72 Blazer K5 Fuel Gage Stuck On Empty.

[Artiep92]

Recently been having a fuel gage problem. The gage was reading past full at the 3 o clock position.
Just bought a new gas tank and sending unit. Installed it
Last night. Put 5 gallons of gas in the tank and now it is Stuck on E and not reading at all.
Anybody have any ideas of what's going on.
Thanks.

[swyfor5]

Recheck the ground wire.

[Artiep92]

Checked the ground and it's good. Drove it around today and the fuel gauge is Stuck at 3 o clock again. Now I'm back in the same boat I was before. Anyone know what the problem cold be?
HELP!!

[GhostTown]

I know you said you checked the ground, but after new SU and tank... it's likely the ground.

[72blaz]

If it's grounded correctly.. it might be your fuel sending unit..probably need a new one....but it's usually related to the ground almost 95% of the time.

[Artiep92]

Can the sending unit possibly be bad if it's brand new? Will check the ground again.

[Artiep92]

Drove the car around last night. And the needle went back to E. It has gas in it. Think it could be the gas gauge itself?

[72blaz]

at this point it sounds possesed...I think your gonna need to get a priest involved.

[TBONE1964]

Originally Posted by Artiep92

Can the sending unit possibly be bad if it's brand new? Will check the ground again.

Yes it is possible to get bad parts right out of the box brand new. It does happen but to me it sounds like you have connection issues.

How much gas to you think is in the tank now? It should read about 1/4 tank with 5 gallons. If you turn the ignition to the run position, reach up behind the cluster and wiggle the connector where it plugs in to the circuit board and watch the gauge to see if it moves around or not.

You also have 2 grounds to be concerned with. The sending unit needs to have a good ground to the frame. There is also ground on the gauge that comes from the connector that plugs into the circuit board. The ground wire is black and is located in pin number 7 of the connector (if you have a full gauge cluster) On the back of the gauge there are 3 studs. One one the left (looking at the front of the gauge) is power from ignition, the one one the right is from the sender (not the ground, should be a tan wire) and the middle lower one is ground. You can use the lower middle stud and try a temporary ground there and see what happens.


Keep use posted.
Tom

[red71cheyenne]

Had the same problem when I put my new sending unit in, turned out the fuse in the fuse block had blown and it only affected the gas guage. Check the fuse.

[terryggoround]

I am having the same issue with my 70 jimmy. the ground coming off the sending unit was iffy at best. After cleaning and a little sanding I had a good ground. The gas gauge still didn't move from the 1/4 postion. Checked the fuse box and there was no fuse but instead had 2 blade plugs. I switched the plugs then the tank read a little past full and didn't move. Had it in the shop and the shop removed the tank and told me that they ordered a new sending unit and was just waiting to get it. A week later the shop tells me they tested the sending unit and it worked so they put it back in the tank before talking to me and of course the gauge still doesn't work. Now I can check the ground off the gauge and see if that is problem. Thanks for the info.

[Moreyel]

Artie, all these suggestions are correct. I had the same problem. Found the test threads and did most of them. I did replace the sending unit because it wasn't quite to specs and old and the new one has the plastic float. Turns out that when I clipped on another ground, it started working right! I fixed the two factory grounds and it's done.