Cluster Woes

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BillyBob0780

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Hi Folks I hope everyone is well as they can be ?
Could I ask for some assistance? I have recently bought a 73 Dodge Dart 318... apparently it was in Dark Shadows... Anyway it had a few owners and I'm working through all the faults. I had to buy a used cluster and due to the pain of taking the cluster out I thought I'd replace all the bulbs as most were busted and the headlight switch was busted. I found that even after changing the bulbs and testing the printed circuit the oil pressure light and the direction indicators don't work. I've replaced the oil switch as there is power going to it. Any thoughts ? Common issues ?
 
Oil pressure light only turns on when the pressure switch closes (completes circuit to earth)

Turn signals.
Turn signals get power through the flasher unit. The flasher only gets power when the key is in RUN and/or accessory position.
There is also a second path to the same lamps, this is through the hazzard switch. Exactly how this is done varied from year to year but in all cases the hazzard flasher is always connected to power (works with key off). I beleive in most years it has a fuse.
 
Schematic for your '73 looks something close to this
upload_2021-8-2_11-32-52.png


With key off, turn on the hazzards. Ammeter should should repreated slight discharge from the battery.
All four corners outside the car should be blinking. Both indicators on the instrument panel should be blinking.
A few years the indicators were on the fenders - doubt that's your case.

Then compare to when engine is running and the turn signals are switched on.
Also compare with parking lights on. Many years/models the same lamp is used for several functions (two filaments).
 
A couple of things to check for the oil pressure light:
First is to make sure you're using the correct sender-
Sender for warning light:
PS11T_Front__ra_t.jpg
or
PS-11_Front__ra_t.jpg


Sender for gauge:
PS59T_Front__ra_t.jpg

They are not interchangeable- the gauge sender will not work properly with a light, and vice-versa.

Second is to be sure you did not use any sealer or teflon tape on the threads when you install the sender. This can prevent the sender from grounding properly and not functioning. Check with an ohmmeter from the body of the sender (NOT the connector) to a known good ground on the engine. Reading should be at or near 0 ohms.
 
While answers above are technically correct as far as they go................thread these problems in an "end to end" manner. THINK about where it starts, where it goes, where it ends, and what happens in between

For example, oil lamp

MUST have correct sender. Gauge type and warning lamp senders are different...........there is a connector on the sender wire somewhat subject to poor connection (general statement, any terminal can fail)

Bulkhead feed through terminal. This can corrode, fail, poor connection

Harness connector at the cluster pc board THESE ARE A BIGGIE. These pins on the pc bard are "riveted" and can work loose / corrode. Solder them to the pc board traces

Lamp sockets.........these have spring fingers which make contact with the PC board traces. Clean the traces with an abrasive eraser. If you don't have, maybe something like REALLY fine sandpaper. Clean and bend the socket contacts for better contact, clean the inside where the bulb fits or replace socket. Check the lamp, make certain it works or replace. Is the lamp shell and contact clean?

Power goes through the lamp and back to a common point on the cluster where it gets power from the ignition switch so THAT must be working, and that is yet another possiblity of a bad pin on the PC board

GENERAL PROBLEMS with cluster and I would check all of them while it's out of the dash

1...As mentioned, pc board pins, solder them
2...The IVR/ regulator for the gauges plugs in on a non-Ralley dash, and the contact fingers can lose contact with the board traces. Solder jumper across from the contact fingers to the traces
3....Gauge studs have "fake" nuts. Consider replacing, and loosen/ tighten these nuts several times to 'scrub' the board clean and make good contact
4....Consider checking the gauges for accuracy. You can roust up resistances to check gauges, the infamous gauge tester photo shows resistances.

c-3826-jpg-jpg.jpg


5...Consider replacing the gauge IVR with a solid state one form RTE or someone similar
6....Check over the ammeter / bulkhead connector condition. EVEN IF YOU do not bypass the ammeter, READ this article so you understand the how and why

Catalog
 
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Thanks for the replies...... I went out between rains showers and wow the smell from the oil pressure switch. I think the switch has burnt out..... more digging I think
 
No way for the oil pressure sending unit to "burn out". It's on the back end of the circuit, not the supply end. Power goes through the instrument cluster, warning lamp, and then back out to the sender on the engine. The sending unit is just a simple on/off grounding switch in a car with a warning light. Oil pressure keeps the switch open and the light off. Low or no oil pressure allows the switch to close and complete the circuit which turns the light on. I suspect you have some wires crossed somewhere if the sending unit is getting straight 12V without a load (like the light) further up the line somewhere.
 
I'm guessing I know why the light does not work then when the ignition is on the wire is permanently live.....
 
Which wire? If the sender wire becomes shorted/ cross connected to a live wire it will smoke the wire, likely, when the oil sender is closed (no oil pressure). If it smokes the sender instead, and smokes the sender open, it will cause the oil light to glow when the key is "off" and will cause the light to be dark when the key is "on."
 
