What's the best way to replace the Cluster Voltage regulator?
- Thread starter Dodgex2
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I pulled the cluster completely out to give it the once over. I tightened all the terminals. Only real issue I see is a corrosion on the head lamp switch. Am I missing anything?
Again should I have voltage on both sides on my amp meter? Seems I read I should not. Thanks, Matt
Again should I have voltage on both sides on my amp meter? Seems I read I should not. Thanks, Matt
NukeBass
Well-Known Member
Does your ammeter have a short in it? I pulled my cluster out a long time ago and am trying to remember how everything was wired (mine is a 73 Duster). I remember all the current coming through the firewall went to one side of the ammeter. I'm pretty sure there was another wire coming from the ammeter to one of the other terminals, too, since there isn't a copper lead coming from the ammeter.
You may want to spray some contact cleaner on your headlight switch while you have it out to clean up some of that corrosion. It gets the majority of the current coming from the alternator. Mine looked about that bad and hasn't caused a problem. I bought a replacement from Auto Zone, but my knob didn't fit (too short) and I didn't like any of the generic replacements so I took it back.
You may want to spray some contact cleaner on your headlight switch while you have it out to clean up some of that corrosion. It gets the majority of the current coming from the alternator. Mine looked about that bad and hasn't caused a problem. I bought a replacement from Auto Zone, but my knob didn't fit (too short) and I didn't like any of the generic replacements so I took it back.
NukeBass
Well-Known Member
I just pulled my 73 wiring diagram (it may be similar to yours) and it looks like all of the lamps are powered from the headlight switch. The ammeter looks to be the measurement between the alternator and the starter relay. All the actual cluster power comes from the alternator into the headlight switch (I could be reading this incorrectly, though). If your fuses are setup the same as mine, fuse 6 looks like it feeds all of the gages (not the ammeter), the oil lamp, the brake lamp, and some seat belt relay stuff.
The extra prong on the voltage limiter may be the ground for it. I don't remember where mine connected, but I think it just rested on the non-copper portion of the cluster.
When you get voltage on both sides of the ammeter, do you get positive on one and negative on another? The meter is setup to read "negative" amps (just a direction, I think) when the car is running on the battery and "positive" amps when the car is running off the alternator.
I suppose it could be a bad voltage regulator, but I don't know if it is common to blow a fuse if one goes bad. Three amps isn't a whole lot, though, when you consider your alternator is probably putting out more than 60 (if it is a newer one).
The extra prong on the voltage limiter may be the ground for it. I don't remember where mine connected, but I think it just rested on the non-copper portion of the cluster.
When you get voltage on both sides of the ammeter, do you get positive on one and negative on another? The meter is setup to read "negative" amps (just a direction, I think) when the car is running on the battery and "positive" amps when the car is running off the alternator.
I suppose it could be a bad voltage regulator, but I don't know if it is common to blow a fuse if one goes bad. Three amps isn't a whole lot, though, when you consider your alternator is probably putting out more than 60 (if it is a newer one).
73 should be about the same. I just checked the amp meter for power on both sides with a test light so I'm not sure. If all the power for the guages comes in from the headlamp switch then maybe my headlamp switch has a short causing the fuse to blow and guages and lights to not work? Is that what you're thinking? I hope it's that easy! lol
NukeBass
Well-Known Member
I actually looked over the diagram again and the lights come from the headlight switch, but the gages come from the alternator/battery through fuse 6 (these diagrams are confusing!!). The current does feed through the voltage regulator on the firewall, so if that is bad then it could cause an overcurrent, but it wouldn't fail overnight, I wouldn't think, since it was probably working before.
You could go crazy with this and start by pulling all of the light bulbs to make sure nothing is shorting to ground there. If you lose fuse 6, it traces back to losing power to the whole cluster, I think. Then maybe see if you can disconnect the gages one at a time to eliminate any grounding short there. Also check to make sure none of the harnesses have any connections touching and that all of the circuit boards are insulated (not going to ground). I'd hate for you to go buy a headlight switch and it not be the problem, though it would be nice if it was that simple.
