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MG MGB Technical - tank unit replacement
|I have a mgb roadster65 model, chassis number ghn3/53843.|
my sender unit is not showing the actual fuel in the tank.
when the engine is switched on, the fuel gauge goes to the half tank mark.
when the tank is filled up full , its still at the half way mark. when the engine is switched off , it goes right down.
i tried to get a new sender unit BHA4471E , but am unable to source it.
could someone advice me on what replacement i could use, or how to get around this.
To determine what is faulty, gauge or sender, earth out the live feed on the tank. The gauge should read full. If not it could be the gauge or the voltage stabilizer. If you get the same half full reading it's the sender unit.
|The gauge should be adjustable. Read this piece from Paul Hunt's web site.|
thanks will do as advised, and report back.
|It won't be the stabiliser, problems with that either cause it to not read at all or about 1/4 tank high. It's also not going to be the gauge seeing as how it drops to zero when switched off.|
It could be the sender wiper hung up in the windings. As well as *briefly* earthing the green/black wire at the tank to check that it goes up to F, also remove the green/black from the sender and see if it drops back below E. I'd expect both those to be correct, which means the only option is to remove the sender and the plastic cover over the wiper and winding and see if it is repairable.
I take it you have the type with the locking ring and not the 6 screws securing it to the tank. Try part number AHU1027. This has replaced the original (which I have as ARA966) and has a 'ceramic resistor' and plastic base. It's a generic part with three terminals, so one is left unused on the MGB - one of the outer ones. The middle one is earthed and the green/black will go to the other outer one. That also seems to come with an integral sealing ring, if you get the original metal-base type you will need a new sealing ring as well.
|have checked , the gauge is ok.|
paul . i have the sender with the 6 screws, and am unable to source a new one
|Vignes, the sender unit and gasket etc. are available from both Moss Europe|
And MGOC Spares
|The senders listed are for use with the Jaeger fuel gauge. The early screw mounted sender, for the Smiths fuel gauge, is a different part number and is listed as NLA. RAY|
|i have tried the following sources, and they do not have them.|
brown & gammons
|Try Welsh MG.|
Unfortunately the six-screw sender was used with the later gauges for less than six months of production. I would have thought that it would be possible to drill six holes round the edge of the later sender, which is just flat steel. It would need to be one of the older metal base type though, not one of the later plastic base, so you may be no better off apart from used on Ebay.
Alternatively you might be able to butcher an old later tank and weld the locking tabs onto your tank ... with suitable precautions!
But at the end of the day the later tank and sender might be the only rear option, that screws up to the boot floor so relatively easy to drill the floor for that.
|Vignes, I just found this on ebay|
Early MGB '62-Sept '64 Fuel Tank Sender w/DUAL Brushes.
It has 11 hours to go and it looks like they have 7 available, so it may be worth contacting the seller if the offer ends before you get to look at it, providing it is suitable for your car.
|62 to 64 is for Jaeger instruments. The sender changed for the Smiths instruments but still used fixing screws, but only for a few months before it changed again to the locking ring. It seems that Vignes needs the one that was used for just that short period.|
|Hi Vignes - are you still searching for a solution?|
I have become aware of someone with the same tank and gauge system as you who had to use the earlier Jaeger sender, which of course reverses how the gauge operates. He was able to correct that with an electronic module, which also has facilities to calibrate the reading. The manufacturer makes two types, and says either should be suitable:
| Thanks Paul, i will contact the manufacturer for the fuel sender. thanks a million.|
This thread was discussed between 27/05/2015 and 14/12/2015
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