Rally dash oil pressure gauge issue.

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Gage should have gone to High with 10 ohms.
OTH it also should have gone to high with the sender at 10 ohms.
The ohm measurement of the sender doesn't make sense. Was the harness wire attached to the sender when you made the measurement?
 
Solder should have improved what was a only a crimp connection pin to board. The male pins are round but the female terminals are oval shaped. Never was a lot of contact anywhere. New aftermarket boards are pretty, have soldered pins, but their pins are shorter. Thus you loose a little bit of contact. I'm going to place my bet on bad gauge. If the fiberglass insulation on the ni-chrome winding is cooked, and/or the beam has a bow at room temperature, zero resistance can make the gauge do what within the 80-10 range will not.
 
Mattax said:
Gage should have gone to High with 10 ohms.
OTH it also should have gone to high with the sender at 10 ohms.
The ohm measurement of the sender doesn't make sense. Was the harness wire attached to the sender when you made the measurement?
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No just the sender in between ohmmeter and ground.
 
If the guage is bad why is it moving to almost half with a 10 ohm resistor but not at all with the sender at 10 ohms? It isnt so much accuracy at this point I am trying to get the thing to move. I would think its resistnace sensitive, at this point I can pull the connector and check resistance on the gray wire, but into the PC board not so much. i am wondering what its seeing at the gray wire from the sender.
 
You could have grounding issues. Keep in mind that an ohmmeter uses a very low current to measure the resistance. This can fool you on wiring harnesses.
 
Mike69cuda said:
You could have grounding issues. Keep in mind that an ohmmeter uses a very low current to measure the resistance. This can fool you on wiring harnesses.
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Thats a good point do you knw where the instrument panel ground is? as for now I do know my temp and electical guage work, fuel I dont have an idea as I am running engine off a gas can. it did work when I had it on the road though,actaually all the guages worked LOL! I may have to pull the cluster again. I really dont want to but. If it is the guage I may do the modern conversion of all of them I had heard the voltage limiter can cause a fire.
 
Dartswinger70 said:
No just the sender in between ohmmeter and ground.
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See that's what I'm saying makes no sense.
Whether it was by installing a resistor or getting resistance through the sender, 10 ohms should have had the same result on the gage with the engine running.
Could be a poor connection either at the attaching terminal or in the ground.

Yes you could bench test the gages (and the IVR) with the instrument panel out and connected to a battery.

IVR causing a fire??? AFAIK only if they've been messed with. Search for Redfish's posts about safe and less safe ways people repair, modify and disable.
 
Mattax said:
See that's what I'm saying makes no sense.
Whether it was by installing a resistor or getting resistance through the sender, 10 ohms should have had the same result on the gage with the engine running.
Could be a poor connection either at the attaching terminal or in the ground.

Yes you could bench test the gages (and the IVR) with the instrument panel out and connected to a battery.

IVR causing a fire??? AFAIK only if they've been messed with. Search for Redfish's posts about safe and less safe ways people repair, modify and disable.
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Thanks I will . I just want to go back over that PC board. One of the pins was "broke" and I resoldered it. Its still solid though unless it is somehow grounding through the metal in the cluster but that doesn't explain why the guage moves with the 10 ohm resitor. I dunno electrical is weird sometimes, ya wiggle this jiggle that and it starts working LOL!
 
When I repaired one of those pins I used a brass brad in from the back.
Not sure I posted pics. Lemme look.
edit An escutchean pin not a brad.
Here in this post How do I replace these metal pieces from my instrument panel?
The solder is just visible in this photo
upload_2021-5-13_16-8-17.png


There's a video I posted testing the IVR with a car battery and an analog meter.
Used aligator clips and resistors to test the gages.
I think its in Steve's rally dash redo thread.
edit:
Fried gauges?

and this one has good info
Test IVR
 
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I think you may have two problems here:

1. The gauge reads half scale with 10 ohm connected at the tank. This indicates that there is a fault in the wiring or gauge probably. Could be extra resistance somewhere, or a bad gauge.

