Aprilia fuel gauge

[peterblenk]

Does anyone have drawings, sketches, or photos to show how the sender mechanism goes together? Also, is there a source for parts - especially the large Mazak piece? The two I have are crumbling and also warped.
peterblenk@aol.com

[GeoffJohnson]

Hi Peter
Here is a sketch I did of the fuel gauge sender that I did some time ago to remind me how it worked.
Hope it helps

Geoff Johnson

[Mikenoangelo]

Blimey that's even worse than the one on the Augusta!

Mike

[davidwheeler]

Thanks, Geoff, I have posted it on the technical information thread.

[peterblenk]

Thank you, Geoff; this is very helpful. I am told that
someone, perhaps in Switzerland, made new ones. Any idea who that could be? I was thinking that it might be possible to scan and 3-D print the offending Mazak part in a better material, such as aluminium. Peter

[williamcorke]

I'm resuscitating this topic to (as far as possible) keep Aprilia fuel gauge/sender info in one place on the forum.

My car has the early round instrument, but I believe the ALIT sender unit is the same for the later rectangular gauge.

The restoration of my system - at both ends of the car - has progressed to the point where there are now just 2 unsolved problems.

1. The sender is missing the 'rotating spring contact' show in Geoff Johnson's very useful diagram in this thread. Can someone provide a photo of a correct one? All I can find as reference is Photo 1 below, which has what looks like a homemade replacement (in steel or even aluminium?). How is the contact finger attached to the rotating barrel-shaped piece?

Incidentally, I don’t think the longer contact finger in the photo is correct - it would earth the circuit. Perhaps is a retainer for the cover not shown in the photo. Whatever, my unit doesn’t have this part.

2. I am having trouble finding replacement bulbs for the gauge. The glass on the originals is 9mm in diameter - with no 'bulge' to their shape. The replacements I've sourced from two different places are 11mm or 12mm and so won't fit into the tubes within the unit that lead to each of the indicator lights. Photo 2 below shows 3 replacements on the left and the 3 working original ones I have on the right. Does anyone know of source for these 6v bulbs, or has perhaps found an LED type that is narrow enough to fit?

[simonandjuliet]

William, a few photos and suggestions !

The bulbs were too tall, but since the tops were plastic, I cut them down to fit behind the unit

Let me know if you want more detail or dimensions for the tank unit parts (I don't think that I have a spare but I'll have a look)

BTW there is a short pin hat goes through the axle of the disk that holds it in place on the top plate. The pin is then held in place by the groove on the underside of the insulating contact "needle"

Poorly explained but if you want more detail I will try and improve my description !

[williamcorke]

Perfect, thank you Simon,

I've ordered the bulbs and the photos of the 'finger' are what I need to make a replacement, which I think could be soldered to the top of the top of the 'cap' (whose locating pin I'd already replaced).

Am I right in thinking that the finger should be on the contact for the first of the 9 light (5 litres) when the float is at the bottom of its range of travel?

[williamcorke]

Update - bulbs have arrived, slightly different shape to Simon's (Photo 1) and required no modification to fit perfectly. Now to make the 'moving finger'.  There are a few electrical bits of construction I'm going to have to get into including, if no-one can help me out from their parts stores, two of the 3 dash light brackets.

James Parry has kindly found one of the pieces I need (Photo 2) but I need another the same as this, and also the central clip-in bulb mount (Photo 3) which carries the two bulbs for the warning lights (dynamo and indicators).

If any of you can help, please let me know, otherwise I'll be testing my fiddly fabrication skills (though nothing can be worse than trafficator wiring!).