My 71 Duster work in progress

[b-body-bob]

No need to change the terminal. Try mildly deforming it with a pair of pliers. It doesn't have to touch all the way around, it just has to touch consistently.

The terminal is smaller than the stud. I wish it was the opposite. I guess for insulation I'll need to spray it with some of that stuff from TV they use to make a boat out of a screen door. /s

The fucker still doesn't work though. I jumpered the terminal to the stud and still nothing. I grounded it with a jumper, and I confirmed it's continuous with the rear bumper. It must be empty but It's got some gas in it so it seems like the needle should move. I took about 2 gals out after I removed the sender, so I may add a gallon to see if that moves the needle any. A gallon keeps me below the take a bath level in case the sender has to come back out.

 

[69.5CUDA]

if the fuel level in the tank is anywhere neer the level of the sender hole you should at the very least see 1/4 tank or more

did i miss where you managed to get 1/2 and full thru the sender outside the tank?

 

[b-body-bob]

if the fuel level in the tank is anywhere neer the level of the sender hole you should at the very least see 1/4 tank or more

did i miss where you managed to get 1/2 and full thru the sender outside the tank?

The fuel level seems to be about an inch below the sender hole.

I might not have written it down but I did check the sender outside the tank before I put it back in, and it worked. I think that was the point where I realized that the primary problem was due to the terminal not fitting the stud.

It seems like it must be a problem with the ground, but I'm not seeing that in reality. I was tempted to run a separate ground from it all the way back to the battery but stopped short of that once I saw it was continuous with the bumper. Also, FWIW, the tank itself didn't seem to be grounded but that might be due to the coating on the outside of it.

 

[Dr.Jass]

The factory connector should look like the one for the temp sender, i.e. a little right-angle spark-plug boot lookin' job. When I pushed mine on, I could feel the sender threads grating along the metal as it seated. Is the terminal inside the boot deformed, where you're pushing the terminal on to what feels like seated but the stud isn't contacting the terminal?

 

[Dr.Jass]

The only other suggestion I have at this point is to put one probe of your DMM in the connector near the door, and the other end in the terminal (tank) end of the wire. Wobble the terminal around, then flex the wire along its length between the terminal end and the body. There could be an internal break somewhere along that wire, if not right at the terminal boot itself.

 

[b-body-bob]

The factory connector should look like the one for the temp sender, i.e. a little right-angle spark-plug boot lookin' job. When I pushed mine on, I could feel the sender threads grating along the metal as it seated. Is the terminal inside the boot deformed, where you're pushing the terminal on to what feels like seated but the stud isn't contacting the terminal?

That's the same connector I had. There's no grating or anything like that, and you could tell that it wasn't seated at all with it shoved on as far as it would go.

At first I thought the rubber sleeve on it was too tight to go on to connector on the sender sender far enough, so at this point it's trimmed all the way back flat to the part where the metal is. It still won't even start on the stud. I gave up and switched back to using the jumper and will fix the terminal later.

The only other suggestion I have at this point is to put one probe of your DMM in the connector near the door, and the other end in the terminal (tank) end of the wire. Wobble the terminal around, then flex the wire along its length between the terminal end and the body. There could be an internal break somewhere along that wire, if not right at the terminal boot itself.

Yeah but it reliably passes the ground the wire test so I'm thinking there's no way it's that wire. I'm going to focus on the ground some more, maybe this time just ground it from the suction nipple on the sender all the way up to the battery to be sure. But, continuity between the sender and the back bumper should mean it's grounded.

It beats the hell out of me as to what could be wrong.

 

[b-body-bob]

I haven't gone into full dirty mechanic mode yet today but I did verify that the bumper and the negative battery cable have continuity. FWIW I used an extension cord, with an alligator jumper on the male end at the battery and a screwdriver shoved in the ground socket on the other end with the DMM testing between the screwdriver and the bumper. Beep.
.
So, wiring is good, the sender is grounded to the bumper that is grounded to the battery so the sender is fully grounded. Also, grounding the sender wire to the connection of the ground wire at the vent on the sender causes the gauge to go to F. So again, the grounding is A-OK. The voltage limiter is working as evidenced by the video earlier. What the hell could be wrong?