If you temp gauge is working, your IVR is probably ok.

2. The fuel tank sender, which reads 10 ohms with a meter, gives a 1/4 scale reading. It should read the same as the 10 ohm resistor. This likely means you have a bad ground on the tank, or a bad connection to the tank.

The above assumes I have stated your test results accurately.
 
Currently this is what I have going on, the oil and fuel guages dont work, the temp and ammeter work. I cleaned all the contacts on the printed circuit board,cleaned the bulkhead connector and put the das back together, I did see that my brake warning light pulsates kindof liek the 5v oil sender pulsation, i dont thingk its from the turn signal flasher. So more issues to contend with. iam ablut ready to order mew guages and PC boards,getting tired of taking this thin g apart and ptuuing it bacl together.
 
Dartswinger70 said:
Currently this is what I have going on, the oil and fuel guages dont work, the temp and ammeter work. I cleaned all the contacts on the printed circuit board,cleaned the bulkhead connector and put the das back together, I did see that my brake warning light pulsates kindof liek the 5v oil sender pulsation, i dont thingk its from the turn signal flasher. So more issues to contend with. iam ablut ready to order mew guages and PC boards,getting tired of taking this thin g apart and ptuuing it bacl together.
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You may have missed 1 electrical contact. Because the limiter is inside the fuel gauge that gauge can has a slither of metal on its backside that grounds it to the inst' housing. I don't know if that is your problem.
I know faulty limiters do strange things at gauges, and since it is on the same 12 volt supply as the system voltage regulator a fault in the limiter could effect that regulators operation. So the pulse you see at brake warning lamp could be present throughout the cars electrical.
I agree this rally panel is a chore to R&R. I won't put one back in until I've installed a solid state IVR, a ground wire, all new light bulbs, everything I can do, and bench tested everything. Then if it doesn't preform in the car, I know the fault is in the car.
 
I built a sender simulator that you can use to test oil gas & temp gauges & wiring. Hook it up in place of your sender. It has zero, half, & full switches. I can send it to you in a small flat rate box if you need it. Just pm me your address. Just send it back when you are done.

4F08B489-BBD9-4C3B-8C0D-8A9BE0CF177B.jpeg
 
You've got some very knowledgable elec gurus giving you advice. Only thing I can add is i would get your boards refurbished if at all possible. I had these ones done and very happy. Not installed yet tho...:rolleyes:
We went with a triple gauge set that mounted directly below AC diffuser as well as orig gauges left in dash for 67 Barracuda. Work and look perfect, dont look out of place at all.

20211012_095605.jpg


20211012_095644.jpg
 
4spdragtop said:
You've got some very knowledgable elec gurus giving you advice. Only thing I can add is i would get your boards refurbished if at all possible. I had these ones done and very happy. Not installed yet tho...:rolleyes:
We went with a triple gauge set that mounted directly below AC diffuser as well as orig gauges left in dash for 67 Barracuda. Work and look perfect, dont look out of place at all.

View attachment 1715804518

View attachment 1715804519
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Who did The refurbish?
 
One thing I havent mentioned, I do not have the bulkhead connector that runs to the wiper motor and trans revers switch connected. Also the headlights and tail lights arent wired up. I dont know if this has anything to do with it, but I have thought that I should wire every thing up and see what I got going on. It seems like everything worked before in fact the car always amazed me because it didnt have any or many electrical issues. I have owned other Mopars where the wiring issues at the dash were atrocious. hat pulsing brake light kinda had me a little tense last night i was like "now WTF...":)
 
Dartswinger70 said:
One thing I havent mentioned, I do not have the bulkhead connector that runs to the wiper motor and trans revers switch connected. Also the headlights and tail lights arent wired up. I dont know if this has anything to do with it, but I have thought that I should wire every thing up and see what I got going on. It seems like everything worked before in fact the car always amazed me because it didnt have any or many electrical issues. I have owned other Mopars where the wiring issues at the dash were atrocious. hat pulsing brake light kinda had me a little tense last night i was like "now WTF...":)
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No, That 3rd connector in the bulkhead was called wiper connector for several years, only because there were no other wires/circuits in it. When the reverse lamp switch moved from inside the cabin to at the trans' the factory took advantage of previously unused ports of that connector.
Anyway... It shouldn't have any effect on gauge operation.
 
