It has been asked several times what the ohm readings are on the fuel level sender, mostly because people wanted to use an aftermarket fuel gauge. Dave D and I both mistakenly thought it was roughly 33ohms empty, 5-10 ohms full. Both of us independently measured the sender to get these numbers.

Ohmmeters are tricky.

Trekkor used a VW Bug fuel gauge that's 75-ish ohms empty, 10-ish ohms full, and it works on his car.

I just yanked the fuel tank for cleaning, and while I had it drained, I also tested the fuel sender. There are four lugs on the sender the connector attaches to. One appears to be a locating pin, one is ground, one is the switch for the fuel light, and the last is the fuel level potentiometer. On the car, the readings kept jumping around, and I kept getting 33-ish ohms again with the tank pretty much empty, between two of the terminals. Two others showed no connection, and the other showed 0-5 ohms (jumped around), which must have been the fuel light switch.

Off the car, with the sender removed, I found that I could get 74 ohms with the ohmmeter lead on the top of two of the terminals, but jumpy readings on the sides. Cleaning these terminals with alcohol fixed that. 74 ohms empty. Flipping the sender over, so it was at the "full" setting, I got 5-ish ohms across the same sender terminals.

So, it looks like the 914 sender is, indeed, exactly the same as the VW Bug sender, so you can buy a cheap VDO gauge from a bug place and expect it to work.

Thanks for posting more data. I found that it was 74-5 ohms empty to full. I called PA or Hollywood speedo and asked them and they sold me a "caliberated" one for not much more than a regular. A 90-0 ohm will work as it is the same concept. What the speedo place did, I later figured out, was take a 90-0 ohm and drill a hole in the side where there is an obvious spot to do so. This opens the gauge up to caliberating via a pot on the inside. It only cost me $10 to have them do it so no biggie. I think all together it was $50.

The 914/6 GT used a 60mm gauge with a calibration group of 21/287. The measurements were: RES, 67 ohms, 1/2, 38.7 ohms, full, 2.2 ohms.

The stock 914 fuel gauge and sender is calibration group 21/263, which roughly corresponds to the measurements you guys have reported (74 - 5 ohms, empty to full).

I'm working with NH Speedo on a 914/6 GT style gauge made from a '67 SAAB unit that will have the flavor of the original and work with the stock 914 sender (see Armando's site for pictures of the original and repro made in Europe).

The new gauge will let me use the 911 temp/pressure gauge in place of the stock combo gauge on the left side of the cluster. I will mount the fuel gauge in the center console in place of the temp gauge.

I'll post pictures when I get it back from NH Speedo next week.

Thanks,

sort of unrelated. i got my 911 gauges out of a '74 911 S and the fuel gauge works just fine with the stock 914 sending unit ....

Andy

QUOTE (SirAndy @ Jul 22 2005, 11:18 PM)

sort of unrelated. i got my 911 gauges out of a '74 911 S and the fuel gauge works just fine with the stock 914 sending unit .... Andy

because 911's use the same fuel sender andy.....

theyre speaking of the little cockpit gauge.....

QUOTE (Aaron Cox @ Jul 22 2005, 11:20 PM)

theyre speaking of the little cockpit gauge.....

that's why i said "sort of unrelated" aaaaaaaron ...

Andy

QUOTE (SirAndy @ Jul 22 2005, 11:33 PM)

QUOTE (Aaron Cox @ Jul 22 2005, 11:20 PM) theyre speaking of the little cockpit gauge..... that's why i said "sort of unrelated" aaaaaaaron ... Andy

i cant read ahhhhhnnnnnnndy.....

Got the GT style fuel gauge back from NH Speedo today. Here's a picture. I think it really turned out great! More later. . . .

Here's what it looks like in the console. . .any comments?

Thanks,

QUOTE (type47fan @ Jul 30 2005, 10:45 PM)

Here's what it looks like in the console. . .any comments? Thanks,

looks way bitchin!

how much did that cost you??