I'm going to take the sender back out to convince myself again that it works out of the tank. Mostly because I don't know what else to do, and I'm waiting on speedo parts to work on anything else. But I know it worked laying under the car.

 

[b-body-bob]

OK, the sender does work laying under the car. As predicted It doesn't quite get to full and it might be reading empty before it should. Both of those conditions are fine with me and leave no excuse for running out of gas.

The pickup was wet but after turning it around to get it out of there it's hard to say how wet. Maybe it is just empty. I did the finger test again and it's more like 2" below the edge of the sender hole.

I have a new gasket coming tomorrow and I'm going to put it back together, add gas, and see if it registers or not. I'm basically done with it for now, whether it works or not.

 

[Dr.Jass]

The point I was trying to make about checking the wire whilst wiggling/manoeuvering it around was that you could have continuity in one position and not in another... i.e. when it's "stretched out" to reach the sender, the conductors in the wire lose contact. I say this because Stretchy-Poo has been having a very similar issue with the TIPM in his truck. A wire soldered into a ring terminal was intermittently losing connection, causing all kinds of crazy shit with the complex electrical system in the truck. I really think your wiring's OK, but we thought Stretch's truck was too. It worked well for a week and then another loose terminal reared its head today, with the exact-same symptoms.

One further thing: Did you check the sender all along its travel? It's entirely possible something's deformed inside the rheostat causing the wiper to lose contact in the middle of its travel, whilst touching at the ends. The resistor is banana-shaped inside that case... maybe the banana wasn't installed straight or got dislodged/jarred in shipping and now most of its shape curves away from the wiper. Were that the case, the sender would register correctly at either end of the scale (E and F), yet register exactly squat nearly anywhere else in its travel. You won't have the gasket until tomorrow anyhow; it's worth checking in the meantime. As I recall, it's just three bent-over tabs to remove the rheostat cover--you know, the kind where you stab yourself whilst trying to pry them open. Get stabby and have a peek in there. The worst thing that can happen is you'll still have a not-functioning gauge sender. It's not like you'll void the warranty.

 

[71dusterman]

As Jass implied, if the elbow plug doesn't have a good grating feel when you slide it on the sensor plug, that is where I think you are loosing the connection. I would try to get a new one and splice it into the wire so you get a good solid connection no matter how much you twist and turn it. Without the grating you don't have a good connection and it will be flaky.

 

[b-body-bob]

Guys, I can't even slide the plug on to the sensor., it's too small to fit over the stud. That is definitely why it wasn't working - I didn't realize it wasn't making contact at all but it's not. Since I noticed that, I have connected the wiring to the sender using a jumper with alligator clips. With the jumper, there is no doubt that it is making contact. But the gauge still doesn't respond.

Yes while I had it out I checked it all along the travel, well, at a lot of places along the travel. The gauge responded to all that as expected. Using a jumper on the sender wire:

1. The wiring is good. The ground is solid and when I connect the ground to the sender wire, the gauge goes to full.
2. The voltage limiter is working. See video above.
3. The sender affects the gauge position when it is out of the tank and I move the float by hand.
4. With the sender back in the tank connected to the wiring with a jumper, not the original wire, the gauge stays pegged to E. The wiring and voltage limiter tests still pass.
5. I checked ground at the face of the sender to the rear bumper, and it is certainly grounded.
6. When I take it back out of the tank, it works again- see 3 above.

That leaves me with one unknown: is the fuel level low enough to actually read Empty at the gauge?

That is the simplest answer after all that testing and actually it seems to be the only answer. We will see when I dump the 5 gallons I siphoned out back in it. I won't be surprised if that's not the problem, but I'm done with fooling around with it for now. Retesting things gets me nowhere. I gotta move on.

