rb1949 Posted March 14, 2016 Report Posted March 14, 2016 More questions for your experienced wisdom please. Via the picture, I see 3 easy screws holding the instrument cluster in place. Does this allow it to slide forward enough to get behind it? There are 2 possible reasons, and I'm not even sure if I'm looking/starting in the right place. 1) the fuel gauge isn't working. The gas tank and sending unit were replaced, presume it was done properly. Guessing, the sending unit is accessible by removing a plate in the trunk? Check to verify the connection between the unit and the gauge. One wire? What am I looking for at the gauge, power, connections? Another project with only 2 parts. Any pictures? 2) The speedometer is erratic (bouncing) at lower than actual speed. The odometer does turn over. Where to look first for something obvious, top or bottom? Gears? Does the inner cable just pull out? (if damaged, I found a replacement). Did identify a knob on the lower dash, turn to reset trip odometer, but doesn't do anything. Or more complicated, something wrong with the speedometer itself. Process of elimination to figure things out. All advice appreciated. Quote
dpollo Posted March 14, 2016 Report Posted March 14, 2016 The removal of the three screws you have highlighted will allow the cluster to tip toward the steering wheel so you can, with some difficulty, change bulbs and so on but it will only tip forward if the speedo cable is either unfastened from the back of the speedometer or removed from the transmission and pushed back through the firewall enough to allow the gauge cluster to be moved. The inner speedo cable is removed from the top end and is to be lubricated VERY sparingly. It sounds to me like the speedometer drive pinion in the transmission has lost some teeth. It is easily removed, may be nylon toothed which is why I think it may have lost some and will have (had) 16, 17, or 18 teeth depending on the rear axle ratio. They interchange with all Dodge Plymouth Chrysler and Desoto of that era. The fuel sender in the tank is likely the culprit on your non working gauge Remove the cover and wire and ground the wire at the tank through a test light or small 6 v bulb. The dash gauge should then register about 1/3. Maybe your new tank is poorly grounded because of too much paint. In any case, the sender is easily removed by twisting the collar which holds it down. There is a special tool for doing this but it can be done with a small brass drift. Do not use a steel screwdriver to loosen the collar because you do not want to cause any sparks here as the tank is opened. As you have correctly assumed, the gauge circuit is grounded through a single wire to the tank unit. 2 Quote
busycoupe Posted March 14, 2016 Report Posted March 14, 2016 On my 48 Dodge the speedometer has a small oiling hole on the back, just above where the cable screws in. A couple of drops of light oil into this hole in the speedo head stopped my speedometer from jumping. I used a "zoomspout" oiler to get in there from behind without removing the cluster. I'm not sure if the 49 Chrysler is similar, but it may be worth checking. 1 Quote
Dodgeb4ya Posted March 14, 2016 Report Posted March 14, 2016 (edited) This is probably all you will get as for easily seeing the back of the cluster.. Unless you remove the firewall retainer/rubber insulator for the oil line hose ,speedometer cable ,temp gauge sender. Even then it's tight. Cover the steering column tube so as to not scratch the paint. Edited March 14, 2016 by Dodgeb4ya Quote
Dodgeb4ya Posted March 14, 2016 Report Posted March 14, 2016 This is probably all you will get as for easily seeing the back of the cluster.. Unless you remove the firewall retainer/rubber insulator for the oil line hose ,speedometer cable ,temp gauge sender. Even then it's tight. Quote
rb1949 Posted March 17, 2016 Author Report Posted March 17, 2016 Thanks, getting behind with interior light repairs. Finally removed that cover plate in the trunk to expose the sending unit. As advised, jumped it to ground, but no movement in the fuel gauge. (key on). Probably next, track that wire up to the gauge for the connection, so cluster will have to come loose to find it. 2 wires on the gauge, power and unit? If all wires are good, does that indicate a bad gauge? Cold spell returning which will limit activity. Will advise/ask as things progress. Quote