I've looked at the back of the bulkhead and there wires cut off and taped up. It maybe a previous owner has connected the wrong wire. Ill have to search for a wiring diagram.
 
Hopefully everyone who's worked on the car in the past and present knows that it's wired for Negative Earth (ground), and not like earlier English cars that were Positive Earth. I've seen some knuckeheads over here make the opposite mistake on older English cars.
 
I've looked at the back of the bulkhead and there wires cut off and taped up. It maybe a previous owner has connected the wrong wire. Ill have to search for a wiring diagram.
Go to MyMopar and download the free factory manual. You may have to settle for Dodge vs Plymouth Also snare the 2 page 3rd party diagrams. These are not complete and do not show all connectors and options, but they can be easier to follow than the factory

You also might want to download the 72 manual from MyMopar. CAVEAT.....The 72 manual still has the older style "line" drawings, BUT THEY ARE DIFFERENT from 73 so you have to play "doublecheck." But they can be somewhat easier to decipher

In the 73 manual, go onwards on past the diagrams and look at the charts. Notice on the diagrams there are oval "windows" with identifying numbers. Such as "CI-2", "CE-5" whatever. The "I" is instrument panel, and the "E" is engine bay. The charts in the back then show those connectors

Here, EG from page 8-168, is the PC board connector

PCboard.jpg
 
Thanks for the inputs. What I thought would be quickish fix is going to take some reading, some sweating,drinking and cursing to put right.... I knew sort of it wasnt going to be straight forward when I saw the assortment of fuses that we fitted...
Thanks again ! PS great bunch of people on here
 
You didn't say if illumination or hi beam bulbs work. If the panel isn't grounded by the mounting screws to dash, none will work except park lamp. the bulb sockets have 2 tiny ears that hold them in place and against the circuit board. If a ear breaks off they wont work.
Oil sender wire is likely the only gray color wire in the engine bay. With the ignition switch is on you would see 12 volts coming through that bulb. Ground the wire and bulb comes on. And that sender can leak oil into the wrong part of it and die. Usually will leak oil to the outside of it when this happens too.
 
The high beam, parking brake and dash light all work. While the cluster came out the second time. The printed circuit was tested and all the lights worked. When I plugged it back in its the direction indicator lights and the oil pressure are not still working. Oh and mine does have the markers on the fenders as well and they do flash
 
The wire going to the oil pressure switch is .... blue.....
nope, blue is switched 12 volts. 73 model has electric choke assist. The ceramic cased controller for it did get a branch of the switched 12V blue in the same general area. Oil sender is gray, temp is violet/purple, alternator gets a branch of the blue and a green from voltage regulator.
 
Cheers for that info.... there is mistake no1 from someone previous putting the blue wire to the sender
 
Each of the turn indicator positions in your circuit board have a screw where they ground beside them. Odds that both of them are not providing a ground is kind of slim. Looking at post #12 above, I'll guess D9 and D10 tan and light green are directional. Without a wiring diagram I dont know where these branches come from.
 
Sorry to be a pain..... I went i. Search under the hood and found the correct grey wire cut off and taped up. I have repaired it and when connected to the switch no light... earth the wire light works. Faulty switch ? The indicators problem, I switched on the hazards and cluster lights work and they work when indicating right but, not right does that sound also like a switch fault ?
 
The indicators are simple spliced wires coming off the switch. Look at the TS switch connector coming out of the column. tan and light green I think. There should be two of each there someplace. One of each goes through the bulkhead connector, out to the lamps, and the other 1 of each goes up to the cluster. Far more likely to be the PC board connector, trace problems, or cluster sockets and lamps than anything else
 
If you ground the grey sender wire and the warning lamp works, it's a bad sender. Or wrong one. Lamp type sender is a small switch, with black insulated top, gauge sender is a larger can perhaps 2" in dia x 2" high

I spose in really bad conditions it's possible the passage to the sender is gummed/ packed/ plugged with hardened oil, but I've never seen that.
 
Sorry to be a pain..... I went i. Search under the hood and found the correct grey wire cut off and taped up. I have repaired it and when connected to the switch no light... earth the wire light works. Faulty switch ?
Refer back to post #4.
 
The indicators are simple spliced wires coming off the switch. Look at the TS switch connector coming out of the column. tan and light green I think. There should be two of each there someplace.
See thats the part that I didn't know or recall from my experiences. If the turn signal to car harness connector terminal couldn't accept 2 of a certain size wire they would put 2 wires in the bulkhead connector where larger terminals are and double back to the inst' panel harness with the turn indicator branches. First time I saw this was when the put reverse lamps on the radio fuse (1968). The wire added to radio connector went to bulkhead only so it could change colors.
 
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