# 1993 HB SE Misreading fuel gauge and back-up light



## pedxing (Jan 2, 2008)

Have some small issues with my 1993 Hardbody SE. 

1. My back-up lights come on intermittently while in reverse. It goes into gear fine, but the lights come on only about 50% of the time. I was thinking of the back-up light switch as the least expensive place to start, can anyone tell me where it's located though? I don't have my owner's manual for this vehicle.

2. The Fuel gauge is misreading. The tank is full, but the gauge only reads 3/4 full. Do I need to drop the tank if I want to test the sending unit and/or floater or is there access somewhere?

Thanks,
Dustin


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## smj999smj (Jan 1, 2006)

A little info goes a long way.....4X2 or 4X4? Manual trans or automatic? King Cab or regular?


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## pedxing (Jan 2, 2008)

Wilco, thanks.

It's an SE-V6 4x4 5-speed manual transmission King Cab with limited slip differential and about 330,000 kilometres on the original engine. Since I bought it, I've only overhauled the front brakes and put on a new exhaust, it runs great otherwise.


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## pedxing (Jan 2, 2008)

As per the backup light... I purchased a backup light switch as it was under $20 and thought it a decent place to stab in the dark. My stop lights and signal lights work fine. I went looking at the transmission underneath to try and pinpoint the backup light switch but couldn't. There were several switches but I don't know which is which. Does anyone have this mapped? I'll try the dealership if they won't charge me otherwise.

Thanks!


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## pedxing (Jan 2, 2008)

For anyone interested, the backup light switch is on the passenger side at the front of the transmission.

Cheers,
Dustin


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## gogiburn (Dec 17, 2007)

*Guages & backup lights*

How about the temp guage? I have the same problem and it's the fuse box.If I push the right side of the box it makes contact and the backup lights and guages work.The fuel guage bounces around when I fill the tank completely but settles down after putting some miles on the truck.Still haven't figured out if it's just the fuse or the whole box.


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## Oldnissanguy (Jan 6, 2005)

I don't know if your fuel guage issue is common, but I have pretty much the same problem on my 97. Only difference is that mine will read full for about 5 to 10 miles after a fillup and then drop to 3/4. It's been consistant with two different guages so I'm guessing it's the sender. I think you have to drop the tank (that's why I'm just living with mine) but maybe someone on the forum will know another way.

BTW, I just set the trip meter every fillup and then fill up again when it get to 150 - 200 miles. I don't like for the tank to get too low and I really don't like to push trucks.


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## tacosteelerman (Jan 20, 2008)

I don't know if your problem is related but in my 88 pathy I have to turn my ignition key switch very slightly foreward or backward to get various electrical items to work Maybe sometime when your backup lights are not working play with the ignition key switch GOOD LUCK


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## Yontrop (May 14, 2004)

Instead of dropping the tank, you and a friend can remove the bed, and just do the fuel pump/sending unit from the top.


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## pedxing (Jan 2, 2008)

gogiburn

You have to push the right side of the fuse box? You mean the box itself needs to move a little to get your temp gauge and backup lights to work? I've been underneath to check for pinched wires or anything, but I can't see anything strange.

I've let go of the fuel gauge problem for now until the backup lights work. I hate backing up without letting people know. I'll try to putz with the fuse box tonight. The lights used to work intermittently, now not at all, so it may indeed be fuse related. Does the engine need to be running to test the backup lights or can I just have the key set to the on position? I suspect the engine does need to be on, so I'll need a helper. That's what kids are good for, right?

Still no luck with the backup light switch though. I bought an after market one ($20) and the wiring end doesn't fit, but the threaded end does. The existing switch has two wiring connections whereas the after market one only has one connector. It's weird. Might be the 2WD one they gave me by mistake.

Thanks


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## gogiburn (Dec 17, 2007)

*Lights*

I would think you need the trans in rverse and at least the key on the run position.As soon as the weather clears here (NJ) i'm going to pull the fuse box and see whether it's just the fuse connection or the whole box.


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## pedxing (Jan 2, 2008)

*Reverse Lamp Switch*

You're right. As long as the key was set to On, I could test the new switch and it was fine (without being threaded into the transmission). My problem is getting the old one out. It's not budging for anything. I sprayed Liquid Wrench on it but nothing, not to mention is a PITA to access. Is there something better than box wrench to get these things out? I could chop the end off the old switch and try an impact socket wrench I guess...

Thanks


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## gogiburn (Dec 17, 2007)

*Freeze off*



pedxing said:


> You're right. As long as the key was set to On, I could test the new switch and it was fine (without being threaded into the transmission). My problem is getting the old one out. It's not budging for anything. I sprayed Liquid Wrench on it but nothing, not to mention is a PITA to access. Is there something better than box wrench to get these things out? I could chop the end off the old switch and try an impact socket wrench I guess...
> 
> Thanks


Theres a new product (to me anyway) called Freeze off or something like that made by CRC and a couple of other companies.It freezes the part IE: makes it shrink breaking the bond of rust and has penetrating oil too.I'd try that first or het if you can get to it with a torch.


