Fuel gauge repair

[the griff]

I have ordered a new 50mm fuel gauge display and the sender to go with it. Niether the dial or the sender are working, they havn't worked for at least 6 years and I suspend the problem was originally the sender but due to the the dial being stuck in the same position for so long it's probably rusted or seazed up inside.
First I am hoping the new one fits ok, the sender is a 70mm plate with 5 bolts holding it down, I just hope all the holes are all in the same place so it will just screw down, I will use the old bolts if the new ones are a different thread.
After doing a bit of reading and youtubeing I sort of understand the way the sender works by increasing and decreasing the Ohms as the float moves up and down, I am also aware that different senders use a different scale from the highest to lowest/full to empty on dial and you need to make sure the sender is the correct Ohms for the dial you are using. As I am replacing both the dial and the sender as a pair they will already be matched up but presuming the existing wire going from the dial to the sender is in good condition, will it be ok to reuse it rather than having to run another one in, it's quite awkward to run it where it would need to go or is it important that it has a new wire run in that is a certain thickness to get the exact signal/amount of Ohms sent down it.

Thanks in advance, sorry if it's a daft question, but just wanted to make sure.

 

[sharpness]

So long as the cabling is in good condition, it will be fine. Best to check the continuity of each core to assure yourself.

As you rightly say, European senders and American senders have different resistance values.
European - empty = 10 ohms , mid = 95 ohms , full = 180 ohms.
American - empty = 240 ohms , mid = 103 ohms , full = 33.5 ohms.

 

[the griff]

Thanks, I will test the wire before I use it.
That interesting, I didn't realise some were highest for full and others are highest for empty.

 

[peteK]

When I replaced mine the old sender had 6 holes and had to drill the new one to match the holes in the tank,used the old plate as template.

 

[David2452]

Standard DIN fitting is the 70mm five holes you have and likely to be what you are being supplied, the resistances or otherwise of your new kit are irrelevant as you have bought a matched pair. The only thing you may have an issue with is some modern senders are 1¼" BSP, even that is not a real problem as a DIN to 1¼" BSP is available from Aquafax.