Normal Temp and Voltage Stabilizer

[MikeH]

Hi All, What number does the N on the temperature gauge represent, 180? Also, where the heck is the voltage stabilizer in my 71 MGB? Thanks, Mike

71 MGB OD & Wires
63 TR4 Surrey Top

 

[PAUL161]

Mike, Look on the fire wall above the clutch pedal. It's held on with one screw and should have three wires going to it. I'm not sure what the temp numbers are at Normal on the gauge. PJ

 

[jlaird]

Not sure about temp gage either. However, my new sprite, back when in Hawaii, always ran in the 180 range except for the big passes, then it would go up 10 degrees or so, if that helps any at all.

Might want to fit a gage with real numbers under the dash for awile and see whats really happening. Just tape it under there.

At one time I ran an oil temp gage with the sender in the oil drain hole, worked fine.

 

[wkilleffer]

I've had to deal with the stabilizer. It's a very small rectangular box mounted high on the firewall behind the tach. It has three terminals, one of which will be for input and the other two are outputs to the gauges.

As far as temp goes, I use a 190 thermostat, and my gauge typically goes up to just to the right of center, obscuring the right side of the N. Sometimes it allows to whole N to be seen, but doesn't get hotter. Before I got the stabilizer to work, it would go all the way to H.

 

[dklawson]

On the Smiths 90 angular degrees of sweep gauges where "N" is straight down (or up on some later Triumphs and Jags)this corresponds to about 185oF. Keep in mind that variations between voltage stabilizers, sending units, and gauge calibrations make this "relative". Don't count on it being any more accurate than about +/- 5 degrees.

 

[David_DuBois]

Mike - Use some zip cord (power cord for lamps) and make up an extension for the wire going to the temperature sensor and for ground, then remove the sensor from the head, hook it up to the extension cord and place it in a pan of water on a camp stove next to the car. Stick a thermometer in the water and heat the whole mess up. Note the temperature when the gauge reads mid scale, or better note the gauge reading at 180°, 190° and 212°. Cheers - Dave

 

[PAUL161]

There has been a lot of discussions about the voltage stabilizer on our cars. I being the courious type, took one apart just to see what made it tic. I works by using a bi metal strip which senses voltage change in the control wire. Thus opening and closing a set of points. The points will get dirty and also burn to the point that they will stick or make no contact at all. A new sensor is fairly cheap to buy. Buy a new one from Moss or whoever and replace it. Throw the old one in the trash. Now that you have the voltage corrected, look elseware if you still have a problem. I went through the same thing and a new senser solved my problem. PJ /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/thumbsup.gif

 

[Mickey Richaud]

Better still, if you're handy with a soldering iron, you can convert to a solid state 10V voltage stabilizer in the form of a single regulator from Texas Instruments and others. This was covered in a thread a while back:

https://www.britishcarforum.com/ubbthreads/showflat.php/Cat/0/Number/122708

I did, and the gauges are rock-steady now.

Mickey

 

[danmas]

[ QUOTE ]
... you can convert to a solid state 10V voltage stabilizer...

[/ QUOTE ]

You can do this, and it'll work OK, but you'll be giving up a bit of accuracy if you do. The problem with the solid state regulators is that they are temperature compensated; the stock regulators are NOT. Temperature compensation sounds like a good thing untill you realize that the gauges themselves are not compensated. When the gauges are cold, it takes more voltage to operate them. When it is cold, the regulator provides more voltage, exactly in proportion to the extra voltage needed by the gauges. Both devices are of a thermal/bi-metallic strip construction, so temperature changes effect each in a complementary manner.

 

[Mickey Richaud]

Thanks, Dan - didn't realize that temperature would affect this. Is it only cold weather? We rarely take the B out when it's below freezing.

Mickey