- Staff
- #21
You can always try pypassing the balance module and seeing if it will read then.
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1998 Fuel Gauge sorta working but not
- Thread starter Landon730
- Start date
Landon730
Active Member
Thats what I want to try to do. Do you know which wire goes from the balance module to the ecm that I need to hook to?
- Staff
- #23
Not off the top of my head I don't. Its normally a purple or purple with white stripe for the fuel gauge. I ordered a disk last week thats supposed to cover 98-05, when it comes in I can check it to see if it's in there.
Landon730
Active Member
Ok I do have a purple wiring at the balance module. I'll hook it to my blue/black wire and see if it reads.
Landon730
Active Member
Purple wire must be the wrong one - still bot working. If you don't mind and it has it let me know what wire is the right one. I have no idea how to test it with a volt meter or any other way to figure out which wire is the right one.
- Staff
- #26
Ok, got my disc in, and loaded onto my laptop(not a bad deal for $19.70, was supposed to cover 98-05, but I found the manuals for our trucks back to 96 in it). It says the purple with white stripe from the balance module is the wire that runs to the PCM(yours does run through the pcm). The blue with white stripe from pin A in the sender is the output. If you connect that wire to the purple with white stripe, it would be wired like a single tank model.
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- Staff
- #27
All this said, you may have a pcm problem. You can try removing the purple wire from connector 1 pin 9 at the pcm and make sure the actual guage is working. With the wire not connected to anything, turn the key on, and it should go to roughly 3 o clock, ground it and it should read empty, and 88 ohms should make it read full. If that is working, then I know 2 workarounds to get you going again. You can use the fuel gauge module from a 97 4 cylinder s-10, or speedway motors sells a fuel gauge anti slosh/adapter module that will convert your 40-250 ohm sender to the 0-90 ohm gauge.
Landon730
Active Member
Ok thank you so much I’ll get something firgured out
- Staff
- #29
I'm working on trying to figure out how to save files and images for it. It works in a virtual machine program that takes over my laptop while its running. It says it should work if you connect a single sender to the purple with white stripe wire. If it doesnt you either have a wiring issue, bad gauge, or bad pcm. I'm trying to save the diagnostic flow chart for you, but you will need a gauge simulator, or something to vary resistance and simulate the sender to do it. You need something to do 0-90 ohms for the gauge, and 40-250 ohms for the senders.
Landon730
Active Member
Ok it has to be the pcm. Has a new fuel pump and it dies the same thing as the old one. Also a new gauge cluster and I still have the same problem
- Staff
- #31
You really need to check the wiring and such before condemning the pcm. Yes, the fuel circuits do fail quite often(my new to me 99 tahoe has a bad fuel driver in the pcm), but they don't normally quit working, they notmally give the buzzing needle. Try checking the pcm to fuel gauge wire like I posted above to see if that wiring is good. Next I would unplug the balance module and see if you have 5 volts on the grey wire then see what you have on the purple with white stripe. Another thing you can try is to connect the 2 sending unit inputs at the balance module together and see if it will work(light blue and dark blue with white stripe).
Landon730
Active Member
I do have a buzzing needle sometimes. Could that point at anything? It does it very rarely
- Staff
- #33
The buzzing needle is about the only failure you see on them.
Landon730
Active Member
Ok, tomorrow afternoon I get a meter and test the wires like you mentioned and let you know what I've got.
- Staff
- #35
If you do find out your pcm is the problem, you can use one of these to fix it. After I posted about the pcm's just buzzing, but not failing, I got in my 99, and the gauge in it went NUTS! Good thing I'm doing an 0411 swap in it, but I have one of these, so I may end up using it. Its a really nice piece. You can set where you want empty, how far it goes up for full, and it gives you an output for a low fuel light.
www.speedwaymotors.com
Speedway Fuel Level Gauge Sending Unit Interface Module
Fuel level gauges are designed to work with specific sending units that vary from one automobile or gauge manufacturer to another. Some increase resistance from Empty to Full, while others decrease as the level goes up. For a builder updating their vehicle with new gauges, this presents a...
- Staff
- #36
Lets try this. It's for a 2000, but it SHOULD be the same(or very similiar).