ArdWrknTrk Posted August 23, 2022 Share Posted August 23, 2022 Funny enough with a full tank and the engine running it is getting all the way to the full line. I guess the Dennis carpenter regulators aren't particularly precise either . I'd think they'd use an LDO or a buck converter... heck, even a zener diode and some transistors would be better than this??? (No, I'm not going to open mine up and see what they put in there... I'll design a custom piece if I get that mad at it...) --- Haven't run a full tank cycle yet, but between a topoff and a fillup so far it's working a *lot* better than before. Drops to just above 3/4 somewhat quick, but seems to drop at a more reasonable rate from there. If you're getting the pulsing around 5.5V it is just like stock, no matter what DC says. The SWAD-J that Gary is using is cheap and dead stable. All you need is a 9V battery clip, no need to reinvent the wheel. Link to comment Share on other sites More sharing options...
ratdude747 Posted August 23, 2022 Author Share Posted August 23, 2022 If you're getting the pulsing around 5.5V it is just like stock, no matter what DC says. The SWAD-J that Gary is using is cheap and dead stable. All you need is a 9V battery clip, no need to reinvent the wheel. It's a steady 5VDC (or whatever it was; matched up to what Gary set his adjustable unit to). No pulsing like the stock electromechanical units. I think the lack of pulsing is why the needles are slow to move... the pulsing helps break stiction in the gauge movement? My comment on rolling my own would be to design a custom circuit board (PCB) that would be a drop-in replacement without any hacking. I've designed several custom PCBs in the past and these days they're wicked cheap (and low enough lead time) from China. A hobby of mine if you will. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 23, 2022 Share Posted August 23, 2022 It's a steady 5VDC (or whatever it was; matched up to what Gary set his adjustable unit to). No pulsing like the stock electromechanical units. I think the lack of pulsing is why the needles are slow to move... the pulsing helps break stiction in the gauge movement? My comment on rolling my own would be to design a custom circuit board (PCB) that would be a drop-in replacement without any hacking. I've designed several custom PCBs in the past and these days they're wicked cheap (and low enough lead time) from China. A hobby of mine if you will. The gauges are like a reverse thermostat. The pulse isn't unsticking anything. They are damped by design and there is a reason. The fact these 6V gauges are from the 40's says all you need to know. Hey, if you like puttering with circuit boards PCBWay, JLC pcb and many others are a great resource. No more screwing around with acetate and nasty chemicals. Just make a Gerber file , or Eagle, whatever... and click a button. Link to comment Share on other sites More sharing options...
ratdude747 Posted August 23, 2022 Author Share Posted August 23, 2022 The gauges are like a reverse thermostat. The pulse isn't unsticking anything. They are damped by design and there is a reason. The fact these 6V gauges are from the 40's says all you need to know. Hey, if you like puttering with circuit boards PCBWay, JLC pcb and many others are a great resource. No more screwing around with acetate and nasty chemicals. Just make a Gerber file , or Eagle, whatever... and click a button. The last time I designed and ordered boards it was from AllPCB. Give them Gerbers and they do the rest. (I use KiCAD for designing such... been using it since my days in EET school). Anybody who visited my table at the truck show last year saw a bunch of my extra boards from the last several years on display. ---- That said, unless it becomes particularly bothersome, I'll probably keep the Dennis Carpenter unit. It works well *enough*, and is solid state at least. It's also possible that crimping down the contacts on the connector to the sending unit had an effect and this is how it shows. I didn't retest it after crimping (I noticed the connector felt a bit loose when I doing final assembly and happened to have needle nose pliers under the truck already). Link to comment Share on other sites More sharing options...
ratdude747 Posted August 30, 2022 Author Share Posted August 30, 2022 The last time I designed and ordered boards it was from AllPCB. Give them Gerbers and they do the rest. (I use KiCAD for designing such... been using it since my days in EET school). Anybody who visited my table at the truck show last year saw a bunch of my extra boards from the last several years on display. ---- That said, unless it becomes particularly bothersome, I'll probably keep the Dennis Carpenter unit. It works well *enough*, and is solid state at least. It's also possible that crimping down the contacts on the connector to the sending unit had an effect and this is how it shows. I didn't retest it after crimping (I noticed the connector felt a bit loose when I doing final assembly and happened to have needle nose pliers under the truck already). Had a full to empty to full cycle... took 14 gallons on a 19 gallon tank (needle almost touching the E mark, what was determined to be the lowest the gauge can read). Other than the occasional quick drop to 7/8, it's very linear... I'm calling it a win. Up next: the ultimate test... Gary's Truck Show! Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 30, 2022 Share Posted August 30, 2022 Had a full to empty to full cycle... took 14 gallons on a 19 gallon tank (needle almost touching the E mark, what was determined to be the lowest the gauge can read). Other than the occasional quick drop to 7/8, it's very linear... I'm calling it a win. Up next: the ultimate test... Gary's Truck Show! Bring it on, and safe travels! Link to comment Share on other sites More sharing options...