 

[b-body-bob]

I learned one thing yesterday, a speedo cable that says "fits most" will be at least a foot too long for an A-body. It also didn't come with a grommet and after 50 years the original one was rotten. At least the cable was inexpensive. The shorter cables are 2x as much. So I've got that going for me, I guess.

I still haven't put gas back in it yet, but the sending unit is reinstalled and the distributor has one of the Mr. Gasket springs in it and the right vac canister. IIRC the canister had 16 stamped in the arm.

Today is "I hope the neighbors don't have an open house scheduled" day since I've got to fire it up and set the timing, adjust the carb, etc. It's a pricy house. I can't imagine anyone would spend anywhere near their price and end up living across the street from my garage. SURPRISE!

But seriously, I'm actually pretty quiet compared to others I know.

 

[Dr.Jass]

I learned one thing yesterday, a speedo cable that says "fits most" will be at least a foot too long for an A-body. It also didn't come with a grommet and after 50 years the original one was rotten. At least the cable was inexpensive. The shorter cables are 2x as much. So I've got that going for me, I guess.

This is an ongoing issue with cables, and I'm not quite sure who to blame. I'm assuming you got an ATP or Pioneer, both of whom list 80" as the right cable length. I believe we ended up using the ATP Y829 on his car, which is 60" long, but can't confirm that at the moment. The factory parts book only shows one cable for most applications: 2889783. No length is given, however the cable core package (no sheath) is listed @ 80". I believe that needed to be cut to fit, but can't confirm it as I don't have an instruction sheet and nothing's listed in the service manual (that I could find). On the Valiant, I believe I just used a reproduction.

I still haven't put gas back in it yet, but the sending unit is reinstalled and the distributor has one of the Mr. Gasket springs in it and the right vac canister. IIRC the canister had 16 stamped in the arm.

That's a good one. While I was clearing space in the garage to get the Challenger out, I found one lying on the floor stamped "11". I think that's the same as what's in the W2 engine, but can't remember. With 35-36° total, that should put you near the low-50s at part-throttle cruise, such as highway speed. That's a good place to be. If you get spark knock at lower speed you should be able to adjust the spring tension to slow the rate a little, so that your "25MPH" vacuum isn't enough to fully overcome the tension but your 70MPH is... just one more thing to tune if you're not happy with the immediate result.

Today is "I hope the neighbors don't have an open house scheduled" day since I've got to fire it up and set the timing, adjust the carb, etc. It's a pricy house. I can't imagine anyone would spend anywhere near their price and end up living across the street from my garage. SURPRISE!

But seriously, I'm actually pretty quiet compared to others I know.

A lot of neighbors have come and gone over the years here, but this end of the block has remained pretty consistent. New or old, my neighbors have been very tolerant of, and even spectators to, the nonsense in the garage and back yard. I've always been pretty respectful of time, though, and it's not something I'm doing constantly anyhow. There's no open-header silliness or attempts at tuning after about 8:30PM nor before 9AM. If they have something to say--and nobody has in 19 years--I'll go over and ask them to tone it down the next time their lawnmower or weedeater is running. Tit for tat, so to speak.

 

[69.5CUDA]

as someone whose cut down a few speedo cables, lemmy part some advice, clean the shit out of it even if its new, soilder the section you want to cut before you cut it, stuff it in to place and then push..HARD and see how much it "springs" before you cut, then run it down with a file, ive actualy made half mile long speedo cables from vans n trucks fit cars and other oddballs, getting the "square" re-cut in is kinda an art on a round cable but with it souldered you can do it and it wont try to come apart...hell ive replace motorcycle cables with car units, a siingle car unit will net 3-4 bike cables

 

[b-body-bob]

This is an ongoing issue with cables, and I'm not quite sure who to blame. I'm assuming you got an ATP or Pioneer, both of whom list 80" as the right cable length. I believe we ended up using the ATP Y829 on his car, which is 60" long, but can't confirm that at the moment. The factory parts book only shows one cable for most applications: 2889783. No length is given, however the cable core package (no sheath) is listed @ 80". I believe that needed to be cut to fit, but can't confirm it as I don't have an instruction sheet and nothing's listed in the service manual (that I could find). On the Valiant, I believe I just used a reproduction.