rb1949 Posted March 27, 2016 Author Report Posted March 27, 2016 The single wire from the top of the unit to the back of the gauge tests OK. But did not see 6V on the other gauge terminal. Jumped a wire from the battery to that terminal, still nothing. Easy access in the trunk, pulled the unit. Unit to gauge - battery to gauge. Moved float, and nothing. Starting to look like a defective gauge, and may have to pop for one. With the unit out, should I test for resistance with the float up and down? New question: There are 5 wires that run to the rear lights. Are these under the car, by the driver rocker panel? They come up into the trunk, from somewhere. Quote
Dodgeb4ya Posted March 28, 2016 Report Posted March 28, 2016 (edited) The tank float unit is almost always the reason the 1949 and up fuel gauge does not work if the car still is stock and the wiring has not been tampered with.. Some times The tank unit resistor cone winding un-ravels or the cone breaks off and is laying inside of the cone enclosure cover. You can carefully bend the tab and lift off the little enclosure exposing the cone and wiper arm. You can use a ohm meter to check the tank float assembly. Your car is the one year only model 1949 chrysler so I might be wrong but i think the tail lights, turn signals and fuel gauge and brake come from the roof down into the trunk . Not sure about back up lamps whether from above or along the frame. Edited March 28, 2016 by Dodgeb4ya 1 Quote
rb1949 Posted March 28, 2016 Author Report Posted March 28, 2016 Remember, the unit is new, but not tested by me. Will pop it back out. For Chrysler, the number should read about 10Ω empty and 90Ω full. (?) Not getting any Ω reading across the 2 gauge terminals. Did not remove gauge yet to look for anything obnoxious. Jumping power from the Batt. Have not been able to track wire to gauge to identify lack of 6v, which should come from ign switch. DID find troubleshooting fuel in the manual. Describes AC & Ford/King-Seely single wire setups. Start over. That 'clump' of wires coming into the trunk seems to be heading downwards. Have not been underneath yet. Anyhow, I think they should be replaced. Will have to measure and contemplate making a 5 wire harness. Running it along the frame would not be a problem. Hooking it all up is a different story. Most of it seems to be 16GA wire. 1 Quote
dpollo Posted March 29, 2016 Report Posted March 29, 2016 The wires to the back usually run up the left front windshield post and above the door(s) before coming down into the trunk. to re route along the frame would be easy if you use the flat wire made for trailer wiring. It could be laid under the carpet. It has 4 conductors laid flat and bonded together. green, yellow, brown, white, 14 gauge. (14/4) You will need 6 wires , one for tail lights, left turn signal, right turn signal, live wire to stop light switch. return to turn signal switch and finally, the fuel gauge. If your car has back up lights , add another for a total of seven. You could use the eighth conductor to power a trunk light which many Chryslers of this era had. It took power from the stop light switch feed. 1 Quote
Niel Hoback Posted March 29, 2016 Report Posted March 29, 2016 Trailer wiring is a little light for 6 volt use. You might want to use something heavier. 1 Quote
rb1949 Posted March 29, 2016 Author Report Posted March 29, 2016 (edited) dpollo did mention that 4 conductor wire was 14GA. I'm looking at 16GA. Original was ?? edit: looked again, there are 8 wires going back, not 5. Quite a clump. Edited March 30, 2016 by rb1949 Quote
Young Ed Posted March 30, 2016 Report Posted March 30, 2016 original wiring for most of the lights was 16ga. I'd upgrade to the 14 if you can. Quote
rb1949 Posted March 31, 2016 Author Report Posted March 31, 2016 Will probably stick with 16, served well for quite a few years, except for the insulation. Estimates on the amount of wire are adding up! And, happened to be reading some "resto judging" rules. Using today's modern wire knocks you out of the park for originality. You need that cloth covered wire. Do I care? (Not). So do I assume that people who wish to invest in a replacement harness are going to get the original style cloth covered wire? Or are there choices depending on what their intention is? Quote
