Ohms on a 71 FJ40 Fuel Sender (1 Viewer)

[LVilleFJ40]

Bought a new one from cool cruisers. Trying to get it to work with an Autometer Ultra Lite II fuel gauge. Don't know what the ohms are supposed to read on the sender. There are jumping around all over the place. When hooked up to gauge the gauge will read full and empty, no in between. Any help would be great.

 

[PhilC64]

Did you get an OEM style fuel sender or a universal style?

Your OEM sender should be reading 120 ohms empty, 17 ohms full. The aftermarket gauge reads 240 Ohms empty, 33 Ohms full.

Did you get a new universal fuel sender to go with the aftermarket gauge? The newer gauges will not be able to read your OEM fuel sender.

IF you did get the universal sender, do a continuity check (ohms) between the wire post and ground. I should read somewhere between 33 Ohms and 240 Ohms. Then do a continuity check between the sender wire and ground. It should be open (infinite ohms). I had a short to ground in my fuel sender wire. I found the to be nicked where it entered the cab. Also make sure you have a good ground wire from the tank to a good body ground.

Read this link. https://forum.ih8mud.com/40-55-series-tech/256908-aftermarket-fuel-guages.html

Then if necessary buy this. Auto Meter 3262 - Auto Meter Universal Fuel Level Sending Units - summitracing.com

I just did this very same mod yesterday!