I have a 69 dart convert and I have a question about the temp gauge. For some reason the car has a wire coming from water temp sending unit to a small red light under the dash that I assume illuminates when water temp get to hot but theres no way to see it unless u put your head under dash. I just removed the instrument cluster to see if maybe the reason was because the temp gauge was bad. I ran a ohm meter over all the contacts on circuit board and also did the 2 c battery test and the gauge moves about half way when doing the test. Also there are no wires on the studs coming out of the instrument cluster is that normal? My question is how in the heck can I fix the gauge to work like normal? I can get pics if it helps thanks for your time.
violet is from the temp sending unit.dark blue wire is from the fuel sending unitblack is switched 12V+ from the ignition switchlight green is left turn. orange is the instrument light variable power.on the other circuit boardred is the High beam indicatordark blue is switched powertan seems to be the same as light green.. ???Orange is the instrument cluster bulb variable power.grey is the oil pressure switchbig black on the threaded stud is from the alternator output. big red on the threaded stud is from the starter relay and battery positive.there should also be a ground wire connected.. probably to the TOP connector on the instrument cluster voltage regulator..
pictures would be nice.. i might be able to work with them to assist you.. so... lets deal with the violet wire... ohm your temp sending unit.. start at 200 Ohm scale.. see if there is any continuity.. i don't know what the range is right now.. so turn the range knob to see if its picked up on the other ranges.. if you get some resistance. plug the wire back into the sender..behind the dashboard.. find the violet wire again.. probably to the left side cluster pins. ohm that wire to ground.. does it have very close to the same resistance..if somebody could not get the gauges to work.. they might have changed the sending unit from a temp sending unit to a temp switch.. temp sending units are a variable resistance temp switches are OFF and turn ON/short to ground at overheat temps.. so they turn on the lamp when the engine overheats..
I have some pictures but I can't for the life of me figure out how to post them
photobucket.. its free.. paste a link from there.i might have created something to help a bunch..this is bigger than you can see.. click and open the image in a new window. or move the slider below..
heres the pics http://s1371.photobucket.com/user/cbroper73/library/Dart%20Instrument?sort=3&page=1
what i cannot see is how the cluster is PROPERLY GROUNDED>. could it be from the tab looking thing above and left of the speedo threaded connection.. you might want to remove the screw above the IVCR. and add a ring terminal on the end of a wire and the other end hooked to a good ground.. you might invest in a pair of .250 insulated quick connects for that wire mid point.. so you can connect it with the dash part way out but there is no way for the middle disconnects to touch anything else under the dash.. insulated quick connects are totally encased in plastic.. no exposed metal..Dorman/Conduct-Tite male/female fully insulated quick-disconnect terminal setPart Number: 85461 Type: Quick Disconnect Terminal Gauge: 16-14 Gaugejust a thought..wait... i found pictures just like the ones you posted.. oh.. wait. these are yours.. nice pics..
haha I try to take good pics! Ok as far as the ground I didn't disconnect a solo ground from the cluster. Second if the sending unit wire is not going to temp gauge it can't read the temp. The blue wire in pic is going from sending unit to red light and it stops there. Could I not remove that and attach to the violet wire do get the "data" going to the gauge?
yes... you might be able to move the wire to the PURPLE circuit.. please find the rest of the wire under the hood.. or in the harness to make sure its NOT grounded.. or to find if somebody just spliced in some blue wire..if the sending unit resistance is WRONG.. your gauge will NOT be accurate.. i looked up the specs for the original 69 dart sending units.. so in your bottom picture that shows the manifold and temp unit.. OHM that. does it have continuity?? at some range on the OHM meter?? or is it a SWITCH that's OPEN. the original sending unit for a 69 is a wells TU22 style.. resistance at 100F, 132.4 to 161.8 ohmsresistance at 220F, 19.9 to 22.1 ohms1/8-27 pipe threaduses a bullet connection.
yes it does the sending unit is brand new
OOOOHHHHMMMMMMMM s.. that looks like a switch type from here.. OPEN.. instead of a variable resistance.. looks like you can set the meter to 200 OHM scale and test..SAY... in the picture of the MANIFOLD.. whats that sender on the left with the RIGHT angle boot.. thats the temp sender for the gauge.. what color wires is on that...?? violet???OHM that one..check the resistance /continuity of that wire unplugged from the sensor to the violet wire to the cluster connector..oh... and also.. do you have a good braided ground connection from the engine block.. usually at the back of the head or intake to the firewall.. so the ground circuit is correct??? and what does the cluster ground too?????? no ground to the cluster.. you wont have much gauge operation.. does the fuel gauge work???? is is accurate????
Ill have to figure out how to set my multi meter to a scale idk if it does that its a digital blue point meter. But i will test the ohm and bring back the readings.
edited above.. check the rubber booted sensor next to the one with the blue wire.. thats the coolant temp sensor.. read edit above..
ok checked the other sensor and was reading between 290-300 ohms checked continuity of wire to instrument cluster and there was continuity so theres no break in the line. wierd thing is the wire color is brown at sensor but violet at cluster
also im assuming the cluster isn't grounded at all unless it ground via alternator current ground there no ground to anything else on the cluster. There is a braided ground from engine to fire wall and its pristine this car has had a frame off restore done.