Navman 3100 fuel flow

[james1]

Hey everyone.

Just wondering if anyone has had any problems with their Navman 3100 not providing the right readings.

What has happened is on a twin tank setup the port fuel flow and totals started to stop and then stopped altogehter with the starboard continuing. About 2 hours later the starboard started to read less flow per hour before eventually stopping altogether.

I thought that it may be a blockage in the lines but I have checked that and it is clear. I have looked at all the trouble shooting guides I can find without any further clues. The head unit itself is working as it should but just not the fuel flow data.

Any ideas.

Just as a coincidence, on the same trip, the QL trim tabs blew a fuse and gave up the ghost, still looking for the problem there as well. It looks like an earth leak there so the two may be linked although not on the same circuit.

Cheers for any ideas.

James.

[Spaniard_King]

James... can you confirm that the sender units are mounted correctly as per the installation manual??

i.e
mounted between the fuel filter and the engine

Mounted vertically with the inlet at the bottom.

both of these points are critical to sender performance.

[Stressless]

Hey everyone.

Just wondering if anyone has had any problems with their Navman 3100 not providing the right readings.

What has happened is on a twin tank setup the port fuel flow and totals started to stop and then stopped altogehter with the starboard continuing. About 2 hours later the starboard started to read less flow per hour before eventually stopping altogether.

I thought that it may be a blockage in the lines but I have checked that and it is clear. I have looked at all the trouble shooting guides I can find without any further clues. The head unit itself is working as it should but just not the fuel flow data.

Any ideas.

Just as a coincidence, on the same trip, the QL trim tabs blew a fuse and gave up the ghost, still looking for the problem there as well. It looks like an earth leak there so the two may be linked although not on the same circuit.

Cheers for any ideas.

James.

Hi James

I had major issues with mine from day one.

Check to make sure it has been installed as per the fitting instructions i.e. fuel flow pointing the correct way.

One problem was a sticky impellor in the sender unit. Had it checked and had to buy a new one (out of warranty). Still had problems with the unit, so sent all back to Navman, where a faulty LCD was found (replaced under warranty). The unit was returned and fitted, and was still faulty.

Navman sent me another sender unit foc, and finally everything worked.

The units come fairly accurately calibrated, but I decided to do my own calibration by filling the fuel tank on the trailer, doing the CalF bit, refilling the tank,adjusting the amount used, and pressing enter.

From my initial web research, some owners simply connect a tote tank to the unit and gravity feed the fuel through the sender.

You can also remove both fuel lines from the sender and VERY lighty blow into the sender and check the read-out to make sure your getting an even flow.

If all fails, remove the complete unit, as I had to twice, and sent it to Navman. There is a warranty of one year on the sender, and two years on the head.

Hope this helps

Steve

PS I am now more than happy with the accuracy of the unit

[james1]

Thanks guys.

Just to clear it up a bit, the unit has been installed for some time and was working perfectly, thats why I thought that it could only be the sender units in-line but I checked them and they were fine and everything is installed correctly. I am starting to think that there could be some sort of short that is linked to the trim tabs blowing their fuse and it is effecting the sender units but can't work out how.

Cheers.

[james1]

Finally found what appears to be the problem here and thought I would update just in case someone else ever has the same problem.

The trim tab control box (That the head unit and both tabs plug into) had developed a dead short and burnt the back of the control unit. Naturally this is what caused the trim tabs to give out.

I have installed a new control unit and all is good in that department. The thing is that although the tabs and the Navman 3100 are not directly on the same circuit, they both feed off the same fuse box and now that the tabs are up and running, there are not more problems with the fuel flow meter.

Somewhere in there there must have been enough stray power, or lack of, to upset the Navman. Now I only have to sort out the electric brakes, yehaa.