• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

electrical problems

Share this page

14.3 is fine for voltage when the engine is running high rpms or whatever. If it gets to 15 then I would worry. I don't think there is anything wrong with your regulator. If you were not regulating then it would get much higher than that. Even though it talks about voltage, what really works most electrical gauges is current. The current might change a little with that voltage rise but not enough to really matter that much. The inside of your gauge contains 3 coils and its going to take more than a spike to damage any of them. Spikes are known to damage solid state electronics but not inductive type coils, they are much more forgiving of such things. Even if a sender went totally bad and shorted to the ground of the tank, all that should happen is it would read empty all the time, not burn up the gauge inside. That is the way they are made so the sender doesn't get hot inside your tank.
 
I am setting up to do a check of Drew's gauge and sender real soon. Maybe this weekend depending on things. I checked out Jack's gauges using resistors simulating the sender and for empty it is shorted to ground on the tank lead on the gauge. I'm still not seeing how the gauge was damaged, unless it was hooked up backwards for a long time or something. Did you do a + earth conversion or anything that might affect it?
 
healeyboz said:
should the lights be getting brighter when the motor is reved up?
Click to expand...
That depends on the battery condition and all. They might get a bit brighter when reved because the voltage is going up. Tell me the history of your electrical system, what type of generator/alternator? If it is a stock gen, then it might fluctuate quite a bit, especially with the old style regulator.
 
With the original gen and the original points type regulator, I would not be surprised to see the voltage increase that much with a rev. Before I converted mine, my lights would dim quite a bit at a red light and then brighten on take off. This was due to a not so great battery that would fade pretty quickly at an idle when the car was taking more power than the gen could produce with the lights and all on. You should be able to remove a battery lead with the engine running and then meter the output of the gen and it should still only go to about 14.5 or so and then no higher. If it goes higher then I would say you have regulator issues, but if not, its probably fine. There is a regulator ajustement you can make to bring the peak voltage level down, but I would not do that unless I was absolutely sure that I knew what I was doing there. If you get that regulator set wrong, you can have all sorts of problems. (Trust me on this, when I was young and dumb, I burnt up a brand new rebuilt gen on a mini doing this).
 
Okay,
Back to square one. I am going to drop the tank and test the sending unit again. Run an independent ground to the sender and test. I guess we will go from there. Grrr frustrating.
 
Ok, I been thinking this over. This will be a way to positively eliminate the electical system voltage as a problem. Do as I have done in the past to check gauges and other low current draw 12v devices. Go to you local Home Depot or other place and buy two 6v lantern batteries for about 2.99 a piece. Hook these in series with a jumper wire (one of the + to one of the - and you will then have a steady 12 volt supply. Use the empty + as your +12v and the empty - on the other battery as ground and then you can use these to power the gauge with the main battery unhooked. Just hook the - to the car ground wiring somewhere and the + to the gauge hot. This provides a clean power source and is what I like to use so I can work inside without much hassle. I agree with the new sender wire and extra ground for the sender, that is what I am going to fix up for Drew to use on his when I send it back.
 
Okay,
This is what I am currently thinking.... I appologize for the rambling but this helps me think through issues that I am learning.

1. I have an original sending unit coming from Tony. I will have to check it all out and see how different it really is on the inside for myself and take ohm measurements. I will probably see about rebuilding it like new and using it if it works better and or is more accurate.

2. I have put together notes from all of the conversations we have had and I have had with others over the last few weeks. It is unbelievable that the gauge could be blown by an issue coming from the sending unit.
I am having another issue with ignition. It has only happened twice, and recently. I wonder if this is connected somehow? I turned on the ignition to check a few things without pulling the starter cable. When I turned off the key, the starter was bumped by an electrical current somehow. How is this possible? Is something shorting to ground? That would blow fuses. Is there something that is shorting to ground that is not fused? Is the ignition bad? Can that even be a possible explanation for my problem(s).

Plans for this weekend:
1. Check wires on the back of the ignition to make sure that everything is hooked to where is should be and not touching anything that it is not supposed to be touching.
I think that I need to fix this issue before continuing with the fuel gauge. But if it is intermittent, how will I know that the issue is fixed?

Again,
SOrry for the rambling.
 
Re the starter: Do you have the original bugeye setup, or did you install a starting solenoid? If you have the original, with the pull switch, no solenoid, there is no way the starter could respond to the ignition key. Probably there was some fuel left in a cylinder, the engine was in just the right position, and turning off the ignition caused the right plug to fire.

This happened occasionally on my old TR4A, back in the 60s. A couple of times it even started when I just turned on the ignition, without using the starter at all!

One more thought on your gauge: are you sure it's BURNED out, not just a broken wire? I can't see any way to fry it unless the connections were reversed, and maybe not even then. That "spike through the ground" explanation doesn't sound valid to me.
 
Hmmm. The gauge was indeed bad. We checked it and so did Nisonger. Any ideas Steve? I can't imagine that it was anything other than the gauge having a flaw in the first refurbishing, but I just don't know. I wish I could solve the issue. I got the gauge back today and will not install it until the issue is resolved.
 
healeyboz said:
Hmmm. The gauge was indeed bad. We checked it and so did Nisonger. Any ideas Steve? I can't imagine that it was anything other than the gauge having a flaw in the first refurbishing, but I just don't know. I wish I could solve the issue. I got the gauge back today and will not install it until the issue is resolved.
Click to expand...
I am sending you a PM.
 
By the number on the face of the gauge
Bugeye = FG 2530/31
Mk-II = FG 2530/64
Midget Mk-I = FG 2530/63

All the above will work with a bugeye sending unit.

Mk-III = FG 2530/70
Mk-IV and on = No Number

These will only work with the latter correct sending unit
 
Back
Top