.
 
TOC said:
I hesitate to identify wires by colour, after all these years and owners, and especially after she tells us what a mess the wiring is.
For all I know, some PO or shop has a purple wire from the fuse box (maybe spliced in), and an orange wire to the gauges.

Finding voltage into the regulator and out of the regulator, for remote troubleshooting, is easier.
Click to expand...

Its not that its a mess, there are just so many of them and I get lost in the maze of it all. You know?
 
TOC said:
What is the voltage into the regulator, and what is the voltage out of the regulator?
Battery connected, key on.....
Click to expand...

The voltage in is 12 and the voltage out on the first one was 13, I think and the one we just tried out was 11. I know it is supposed to be 10, but if its 11, would that really make that big of a difference? And yes, the key was on and battery connected.
 
Has anyone attempted at building the solid regulator and been succesful on it. Could use some tips if there are any to be had. It doesn't seem to difficult but all advice is definately appreciated (sp?).
 
um.......how did you get 12 in and 13 out?

I know on my mechanical stabilizers it's about 7.

And that 10-11-12-13V out does go to the gauges?
And do you read any voltage on the load leg of the gauge with the sender disconected?

Dave
 
If the wiring is like you stated, then it is time to re-place the harness and start from new before the vehicle goes up in smoke.
Cheers,
D.
 
I'd agree with that. Any harness that over the years has been turned into a cut and paste job will continue to give troubles no matter how many you solve since most prior owners were probably not concerned with doing it right.
 
Look for Crimp connectors and redo the connections with solder and heatshrink tubing.
Any bullet connectors especially the black ones(grounds) should be pulled apart and the ends emery clothed and put back together with a new female joiner piece and a dab of dielectric grease.
You can make your own tubes for the bullet connector center pieces if you want too and use the old rubber tubes but I just ordered a bunch of the 2 way and 4 way's and patiently started at the rear end(taillites etc) and worked my way through 1 lite at a time. Amazingly all lites,tach,fuel guage etc working good so far.
Doing that alone will solve a whole bunch of problems I'm sure.
Good luck. Mark
 
I guess I was maybe a little misleading about the wiring. It's not really a mess - just a bit overwhelming to me is all. The po did add a cruise control, and that's quite a few extra wires, but I will probably remove all that...
Ok - there is good battery voltage to the stabilizer, and the wire from the stabilizer is good to the fuel gauge, and also on to the temp gauge. When I checked the voltage from the stabilizer (the mechanical one), the digital volt meter was acting crazy, which I have read is "normal" because it is trying to read the fluctuating voltage being generated by the stab.
Sorry about my previous report of voltage measurements. The battery voltage is about 12.6. When I connect the solid state stabilizer (NTE1953), it reduces the volts to 10.9. When I connect the temp gauge to the 10.9v, the gauge still does not work. Is it maybe a coincidence that both the fuel and temp guages don't work? I was thinking not, but maybe it is...
About testing the temp guage, I don't know which is the "load leg"... is it the terminal that the sending unit wire connects to?
All I have done is measure the ohms between the 2 terminals (with the guage removed), and I get about 60. Don't know what that means, if anything. What voltage would I expect from the load leg?
 
Yes, the load leg of the gauge goes to the sender.
If the sender is disconnected, and you have the same voltage on power and load legs of the gauge, at least the gauge works electrically, if not mechanically.
Now, re-connect the temp sender and re-check the load leg on the temp gauge.
Is it still 10.9V?
If so, one of two things.
The sender is bad, or one of them infamous Lucas connectors between the gauge and the sender is unplugged or badly corroded.
If the voltage is still 10.9 on the load leg of the gauge, disconnect the temp sender and check the voltage at the plug/connecto that is part of the wiring harness.
If it's 10.9V, the sender is bad.
If it is zero, the wiring, connector or unplugged somewhere, is the cause.
 
There is 11 volts getting to the power and the load legs. We checked the wire between the guage and sender with the ohm meter, and that wire is good (after first disconnecting the wire from the sender and from the load leg terminal of the guage for the ohm test).
Earlier (on the trip from IA to MS) we used an aftermarket temp guage, wired to the original sending unit, and that guage worked (not the correct reading I'm sure, but it did work). So we're assuming the sending unit works.
Results of your test however, when the wire from the sending unit is connected back to the guage (load leg), the voltage drops from 11 to 10.8.
Dad thinks the mechanical part of the guage is just a bi-metal strip which gets heated from the electric current. When the bi-metal strip heats, it bends and causes the guage needle to move. More current causes more heating and more movement. He doesn't know how the mechanical part wouldn't be working because it is such a simple device. Could it just wear out?
 
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