Gauge help please !!!

[Chippa]

Guys,

I have tried to do some research on why my oil pressure gauge is pegged all the way while the other gauges seem to be ok....

That said i think the age factor is creeping in as every now and then i have witnessed the temp gauge spike up quickly and also the fuel gauge then both fall back down. I have pulled out the instrument cluster today, it doesnt appear to have had any of the wiring messed with from what i could see, all bar some one has bypassed/looped the spade socket on the dome /dimmer switch...

The voltage inverter (think thats what its called and capacitor ) are just a push fit into the circuit board is that factory or aftermarket??? crap setup lol !!! i have no idea 

Here is some pics, please help me try and determine what to look for and check.....any help is greatly appreciated

cheers Andrew 

[Chippa]

I dont know whether to continue pulling the cluster apart,clean the circuit board etc ,etc   i replaced the larger dome sender about 12 months ago and also when i hopped in her today and just turned the key to accessories the oil gauge also pegged out and the rest stayed normal (fuel slowly coming up)

probably didnt needed to go to the extreme of pulling it apart but hey us Moparians cant help ourselves sometimes 

[fy469rtse]

That bottom photo Chippa, the rectangle shaped plug in is your voltage reducer, gauges run on roughly 5 volts , it's just a set of contact points inside, very primitive, it could be that , check the pins aren't loose where your wiring plug goes on , that's another culprit,
Google RT speciality s or charger speciality s, they have modern boards with built in voltage reduction, or you can get the modern electronic voltage reducer to just plug in your board if all good, the cylinder shaped one is just a resistor for radio if I remember correctly,
Your not over doing it, gives you a chance to clean detail everything, polish the lense to gauges etc
The good news is your gauges function, and it's one of the above

[Chippa]

Yep !!! thats exactly what i have started to do  give it a good birthday while its out   being in Oz makes it a bit harder to go down the street to get the right part......

I'll see what i can dig up locally and interstate before i start looking online in the U.S but i dont like my chances

[fy469rtse]

I'm also here Melbourne,
Don't let the distance scare you off , those two company's are great to deal with , just set up a PayPal account , if you buy local your just buying off someone that's doing your sourcing for you, but expect to pay for that privilage,
I have bought many times of charger speciality s, while your on his site check out his parts and cool electric head light door openers

[hemi68charger]

Your board looks to be in great shape..........

I would get a new transistor voltage limiter ( modern versions ). If you aren't in a big hurry to put her back together and you have it apart, I would do the amp-2-voltage conversion by redlinegaugeworks..

Here's my thread when I almost lost my '69 Charger 500 due to the amp gauge shorting out on me ( weak link in a Mopar's electrical circuit ). From page three of the thread.

http://www.redlinegaugeworks.com/


http://www.dodgecharger.com/forum/index.php/topic,21155.50.html

Also, I would, if you haven't already, also get new sending units....... The oil pressure sending it readily available. Regarding the water temp sending unit, I would get a true Mopar version. I have found that the versions sold at the local auto parts store are unreliable....

[Pete in NH]

Hi,

On the oil pressure gauge the sender may be coming apart internally, engine vibration can catch up with them eventually or you have a short to ground along the wiring somewhere. Disconnect the wire from the sending unit, if the gauge goes back down the sending unit is bad , if not there is a short in the wiring.

If all the gauges peg and then go back do normal, that's a sign that the voltage limiter is beginning to fail. Sooner or later the contacts in it will stick permanently and burn out your gauges. While you have it all apart, replace the instrument voltage regulator. Either the RT Engineering electronic unit or one of the home made 7805 regulator replacements circuits.

[gibber]

Hi Andrew,

I rebuild these Mopar instrument clusters as a side hobby business. I would definitely replace that plug in voltage limiter with an IVR-4 from Real Time Engineering. Best solid state voltage limiter on the market IMHO. The thermal gauges (oil press, temp, and fuel) receive 5 volts from the limiter, and variable resistance from your sending units. Normally a pegged thermal gauge indicates the insulation has burned off the insulated nichrome wire that wraps around a bi-metal strip inside the gauge (altho it could also indicate a bad sending unit). Easy test is to take the sending unit wire off and then turn the key to ON. If the gauge doesn't move, try a new sending unit.

If it does still go full scale high with the sending unit wire disconnected, here is the probable explanation: With no insulation, the nichrome wire is grounded to the bimetal strip (not good) and the minute you power up the voltage limiter by turning the key to ON, the gauge reads zero ohms (no resistance) and the bimetal strip bends to full scale high. If the oil pressure gauge still goes to full scale after a replacement voltage limiter, the gauge will probably need to be replaced. I rewire those thermal gauges, but yours are available from a couple of sources as OE replacements and for 80 bucks, its cheaper than having someone rebuild the original.