ratdude747 Posted June 2, 2023 Author Share Posted June 2, 2023 Had a full to empty to full cycle... took 14 gallons on a 19 gallon tank (needle almost touching the E mark, what was determined to be the lowest the gauge can read). Other than the occasional quick drop to 7/8, it's very linear... I'm calling it a win. Up next: the ultimate test... Gary's Truck Show! 10 month update: Full no longer reads as full but as 3/4 tank. Been like that since the winter. But it would seem to unstick and read full not long after filling up and driving While filling it up yesterday (on a long all-day drive home), I noticed something peculiar... the needle did read full during filling, but then dropped down to 3/4 by the time the pump clicked off. Yes I do leave accessory power on when filling. Due to not having an electric pump, I don't see it as enough of a hazard to have the sending unit power active during filling (and with as slow as the gauges are to warm up after power cycling, I don't like leaving it off if I want to ensure I actually got a good fill). Seems the upper end of the sending unit has marginally high resistance. Not bad enough to warrant dropping the tank or lifting the bed, but I will note it as a quirk. Knock on wood, but the rest of the range is OK still. Link to comment Share on other sites More sharing options...
Gary Lewis Posted June 2, 2023 Share Posted June 2, 2023 10 month update: Full no longer reads as full but as 3/4 tank. Been like that since the winter. But it would seem to unstick and read full not long after filling up and driving While filling it up yesterday (on a long all-day drive home), I noticed something peculiar... the needle did read full during filling, but then dropped down to 3/4 by the time the pump clicked off. Yes I do leave accessory power on when filling. Due to not having an electric pump, I don't see it as enough of a hazard to have the sending unit power active during filling (and with as slow as the gauges are to warm up after power cycling, I don't like leaving it off if I want to ensure I actually got a good fill). Seems the upper end of the sending unit has marginally high resistance. Not bad enough to warrant dropping the tank or lifting the bed, but I will note it as a quirk. Knock on wood, but the rest of the range is OK still. I've seen that and assumed like you that the top of the range has a problem. But, again like you, it wasn't bad enough to cause me to drop the tank. What I'm really interested in is the bottom end of the range, and if that works then I can use the trip odometer to see that it has only been a few miles since filling up and the gauge really should be reading full. Link to comment Share on other sites More sharing options...
1986F150Six Posted July 12, 2023 Share Posted July 12, 2023 Funny enough with a full tank and the engine running it is getting all the way to the full line. I guess the Dennis carpenter regulators aren't particularly precise either . I'd think they'd use an LDO or a buck converter... heck, even a zener diode and some transistors would be better than this??? (No, I'm not going to open mine up and see what they put in there... I'll design a custom piece if I get that mad at it...) --- Haven't run a full tank cycle yet, but between a topoff and a fillup so far it's working a *lot* better than before. Drops to just above 3/4 somewhat quick, but seems to drop at a more reasonable rate from there. https://www.ebay.com/itm/Gas-Tank-Sending-Unit-19-gallon-fuel-tank-1980-84-F100-350-Ford-Truck-NOS-/225642164958?_trksid=p2349526.m4383.l4275.c1#viTabs_0 Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 12, 2023 Share Posted July 12, 2023 https://www.ebay.com/itm/Gas-Tank-Sending-Unit-19-gallon-fuel-tank-1980-84-F100-350-Ford-Truck-NOS-/225642164958?_trksid=p2349526.m4383.l4275.c1#viTabs_0 Good find, David! That's a nice price and fits 1980 to 84: F100/350 - - 133" W/B F150/350(Super Cab) - - 155”,168" W/B F350(81) — (Regular Cab) 136.8", 160.8" W/B Link to comment Share on other sites More sharing options...
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