Gauges: voltmeter & temp ?s

[Waggymcgee]

I would like a better temp gauge, perhaps with numbers at least. Curious if that is a hassle given the CVR in the temp gauge and the relation to the fuel and oil pressure gauges.
I am also taking precautions so I can have peace of mind about common fire triggers. I am going to put a voltmeter under the dash as I have bigger fish to fry with the time I can spend on Jeep. I assume I can simply disconnect and remove ammeter. I wonder if anyone else has done this and how you blacked out the open space.
Finally a random question....why do you think the air ducts have a bunch of carpet in them. Mice?? There appeared to be a birds nest or something with feathers inside the headliner so it’s just another weird day with the wag. Appreciate your thoughts.

[MysticRob]

I would like a better temp gauge, perhaps with numbers at least. Curious if that is a hassle given the CVR in the temp gauge and the relation to the fuel and oil pressure gauges.
I am also taking precautions so I can have peace of mind about common fire triggers. I am going to put a voltmeter under the dash as I have bigger fish to fry with the time I can spend on Jeep. I assume I can simply disconnect and remove ammeter. I wonder if anyone else has done this and how you blacked out the open space.
Finally a random question....why do you think the air ducts have a bunch of carpet in them. Mice?? There appeared to be a birds nest or something with feathers inside the headliner so it’s just another weird day with the wag. Appreciate your thoughts.

I can't help on the CVR or wiring aspects, but carpet in the air ducts certainly sounds like critters, unless someone laid it nicely in there for some unknown reason.

Might want to disassemble both electric fans and associated plumbing to inspect too. My heater core fan (on engine bay firewall) had a TON of leaves and crap in it, though neither the interior nor AC fan area had any critters. Also might want to blow out the side vents too! Be mindful of hantavirus and other things rodents can spread though! If you have things in the AC vents inside the vehicle, then it sounds like they nested around the AC evaporator too. That might suck...

Sounds like yours had a window down for quite a while if birds got into it!

[tgreese]

If you can find a temperature gauge that will fit in the panel, you can replace the CVR with a regulator chip 7805 or 7806. Easy, cheap. Search for those numbers and you'll find a lot of discussion here and at FSJNetwork. Or, if you leave the gauge in place and disconnect the temperature sender, the CVR will still work.

There is a Sunpro voltmeter than you can remove from its case put in the panel in place of the ammeter. I have this one in my J20.

https://www.amazon.com/gp/product/B00029JZXM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Again, search and you'll find old threads with more info.

Disconnecting the ammeter leaves the wiring in place. You'll still have all the charging current from the alternator going through the bulkhead connector, up to the dash, and back to the battery through the bulkhead. Lacking the ammeter and changing nothing else, you must connect the ammeter wires together or nothing will work - no instruments, no lights, no ignition. The simplest thing is to put both big wires on the same ammeter post, bypassing the ammeter and leaving the wiring in place. There is a sticky thread at the top of the forum with lots of discussion of this topic.

[Waggymcgee]

If you can find a temperature gauge that will fit in the panel, you can replace the CVR with a regulator chip 7805 or 7806. Easy, cheap. Search for those numbers and you'll find a lot of discussion here and at FSJNetwork. Or, if you leave the gauge in place and disconnect the temperature sender, the CVR will still work.

There is a Sunpro voltmeter than you can remove from its case put in the panel in place of the ammeter. I have this one in my J20.

https://www.amazon.com/gp/product/B00029JZXM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Again, search and you'll find old threads with more info.

Disconnecting the ammeter leaves the wiring in place. You'll still have all the charging current from the alternator going through the bulkhead connector, up to the dash, and back to the battery through the bulkhead. Lacking the ammeter and changing nothing else, you must connect the ammeter wires together or nothing will work - no instruments, no lights, no ignition. The simplest thing is to put both big wires on the same ammeter post, bypassing the ammeter and leaving the wiring in place. There is a sticky thread at the top of the forum with lots of discussion of this topic.

Thanks Tim for the reply. I had researched this weekend and come across your posts in the other fsj forum and figured I would take the 7805 route. Since this original post, I had put the temp gauge for the 73-84 in my 85. First time out and it would not turn off. I can not imagine how it is related or what I did under the dash when swapping them out. Could the wrong gauge cause that?

[tgreese]

According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.

You could also pull the filter jumper from the back of the panel and, with the key on or engine running, measure if the CVR-in still has 12V from somewhere.

[Waggymcgee]

According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.

You could also pull the filter jumper from the back of the panel and, with the key on or engine running, measure if the CVR-in still has 12V from somewhere.

Thanks so much Tim. I sent this to my mechanic. I am not messing with it anymore, as I am clearly ill equipped

[Waggymcgee]

According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.