rb1949 Posted April 4, 2016 Author Report Posted April 4, 2016 Fiddling around the left dash, found another Map Light. Ha. Of course, no bulb. Now it works, and have two. Finally pulled out the fuel gauge. Yikes, what delicate thread-like wires on that thing. Don't drop it. Odd balance, when you hold it upside down, the needle goes to F. Gave it a dab of oil. So needle moves. Tests OK across terminals. Sending unit was back out. It tests within Chrysler specs for resistance. Let's jump this thing together with gauge out. Power to gauge. Gauge to ground. Unit to gauge. Unit to ground. Operate float, and the dang thing is working!! Up & down, E to F. WOOHOO! Just in time for a couple cold weather day delays, and a hailstorm. Better today, so put gauge back in the cluster. Sending unit back in tank. Soldered a wire to the locking retainer ring to run to ground. Jumped new wire from unit to gauge. Power to gauge. Needle registered about 1/3, which is about how much gas was in the tank. Thank goodness for results. Attached new wire to unit and under the carpet to the side. Have obtained all supplies to begin constructing a new 8 wire harness from front to back. Can install it, somewhere. New wires to lamp sockets in the trunk shouldn't be too bad. Trying to figure out the front is a different story. I cannot see, nor get to anything behind the dash. Dastardly words and work are probably on tap.If you have a secret, please advise. 1 Quote
dpollo Posted April 5, 2016 Report Posted April 5, 2016 I went to Quebec and studied French. Now I can curse in two languages. There is no easy way to deal with that dashboard other than , perhaps, removing the front seat so you can get under or if the windshield is out, reaching in that way. Chances are, the wiring under there is OK and the less you disturb it the better. Quote
rb1949 Posted April 5, 2016 Author Report Posted April 5, 2016 The cluster is going to have to be removed and get it out of the way. Looks like the temp & oil can be removed at the gauge(?) If not, they need to be disconnected under the hood and pulled thru the firewall grommet. If successful, then the housing that the cluster mounts into should come off, providing yet a bigger opening to work. Test question: with speedometer in hand, what's a good way to spin it and see if it works OK? A drill? 1 Quote
Don Coatney Posted April 5, 2016 Report Posted April 5, 2016 Oil line can be unscrewed from the dash. Temperature gauge must be removed from the head. Drill motor works well. Quote
rb1949 Posted April 5, 2016 Author Report Posted April 5, 2016 Thanks for the tips. Just don't start with oil line removed. (Unless it can be capped?) Whoops, speedo test would need extra speedo cable. Foiled again. Was out there for an hour and got cold. Like your table top cover .... Mopar thinking juice. Quote
dpollo Posted April 5, 2016 Report Posted April 5, 2016 (edited) Be really careful when removing the temp bulb from the head. DO NOT FORCE IT ! If necessary remove the soft plug above the bulb and ease it out with a soft tool. I do not mean to scare you but repairing a temp gauge of this type is a very expensive proposition. Also note that the line connection to the oil gauge is not a regular flare fitting, but has a ball shaped brass seal which at one time was available through the parts service. Not any more. It can be re used but be careful with it. Edited April 6, 2016 by dpollo Quote
Young Ed Posted April 6, 2016 Report Posted April 6, 2016 a #2 square drive should turn the speedo Quote
Dodgeb4ya Posted April 6, 2016 Report Posted April 6, 2016 (edited) Here are pics of the 1949-50 Chrysler oil line ferrule and the back side of an easy service dash cluster... Edited April 6, 2016 by Dodgeb4ya Quote
rb1949 Posted April 6, 2016 Author Report Posted April 6, 2016 Advice with pictures appreciated. But weather delays again, wet & cool. The garage is a bit small, and dark. Although this is an interior project. Could screw a 4' shop light up inside the car. Will be picking up new pigtails for the rear lamps (that springy contact thing inside the socket). This topic will stay active as necessary, and will probably start another for other issues. Searching old topics also pops up some good information. If you're new, use it. Thanks to all who have jumped in to help. Quote
Don Coatney Posted April 6, 2016 Report Posted April 6, 2016 I once installed new two pole sockets in my P15 tail lights by soldering them in place. Your car may be different. Quote
Young Ed Posted April 6, 2016 Report Posted April 6, 2016 I put dual filament pigtails in my orignal sockets. The only tricky part there is you don't get the offset pins so during bulb replacement you have to make sure you put them in correctly. Quote
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