RedFish said:
No, That 3rd connector in the bulkhead was called wiper connector for several years, only because there were no other wires/circuits in it. When the reverse lamp switch moved from inside the cabin to at the trans' the factory took advantage of previously unused ports of that connector.
Anyway... It shouldn't have any effect on gauge operation.
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thanks I was looking at the wiring diagram and thought ill wire that up and see whats whatbut if it is isolated from the rest of it. I cant get over that brake light pulsing...its like the 5 volt signal to the oil sender not a turn signal flasher. Chances are i need a guage but i may need the boards also. What do you guys thing of the upgrade guage kits from herbs?
 
Dartswinger70 said:
thanks I was looking at the wiring diagram and thought ill wire that up and see whats whatbut if it is isolated from the rest of it. I cant get over that brake light pulsing...its like the 5 volt signal to the oil sender not a turn signal flasher. Chances are i need a guage but i may need the boards also. What do you guys thing of the upgrade guage kits from herbs?
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I spent 8 years renewing these OEM thermal gauges, repairing damaged boards, etc.., for other owners. Then the aftermarket found they could advertise their offerings and and collect twice the coins for made in China/wherever. So I retired. I don't know anything about aftermarket replacement gauges, except for one member who paid about 4 hundred for those gauges and said he is happy with them. Are they the same basic thermal range indicators? Do they operate on 5 volts or 12 volts? Regardless... Are they available today? Good luck whatever path you chosse.
 
I was playing around with my "round connector" tonight. Somehow it dawned on me the brake light pulsing was the oil wire on the wrong pin. I'm not sure how that happened but now I am looking for the wiring diagram for the round connector. Fun way to spend the evening. :)
 
Make sure you get the correct one, I believe the wire orientation changed thru the years.
Dartswinger70 said:
I was playing around with my "round connector" tonight. Somehow it dawned on me the brake light pulsing was the oil wire on the wrong pin. I'm not sure how that happened but now I am looking for the wiring diagram for the round connector. Fun way to spend the evening. :)
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4spdragtop said:
Make sure you get the correct one, I believe the wire orientation changed thru the years.
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I used one from 69 barracuda. somehow I think did have the oil wire on the brake light which explains the pulsing. I switched them around,and the brake light is out and I have the pulsing at the sender, but gauge still dead. The wiring diagrams can throw you off as the drawing looks like you are looking straight at the round connector, but it really is from the rear.I'm starting to thing bad oil gauge. I will chase after the fuel gauge next. Its strange though I do not remember taking that round connector apart.
 
So as you know I was at it last night after work. I did have wires switched in the round connector at the dash which explains the "pulsing brake light".
At the same time I did not have pulsing voltage at the oil sender wire under the hood. I found a wiring diagram from a 69 Barracuda which straightened the round connector out. I still have some issues to work out, like the fuel gauge and the high beam and brake light etc. I want to find out all that doesn't work and go from there. I am convinced my oil pressure gauge is gooched, and that is probably from installing the non rally dash idiot light sender in stead of the rally dash oil gauge sender previously. right now, my temp gauge and amp gauge work so that is a plus. I just wanted to post this current situation explanation for folks to learn, I do think the main reason the oil gauge is toast is because of installation the wrong sender. Now I am wondering does anyone know of a way to repair it or someone to send it out to? Or someone who may have a used oil pressure gauge for these dashes? I am torn between getting an autometer oil gauge or that gauge upgrade from Herbs parts,but would probably just like to have the original style dash and gauges. There isnt much on these by way of internet search. there is alot more B and E body dash stuff.
 
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