You could also pull the filter jumper from the back of the panel and, with the key on or engine running, measure if the CVR-in still has 12V from somewhere.

You were absolutely correct Tim. Pulled out the temp gauge, it was fried and wag turned off like it should. Will move forward with 7805 transistor solution. Thanks again!

[MysticRob]

Hopefully that works out for you, Kerry.
I have a line on that front grille I need so will let you know how it works out.

[Waggymcgee]

Hopefully that works out for you, Kerry.
I have a line on that front grille I need so will let you know how it works out.

You looking for that final type grill? I might shoot over to Pasco today. the owner kind of hoards waggy and jtruck stuff. I will text ya if I come across anything. See if I still got it and can flirt my way into some parts. No shame in my game!!

[MysticRob]

You looking for that final type grill? I might shoot over to Pasco today. the owner kind of hoards waggy and jtruck stuff. I will text ya if I come across anything. See if I still got it and can flirt my way into some parts. No shame in my game!!

I ended up getting one in twin falls today. Just a small dent that I can hammer out in the lower left, but even the headlight buckets are in perfect shape on this new one. Only cost me a hundred bucks and a couple gallons of gas in the hybrid.

[Waggymcgee]

https://photos.app.goo.gl/cY6U4mb7ZpAXWQgr6

[QUOTE=tgreese]According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.




Hey Tim. Hoping you can answer a question for me. On the attached link you can see a picture of my cluster. I am curious about the two pins that have been soldered/connected. One of those lines traces to the fuel gauge and I am not sure the other. I have looked at other gauges and see for ‘Radio noise suppression’ and others have nothing there. It kind of has the look of something not done in factory. Any thoughts?

[tgreese]

According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.

[quote=Waggymcgee]https://photos.app.goo.gl/cY6U4mb7ZpAXWQgr6

Hey Tim. Hoping you can answer a question for me. On the attached link you can see a picture of my cluster. I am curious about the two pins that have been soldered/connected. One of those lines traces to the fuel gauge and I am not sure the other. I have looked at other gauges and see for

[tgreese]

According to the TSMs, the later gauges have a very different calibration from the earlier gauges. Have you looked at the parts books at www.oljeep.com? I would look there and see if the '85 gauge is different from '84, and whether the PNs the book calls out for your Jeep match what BJ's is offering.

The temp gauge has 4 connections: +12V in, ground (through the case), +5V (CVR out) and the temperature sender. The 12V comes from the ignition, so if that were being held high somehow, the ignition would not shut off. Possible there is a constant 12V trace on the board that is shorted to the gauge? Maybe you plugged in one of the connectors wrong? You could pull the panel out and measure voltages with the key off and engine running.

If you pull the panel out and run, be sure to ground the panel with a wire or clip lead or something, since the CVR needs a ground. Without a ground, the CVR will go 12V always, and you gauges won't last long with a constant 12V. Another good reason to bypass the CVR using the 7805; unlike the CVR, the 7805 will go to zero output if it loses ground.

https://photos.app.goo.gl/cY6U4mb7ZpAXWQgr6

Hey Tim. Hoping you can answer a question for me. On the attached link you can see a picture of my cluster. I am curious about the two pins that have been soldered/connected. One of those lines traces to the fuel gauge and I am not sure the other. I have looked at other gauges and see for Radio noise suppression and others have nothing there. It kind of has the look of something not done in factory. Any thoughts?

From memory only, that's where the radio suppressor goes. It's definitely a bodge, but likely ok. The suppressor is a choke as best I can tell, and a wire will work in place it. Though that admits ignition noise to whatever gets power from there.

You can look at the wiring diagram and figure it out. Not hard. Each of the connections on the pins is labeled on the diagram. The circle is keyed by the notch. Follow the trace from the pin to what it's connected to, and follow the line on the diagram. Easy peasy.

BTW looks like backquote is bad news for the forum software. Don't use them.

[Waggymcgee]

Thanks Tim. One last question. I have loose pins and I think my board likely needs retracing. Lookin at one that came out a 79 with voltmeter swap already done (yay). Anything I need to consider? Seems to me it should work fine. I am clearly gun shy after frying that temp gauge. I will still do the 7805 voltage regulator fix. Thanks again. I have learned a lot from you on both of these forums.

[tgreese]

Not sure what you mean by retracing. The pins often get loose. You can solder them back. I have repaired pins on one of my trucks by inserting a piece of solid copper wire in the center and filling the gaps with solder. I would not throw parts at this problem. From your picture, the board looks fine. A cluster with a voltmeter installed may or may not be a bargain, depending on the quality of the work. The clusters are all pretty much the same in this era, as I recall.