Fuel gauge not working mk2 dash vr6 pump & wiring

Hi guys a minor issue really but since I've put all my dash back in I've noticed the fuel gauge doesn't move /work

Before the conversion the fuel gauge worked perfect

I used mk3 vr6 tank and wiring loom for mk3 which plugged straight into my fusebox in position M

The pump works fine

Not sure what I can do to make it work ?

 

Not much help but I've done the same thing, never reads quite right tho. Have you tried bridging the two smaller wires together? I think that might make it read full?

 

I jumped the wires as per rj and the gauge goes to full what now as the gauge still doesn't read any fuel once wires are disconnected

 

If your wiring is ok my guess would be the fragile spring that is also an electrical connection to/from the moving part of the sender has broken. You will need to check for an open circuit between the two middle pins on the pump. The pump that came with my Mk3 tank had this problem.

 

So when I take pump out you say there's a little spring in looking for ?

Have you got a pic so I'm not doing it blind please

If the spring has broken can I just replace the spring ?

 

I removed the fuel pick up and the wires looked intact

So I checked the continuity on the connections between the sender and where the plug connects

I have continuity between both sender connections

What could be my issue now ?

 

Did you remove the loom plug first? If yes can you take a resistance readings from the middle two pins? Ideally with the tank at different levels.

 

Yes I removed the plug on top of the fuel pump in the boot

So if I measure the resistance between the 2 pins what should it be ?

 

I've got a few readings on the resistance measurement on the multimeter depending on what setting on the multimeter I have

Here's the pics









Not sure if they are correct or not or what they should be

 

For some reason I cannot find my post on the comparative values of Mk2/Mk3 sender resistance with site search or external site search so off the top of my the head around 300ohms is empty 32ohms is full and if you have over a 1/4 of fuel I would say the 100 is correct. 189 is the reserve of 7 litres, 3 less than the Mk2 sender.

 

So what could be my problem then ?

 

Not entirely sure, but I would look into the Mk3 sender loom as most tank conversions including my own have used the Mk2 loom except in the boot where a short section of Mk3 power wires are used.

 

Check resitance on the plug of sender and move the float up and down to see if the value changes.

 

when i put a mk3 tank in my Non Gti mk2, my fuel gauge didnt work, the pinout on the mk3 tank is different and i had to switch one wire at the fusebox end.
cant remember exactly which now but hope that might help

 

I've still got the mk2 loom in the car just incase

So if I was to plug the mk2 plug back into the fusebox and cut off the plug on fuel pump end

What wires from my original mk2 loom do I join to the mk3 loom ?

 

I don't know but i had this saved from when i did mine, thanks to RJ's wiring info

90-92 MK2 Golf, CE2 Fusebox:

Plug M
1 - brn - GTI fuel pump earth and transfer pump pin 4
2 - red/yel- GTI fuel pump live and transfer pump pin 3
3 - vio/blk- fuel tank level sender pin 1 (sender feed)
5 - blk - cassete storage illumination
6 - brn/blu- fuel tank level sender pin 2 (sender earth)

MK3 CE2 Plug M fuel pump

1 - brn - fuel pump pin 4
2 - red/yel - fuel pump pin 1
3 - vio/blk - fuel level sender pin 3
5 - blk/wht - sunroof light switch pin 1, right front map/reading light
6 - brn/blu - fuel level sender pin 2

 

If you had a 4 pin plug on the Mk2 pump only the power wires as the sender terminals/wires can be transplanted into the Mk3 plug, but I would compare the plugs and wiring layout of both at the fuseboard end first.

 

So if I swapped the pin 2 &3 over on my mk3 loom
I take the gauge would work ?

Is pin 2&3 both power ? Because the car runs fine

 

Hmm looks like the pinout is the same at the fuseboard end of the loom then. If the Mk3 pump loom is untouched end to end I can't see why it isn't working unless it's picking up some extra resistance or is damaged somewhere along it's length.