This came from Mancini and is 80" long. The one that came out stretched out on the floor as best I could (mark one end work toward the other end, mark that, measure between) was 63-1/2"

I looped it under the crossmember and then back around to the transmission, with a zip tie as insurance that it won't get on the exhaust. It's in all the factory clips too. It wasn't as bad as I thought once I saw that solution.

That's a good one. While I was clearing space in the garage to get the Challenger out, I found one lying on the floor stamped "11". I think that's the same as what's in the W2 engine, but can't remember. With 35-36° total, that should put you near the low-50s at part-throttle cruise, such as highway speed. That's a good place to be. If you get spark knock at lower speed you should be able to adjust the spring tension to slow the rate a little, so that your "25MPH" vacuum isn't enough to fully overcome the tension but your 70MPH is... just one more thing to tune if you're not happy with the immediate result.

I found that even though it's got the hex nipple on it, it's not adjustable according to Mancini's website so that rule of thumb might not always be true.

A lot of neighbors have come and gone over the years here, but this end of the block has remained pretty consistent. New or old, my neighbors have been very tolerant of, and even spectators to, the nonsense in the garage and back yard. I've always been pretty respectful of time, though, and it's not something I'm doing constantly anyhow. There's no open-header silliness or attempts at tuning after about 8:30PM nor before 9AM. If they have something to say--and nobody has in 19 years--I'll go over and ask them to tone it down the next time their lawnmower or weedeater is running. Tit for tat, so to speak.

Historically my cars are broken down more than they're making noise.

There is also the issue of the breaking bad van/camper outside my garage and right in their line of sight ...
On the gas gauge, it barely moves with 5 gals added. I took a video to convince myself I wasn't fooling myself. I let it go 1 minute on, then one minute off.

 

[b-body-bob]

I'm not surprised how I fix one thing and two others stop working

All weekend long I used the oil light as indication that I had the key turned to run. When I went to actually start the car, the oil light didn't work. I've got no idea why.

Also, you can see in the video above, my speedo is stuck at about 10 MPH. That has something to do with the cable, but what, I don't know. If the cable's not turning the thing should go to zero, right? At that point I had installed the cable but not started the car so it hadn't turned at that point.

 

[b-body-bob]

I just realized that video is after the cable was installed and before the car was started. That in turn reminded me that I had to twist the cable end around under the dash because I wanted the clip on the bottom. I had connected the trans end first, because why not I was under there already, right? So me turning the housing probably put a twist in the cable that is reflected on the gauge, so I gotta fix that. Hopefully just disconnecting it at the transmission will let the cable relax and it'll be back on zero.

 

[69.5CUDA]

no
the cable twists at X rpm to which it spins a rotating mass that basicly induces a gravitational pull to hold the speedo needle up....so unless youve got that cable spinning its not going to hold the needle up

what im guessing is that either A youve got some sticky parts in your speedo or B its loose enough that you managed to slightly clock some internals

 

[b-body-bob]

That's what I thought, how could it not be zero if the cable's not turning?

Other than turning the housing, all I did was shove the cable up on the back of the speedometer and make sure it clicked in.

It was on zero in photos prior to installing the cable. I spun it up to 30 yesterday. I just looked, and it's still stuck just below 10.

 

[Dr.Jass]

The factory lubricant in the needle-shaft bearings gets sticky with age. That's the most-likely problem; it happens to tachometers as well. As far as I know you don't really have access to the one nearest the face without removing the face itself. I would probably try something like Lock-Ease, aiming the straw in there as close as you can. Then work the needle back and forth via the drum (so you don't upset the needle's at-rest position and hence, accuracy). Rinse, repeat.

Yeah, you'll have little choice but to disassemble the cluster to do it. While you're in there, try the same trick for the fly-magnet bearings. A squeaking speedometer will drive you nuts.

Auto Instruments charges something like $250 to disassemble and re-lubricate the needle and fly-magnet shafts.