mk1-forum.net

Hello all,

As a follow on to my overheating problems I have been doing a bit of reading up on the electrical side so here's my questions on my 64 SDL.

Would a knackered voltage stabiliser cause the water temperature gauge to show an incorrect reading?

Is there a simple way to test a water temp gauge, or the voltage stabiliser?

Can you repair a water temp gauge (trying to keep originality not being tight)?

Will fitting an aftermarket sender unit cause problems with the original temp gauge?

Cheers in advance

Sully

Take the wire off the sender and touch it to a ground point on the block. If the temp gauge goes off scale the voltage regulator is OK and the gauge is working fine.

A voltage stabilizer can fail or go out of calibration and that will affect both the fuel gauge and a Smiths electrical temp gauge.

There are solid-state voltage stabilizers available and you may want to buy one for calibration purposes. I understand you may not want one as you want to maintain originality.

No, you should not use anything but a Smiths sending unit with your Smiths gauge. It will not cause a failure or anything. However, the gauge is/was calibrated to only read accurately with a particular sending unit. The gauge may work but will not be accurate when used with a different brand of sending unit.

See the bottom of the two web pages below. They are not for the Mini but do discuss some of the steps relative to gauge calibration.
http://www.jensenhealey.com/forums/view_topic.php?id=14
http://www.chicagolandmgclub.com/techti ... e_cal.html

So when was the voltage stabiliser introduced? My late 63 must be reasonably close to your "64" and its gauges run on 12 V (or at least did).

When I replaced my original fuel tank I had to get a new fuel gauge as well. Took me a little while (slow... moi??) to realise that while the fuel gauge wanted 10V the temp gauge didn't. Its no big deal organising a second feed...

There's a guy here in Oz who packages a modern electronic stabiliser into the old metal cans.

Cheers, Ian

LarryLebel wrote:Take the wire off the sender and touch it to a ground point on the block. If the temp gauge goes off scale the voltage regulator is OK and the gauge is working fine.

Larry

The gauge is working although it's going up to H when the engine ithermostat is not open and the rad is still cold, I have changed the sender.

Sully

dklawson wrote:A voltage stabilizer can fail or go out of calibration and that will affect both the fuel gauge and a Smiths electrical temp gauge.

There are solid-state voltage stabilizers available and you may want to buy one for calibration purposes. I understand you may not want one as you want to maintain originality.

No, you should not use anything but a Smiths sending unit with your Smiths gauge. It will not cause a failure or anything. However, the gauge is/was calibrated to only read accurately with a particular sending unit. The gauge may work but will not be accurate when used with a different brand of sending unit.

See the bottom of the two web pages below. They are not for the Mini but do discuss some of the steps relative to gauge calibration.
http://www.jensenhealey.com/forums/view_topic.php?id=1
http://www.chicagolandmgclub.com/techti ... e_cal.html

Good link, thank you. So I'm looking at 60ohms between the connectors, I might rig up a few battery's in circuit to try and creat 7.5v to confirm its nt working. The fuel gauge swems to be working fine so is a good indication the voltage stabilator is working ok, I'm presuming they are on the same circuit.

The changing of the biometric strip might also be a solution I shall take one apart to investigate.

Sully

Sully2908 wrote: The fuel gauge swems to be working fine so is a good indication the voltage stabilator is working ok, I'm presuming they are on the same circuit.

The changing of the biometric strip might also be a solution I shall take one apart to investigate.
Sully

Yes, both the fuel gauge and electric temperature gauge will be supplied by light green wires coming from the voltage stabilizer's "I" terminal. If the fuel gauge seems to be working OK, that suggests the temperature gauge should be getting the "right" voltage.

Biometric strip? I believe you mean bimetallic. (And I don't use emoticons !)

The transition with the gauge system happened sometime mid- to late-1964. My late June '64 car came with the magnetic 12V gauges and the bolt-on fuel sending unit. People I know with '65s had the stabilizer and related gauges. At the moment my car has the later gauges and an added stabilizer. It's what I could find 15 years ago when I was getting the car back on the road. It is an easy change but does require a bunch of different components.

I have this Smiths test unit that tests the voltage stabiliser output voltage and also tests the instruments through their full range enabling easy identification of the fault. My temperature gauge was going haywire and I've managed to rule out instrument and stabiliser quickly, new sender required. I know it doesn't help much but for future reference you might be able to pick one up somewhere.

The volts stabiliser works like a flasher unit - 12v on and off to get an average of 10 volts. Thats why the gauges are heavily damped so that you don't see the ons and offs. Hence when you turn the car on it takes half a minute or so to get to the reading.

On pre 63 instabilised cars, the fuel and temp gauges jump immedeately to their reading when you turn the car on.

dklawson wrote:

Sully2908 wrote: The fuel gauge swems to be working fine so is a good indication the voltage stabilator is working ok, I'm presuming they are on the same circuit.

The changing of the biometric strip might also be a solution I shall take one apart to investigate.
Sully

Yes, both the fuel gauge and electric temperature gauge will be supplied by light green wires coming from the voltage stabilizer's "I" terminal. If the fuel gauge seems to be working OK, that suggests the temperature gauge should be getting the "right" voltage.

Biometric strip? I believe you mean bimetallic. (And I don't use emoticons !)

The transition with the gauge system happened sometime mid- to late-1964. My late June '64 car came with the magnetic 12V gauges and the bolt-on fuel sending unit. People I know with '65s had the stabilizer and related gauges. At the moment my car has the later gauges and an added stabilizer. It's what I could find 15 years ago when I was getting the car back on the road. It is an easy change but does require a bunch of different components.

I did mean bimetallic. No idea why I wrote that. I think I will just get a OEM thermostat and save the pain.

Sully