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MG MGB GT V8 Factory Originals Technical - Location in Instrument Voltage stabilizer?

After finally getting annoyed at my fluctuating guages,I decided to look into the wiring and see just which line I tapped for the guages. I got the correct one (LGG) ubt have found that it has some sort of stabilizer someplace in the system.

SYMPTOMS: guages read steady for maybe 20secondsm then start cycling. Voltage meter on line shows voltage cycling from 12v to 3v continuously.

I am thinking either the stabilizer is toast or more likely the new guages from outometer do not need or want them..

Someone help me find the bloody thing!??
Larry Embrey

Held by one cross head self tapping screw up close to the wiper gear cable situated approximately between rev counter and wiper motor on the same panel thatbthe wiper motor is fastened to. It is rectangular in shape, approximately 35mm long and 15 mm wide.

That is normal for the 'stabiliser', once it starts cycling it does so about once a second. If your gauges are responding to that then either the gauges don't need a stabiliser or they need an electronic one that constantly regulates. If the former then take the light-green/green off the output terminal of the stabiliser (once you have found it!) and connect it to the green on the input terminal.
Paul Hunt

PETE: Sounds like your talking about a RHD vehicle? I am in the US so LHD, but I bet that it is still over next to the wiper motor where the turn signal relays are.

PAUL: I am guessing that the MG guages ned this cycling?? Any damage from removing it and running the MG guages without it? My new autometer guages say nothing about a regulator being needed, just says to connect to 12v+

Thanks guys

Larry Embrey

I am located in Canada and on my 74 MGB it is located on the firewall just up and towards the steering column above the hood release knob.

No damage as such to MG gauges running them without the stabiliser, but they will read high.
Paul Hunt


Autometer gauges don't need a stabilizer, as they have built-in voltage compensation. The stock MGB gauges don't have this feature, so they need the external stabilizer. If you run the MG gauges without it, they will read high, but shouldn't be damaged.

As Paul pointed out, the stabilizer switches voltage on and off, providing an "average' of 10 volts or so to the gauges. The MG gauges are too slow to respond to the on-off voltage, but autometer gauges aren't.

Connect your Autometer gauges to any convenient green wire, and you'll be ok.

Do you hang out with any TR6 owners in your area? If you do, check with them to see if one of them might have a copy of my TR250/6 Electrical repair manual. I describe the stabilzer/gauge function in it. The TR6 gauges are the same type as the MGB
Dan Masters

If you end up needing the stabilizer, check out this link for a description of the stabilizer operation...

And this link for a description on how to build a "better" one...

MRL Laman

Thanks for the info guys!!

I was already toying with the idea of splicing of just before the stabilizer and just running a line up to the new guages for short term. I think long term I will be redoing all the wiring in the car, using relays and such for each "type" of electrical item. Running lights, headlights, fans, guages, that should take allot of "heat" out of the line running in the ignition..

DAN, send me an email with info on your wiring kit again.. I can't find the old email..
Larry Embrey

Hmm, Well I'll be! My gauges have been fluctuating, I had forgotten about it, untill I read this thread. Then I remmember seeing that little box when the dash was out. Since I'm using VDO gauges, I just removed the stabilizer and spliced the wires together. Now the fluctuation is gone!

Thanks Guys
bill jacobson

We aim to please Bill!! I am "too lazy" to pull mine right now, driving the car around seems to take precedence though I can't imagine why!!? I have a single 205/60r14 tire on a stock wheel, and I am moving it around running it on all 4 corners of the car before I go out and buy a full set. So far so good!!
Larry Embrey

This thread was discussed between 12/08/2002 and 13/08/2002

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