You could go crazy with this and start by pulling all of the light bulbs to make sure nothing is shorting to ground there. If you lose fuse 6, it traces back to losing power to the whole cluster, I think. Then maybe see if you can disconnect the gages one at a time to eliminate any grounding short there. Also check to make sure none of the harnesses have any connections touching and that all of the circuit boards are insulated (not going to ground). I'd hate for you to go buy a headlight switch and it not be the problem, though it would be nice if it was that simple.
I did look at all the bulbs thought that might be it too, no luck they all look good. Also checked the connectors from the harness all looked good also. I just know this is probably something stupid and I'm just missing it. To bypass the guages because of the circuit board I guess I just have to remove them and see if the fuse stays intact. I hate electrical problems! Thanks for the help Nukebass. Matt
NukeBass
Well-Known Member
If you need me to, I can try to get under mine and see if I can get a couple of pictures of my connections tomorrow to make sure nothing was miswired or anything. Unfortunately, none of my books have a good diagram of what the wiring actually looks like back there.
Been looking at the diagram, your right very confusing. Far as I can make out the power comes to the guages and lights via the main harness connector I believe the 12 O'clock pin or #1 pin. Am I crazy? Matt
Thanks man but there is not much back there to miss wire. I downloaded a manual and I am studying now, hope I can get smart on this stuff. Thanks again for all the help, Matt
So if I disconnect the main connector on the cluster, replace my fuse turn ignition on and check for power at the #1 pin. If I have power there then my problem is on the cluster side, if I don't then it's on the harness side. Make sence? Matt
NukeBass
Well-Known Member
That sounds right to me. I finally found a key in one of my books that explains how everything is labeled and I think I understood it. Check your cluster connection at the Dark Blue wire (also lists a tracer, white?). I can't find a consistent orientation for the pin connector to know if it is at 1 or not, but dark blue seems to be the wire running from the bulkhead to the gages. I think the feed to the fuse comes from bulkhead connector N.
This may not be relevant but some may find it useful...
The round main harness connectors are keyed so they attach only one way. As far as I know every board ever made accepts that key in the 12 o'clock position.
When an engineer draws a schematic he might rotate that connector so the key is shown at 9 o'clock or anywhere he chooses. This is not to confuse the novice. It is only to simplify the drawing so it's easier to follow. My point being... the wire locations remain relevant to the key location regardless of that keys orientation on the drawing.
i had a IVR customer with all sorts of crossed circuit issues and we messaged back and forth for nearly 2 weeks before he mentioned that he was using a schematic to wire his connector.
In the end I felt his beer drinking was the reason for his misreading the schematic and my final statement to his was "It's 5 o'clock somewhere". LOL
The round main harness connectors are keyed so they attach only one way. As far as I know every board ever made accepts that key in the 12 o'clock position.
When an engineer draws a schematic he might rotate that connector so the key is shown at 9 o'clock or anywhere he chooses. This is not to confuse the novice. It is only to simplify the drawing so it's easier to follow. My point being... the wire locations remain relevant to the key location regardless of that keys orientation on the drawing.
i had a IVR customer with all sorts of crossed circuit issues and we messaged back and forth for nearly 2 weeks before he mentioned that he was using a schematic to wire his connector.
In the end I felt his beer drinking was the reason for his misreading the schematic and my final statement to his was "It's 5 o'clock somewhere". LOL
OK, tested power to pin #1 disconnected from cluster got 12V. Plugged back into cluster turned key on fuse blew. Removed connector and retested no voltage. So problem is in cluster.
Replaced fuse and disconnected head lamp switch, turned on key fuse blew. So problem is not headlamp switch.
Checked resistance on fuel guage 15 ohms. Did D cell test on gas guage and it did not move. So gas guage is bad.
Checked resistance on temp guage infinite. So temp guage is bad also.
My guess is one of these guages has an internal short causing the fuse to blow. Pulled both gauges to bypass still blowing fuse....ugh
Pulled all light bulbs still blowing fuse.
