gas gauge

[kglowacky]

took my truck for its first ride. The gas gauge works perfectly standing still as I go down the road it is going up and down as the gasoline slashes around in the tank. i know my 78 didn' have baffles but is there a resistor or something that I need to wire in the new harness I have that stops this?

[Bandit130]

Check out this video.

https://www.youtube.com/watch?v=HuGfmgNPTS0

[kglowacky]

looks like I need a new gauge. Thanks

[Bandit130]

What year is your truck?

[78 Big10 454]

I had this exact same problem in my 78. A new gauge didn't work. I traced the wiring and found that the wire had worn insulation and was shorting out on the frame. This was under the cab below the passenger side door.

[Palf70Step]

I have noticed that swing on just about every early GM truck, even when they were new. All the ones I see don't seem to act up till you are around 1/4 to 3/8 tank. I have tried several things, but never seem to get rid of the swing.

[kglowacky]

1978 i will put more gas in it and see what happens


Just rewired my truck with a new painless harness so I think the wiring is not the issue

[Rich84]

That's just what these gauges do. Mine all seem to float around a bit. New senders, old senders, new wiring old wiring.

[Dleslie212]

Originally Posted by kglowacky

1978 i will put more gas in it and see what happens


Just rewired my truck with a new painless harness so I think the wiring is not the issue

How difficult and time consuming was the Painless kit to install? That is probably my next big project on my 77 K10, but I’m terrible with electrical stuff. I’m wondering how bad it’s going to suck for me to do. Which kit did you use? Were you happy with Painless?

[kglowacky]

I used kit # 10201 28 Circuits. I am not finished yet but pretty close. First let me say I am doing a LS1 swap so part of my new Painless harness I did not use. It is all the engine bay stuff. Next let me say any re wire takes time and patience . This was a universal harness so somethings just are not like factory but painless has a way to make it work. Painless has a very very good installation manual and it is also online so perfect to trouble shot. The big difference I see between Painless and OEM is Painless does not have a firewall disconnect plug so if you pull the front nose off your truck you will need to take all the wiring off the front and roll it up in the cab. Painless does a good job of keeping as many as possible the same color of oem wire with their wires. There are some plug and play harnesses out there you may want to use. They are around 800 but I think it would be a easier way to go if you are going original.

I am planning on posting a recap of this harness once it is completed and running down the road.

Not sure I would say it was difficult but I will say you need to go at a pace that keeps you from making mistakes.