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## Humanure (Feb 15, 2007)

My 93 ka24e also shows about 3/4 full when the tank is topped with fuel. Someone mentioned earlier that they don't like to "push it." Well, I push it many times and notice that I can go well below the empty line and find that missing 1/4 of fuel. I thought about readjusting the needle in the instrument cluster, but with my luck, it would probably break apart in my hands. I have an old car that doesn't have a fuel gauge; it has a reserve tap. So I am happy to live with the misreading gauge in my truck.


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## pedxing (Jan 2, 2008)

*Update*

Thanks for the info. I replaced the backup light switch finally and the lights work. Do the Nissan guys have small hands and smaller wrenches or some better tool to access the switches? I haven't seen a stubby wrench that will tighten these switches easily, at least not where the reverse lamp switch is located.

Humanure, you've got bigger kahones than I do. I keep thinking I'd like to try and drive it below the 'E' just to see, but haven't done it yet. I've read that these tanks are 21.1 gallons (or 80 litres where I am), and when I fill the tank at 'E' I end up buying about 60 litres, so I suspect you're probably right and there is more fuel down in there... Does a consistent misread of the fuel guage usually indicate something is wrong with the floater or sending unit as opposed to the guage itself?

Thanks.


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## Humanure (Feb 15, 2007)

pedxing said:


> Does a consistent misread of the fuel guage usually indicate something is wrong with the floater or sending unit as opposed to the guage itself?
> 
> Thanks.


In my case, I suspect the sending unit is not located perfectly to read the actual amount in the tank. Again, I have the 4 cylinder ka24e motor so I'm not sure if we have the same setup. During one of my trips when I was seeing how far I could go below the Empty line, I accidently found that my instrument cluster has a low fuel warning light to alert me when I am running too low. Now I feel safe to go about 1/4 below the Empty line and fill up then.


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## gogiburn (Dec 17, 2007)

*FOR RUSTED NUTS & BOLTS*

CRC Industries Automotive


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## bighitter (Jun 4, 2008)

i actually have the same problem with my 93 HB. I am too wary to go below E. Humanure...you say a light comes on to warn you?? i believe we have the same truck. that would be nice if i did..always wondered if there was more fuel left..


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## Humanure (Feb 15, 2007)

Yes, I have a warning light that comes on when I am well below the E on the fuel gauge. Next time, I will take a pic showing the light on and how far I can go below the E.


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## bighitter (Jun 4, 2008)

Humanure said:


> Yes, I have a warning light that comes on when I am well below the E on the fuel gauge. Next time, I will take a pic showing the light on and how far I can go below the E.


Okay that would be cool. i dont really wish to see how far i can go below E. ahah i dont feel like pushing. a pic would be nice just to see how far it goes. Thanks!


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## Humanure (Feb 15, 2007)

Ok, finally got around to taking the pics. Both pics were taken while motor was running. The first pic below shows how far below the E I can take it. The tripmeter shows 314 miles; the low fuel warning light started to flicker on at mile 300. You can see the warning light below the red Brake light.









The second pic below shows where the needle rests after a complete fill up. It never gets near the Full mark. I think this is the reason why my needle can go so low.


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## Spinlock (Jun 12, 2006)

I just wanted to verify that the truck not registering full issue is not that uncommon: In other words, it happens on my 93. I have noticed that I can get closer to full if I pump my gas on the slowest setting (more of the fuel stays liquid, so the tank gets fuller of usable fuel.) Just for posterity, in case someone else sees this problem and panics. The low fuel light does indeed come on when I'm down to about 13 gallons, which is nice in a 15 gallon tank. I try to fill it before it dips below the "E" in any case.


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## pedxing (Jan 2, 2008)

This presents and interesting question though. The 'Low Fuel' light is obviously accurate and the gauge is not. So are they reading from different things? I always thought the Sending Unit and its floater controlled everything? Is there a separate switch/sensor for the 'Low Fuel' light?

Dustin


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## lumbee (Mar 20, 2005)

...sitting at a stop light this mor'n on the way to work, and I look down and notice my fuel gauge is dropping. I'm thinking OK, am I loosing fuel somewhere? Truck is running fine. After about 30 sec the gauge drops all the way down, way past E. After the light changes and I begin driving, the needle jumps back up to near full (just filled up yesterday). The rest of the drive through stop/go traffic it jumps around between 3/4 and full. Guess I'll keep an eye on it, and see if it gets any worse. My problem is my odometer doesn't work, so I don't have a backup if it goes out.

Oh, and on the fuel light thing, yes my truck has one, but I'v only seen it once or twice. I don't mind driving close to E, but I've noticed the truck can sputter when the fuel gets low...even before the fuel light comes on, so I fill up before I see it.


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