Anyone have any ideas? Would really appeciate some advice. Thanks, Matt
Replaced fuse and disconnected head lamp switch, turned on key fuse blew. So problem is not headlamp switch.
Checked resistance on fuel guage 15 ohms. Did D cell test on gas guage and it did not move. So gas guage is bad.
Checked resistance on temp guage infinite. So temp guage is bad also.
My guess is one of these guages has an internal short causing the fuse to blow. Pulled both gauges to bypass still blowing fuse....ugh
Pulled all light bulbs still blowing fuse.
Anyone have any ideas? Would really appeciate some advice. Thanks, Matt
NukeBass
Well-Known Member
I'll check and see what my gages are reading tomorrow afternoon. The infinite resistance is an open circuit, I think.
NukeBass
Well-Known Member
Both my gauges read somewhere between 10 and 15 ohms. I also have another cluster with a temp gauge reading around 15 ohms and an open fuel gauge (bad). I'll open the extra cluster up tonight and look at the gauges.
NukeBass
Well-Known Member
You can check the copper traces on the board to make sure they are not shorting anywhere. If they are shorting, I would think the copper should be visibly broken. Have you tried pulling the gauges and plugging it back in to see if the fuse blows? Since it is all one circuit, it could be possible something got knocked loose down stream of the cluster and is touching ground. Pulling the gauges would at least determine if there is an internal short in one of them.
Yeah I pulled them, still blowing the fuse. I checked for resistance from the limiter connector to the cluster housing and got .002 ohms. So looks like my short is in the circuit board. Do you know anyone who sells circuit boards and gauges? Thanks for the help. Matt
I know S&W gauges for pre 1970 Chrysler operate on a internal resistance of 20 ohms at 70 degrees. I bought the book on those.
I dont have the factory specs for later models but I've had enough experience with E-body gauges to know they aren't all the same. So.. I went to my 73 and checked the fuel and temp gauges. These are known working gauges and were fairly accurate. I got 14.2 ohms across that temp gauge and 13.6 ohms across that fuel gauge. The resistance in the nichrome wire changes with temperature and with condition after prolonged use. We can guess all day at what the original resistance was and what the allowable tolerance was. I can say + or = .5 ohms can be compensated for in calibration. Does any of this help? Probably not. You just want them to work regardless how exactly accurate they are.
Now whats blowing that fuse ? A couple of things that I have seen...
A loose connector pin on the board. Pushing the harness connector on pushes a pin inward a shorted to the housing. Pulling the connector away brings that pin back out to where it belongs so it looks like there isn't a problem.
Another fault is over tightening the attaching nuts on the gauge posts. Those posts have small square shoulders stamped into a fiberboard. The stamped tin nuts should serve as a warning sign to apply only minimal force but, one can apply enough force to draw the stud completely through that board. Result is dead gauge and possible short to the housing.
I dont have the factory specs for later models but I've had enough experience with E-body gauges to know they aren't all the same. So.. I went to my 73 and checked the fuel and temp gauges. These are known working gauges and were fairly accurate. I got 14.2 ohms across that temp gauge and 13.6 ohms across that fuel gauge. The resistance in the nichrome wire changes with temperature and with condition after prolonged use. We can guess all day at what the original resistance was and what the allowable tolerance was. I can say + or = .5 ohms can be compensated for in calibration. Does any of this help? Probably not. You just want them to work regardless how exactly accurate they are.
Now whats blowing that fuse ? A couple of things that I have seen...
A loose connector pin on the board. Pushing the harness connector on pushes a pin inward a shorted to the housing. Pulling the connector away brings that pin back out to where it belongs so it looks like there isn't a problem.
Another fault is over tightening the attaching nuts on the gauge posts. Those posts have small square shoulders stamped into a fiberboard. The stamped tin nuts should serve as a warning sign to apply only minimal force but, one can apply enough force to draw the stud completely through that board. Result is dead gauge and possible short to the housing.
Redfish, thanks for the info I'll check those items out. I have seen some clusters and gauges on ebay any other places that you know of to get them? Thanks, Matt
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