Mark

[Chippa]

Thx for the replies guys 

At this point in time i cannot afford to replace the gauges, i only wanted to just replace the voltage limiter(even if its just OE style one),new globes, clean up the terminals etc and put back together...

The Alt gauge posts look to be in very good condition with no real signs of too much heat melting insulation on wires etc so im hoping all is well there even though its not the best design......if i do hook it all back up and the oil gauge still pegs out (testing by removing wire from sender) will this be safe to just leave as is until i can afford to replace???

One last question is it worthwhile applying some dielectric grease to any/all of the posts/connections to help aid/preserve current flow or just leave alone

once again thx for everyones input 

[TexasGeneral]

Don't know if this applies to your case or not but recently my gauges had started doing the same thing and other weird things going on with dash lights too.... Turns out my trusty toolbox in the trunk slid backwards (from all that bada$$ 383 torque ) and busted my tail lights out and was shorting things out.. Just something to check
.. Which reminds me.. If anyone has a decent set of 69 tail light covers they don't need.. Let me know

[fy469rtse]

Chippa ,
Whilst you have that cluster out , check out the wiring upgrades for these cars on here, it's a must do , Not Kidding, if your not handy with wiring get someone to help, but you were able to take cluster out , so you have skills
Amp gauge bypass a must , upgrade to volt gauge with correct face to look stock
look for bulk or firewall plug fixes, not expensive just fiddly and involves adding wiring and changing the way there wired
There's lots of factory mistakes and add ons overloading factory wiring especially now the wirings getting older,

[Chippa]

Lol have i opened up a can of worms now !!!!! i'm quite good mechanically but electrical is where i fall down, the age of the wiring does concern me but how far do i go with things....

Will try to do a bit more research then i guess, amp gauge bypass as mentioned etc wiring upgrades and see how where i end up

Cheers  Andrew 

[fy469rtse]

I was the same mate, good mechanically, had to teach myself the wiring, because no one was going to do the job as good as with the amount of time I would put in, plus I couldn't afford afford to pay someone to do it
Don't worry do a lot of reading on here , lots of good posts with detail and best part diagrams,
There's no such thing as a dumb question on here, just do it one step at a time,
We are here to help

[Dino]

You can do it Chippa!  I knew nothing about electrical until I started working on the Charger.  And now look!  I still don't know crap!   

Electrical is actually pretty hard to mess up if you follow a few simple rules, ie don't leave the battery hooked up and test continuity of your work before you put the juice to it.

I changed the charging system on my car and installed a bigger alternator.  I can draw you a schematic on how to do this if you like.  At a minimum I would suggest what others said: connect the black and red amp gauge wires to each other so the load is off the ammeter and install the IVR 4 solid state voltage limiter on the circuit board.  Your stock one is going out.  Mine went out right after I restored my gauges and it fried all three of them.

[Chippa]

Cheers Dino !!!!

Yeah i feel confident to work on my cars no matter what, but sometimes i start reading too much to absorb in one go (i have to know everything before i get stuck into it!!! OCD )

90% of the wiring in this car looks to be original and it doesn't have a booming sound system (just a CD player upgrade and some speakers ) charging system std etc from what i can see and looks untouched from behind the cluster so i think at this point in time i will probably just do the two basic upgrades (IVR-4 ...$50 bucks and 30 bucks postage to Oz sheesh!!) and join up the amp meter wires etc, but i will have a good look 2moz at the wiring take some more decent pics for you all to view incase someone picks up something weird.....

After all i would hate for my girl to catch fire after all the hard work i have put into her...like we all have

Cant thank everyone enough..thats why i love this forum cause we all like to help each other 

[Just 6T9 CHGR]

Good lookin ride there Chippa!

[Chippa]

Ok well true to form i cannot help myself so i have decided to go that little bit further and strip it all out,been online to PDD in Canada and other sites for prices.....while thats coming to Oz i'll be purchasing a airbrush kit,Alclad paints etc and starting on the bezel panels (Inspiration from Dino thread haha)

Couple of pics of me stripping it down my Amp gauge looks to be in pretty good nic.....there is a side of me that wants to just hook it all back up as it seems to be all ok but its probably a foolish risk..

So heres to one of my threads morphing into a much larger job as per usual.....will take pics of my progress cause we all love pics 

[Chippa]

Guys,

A simple question but i'm not sure....


I have found the chart that has the globes for the instrument cluster ( 6 x #57 and #158 ?? 10 globes in total).
Can some please tell me what wattage globes they are??

Just trying to get the equivalent here in Oz and want to know what to ask for

Thx in advance

Andrew 

[Pete in NH]

Hi,

Both the #57 and #158 are rated at 14 volts, .24 and 3.36 watts. The #57 is a BA9S base and the #158 is a T3-1/4 glass wedge base. These numbers are kind of universal and you might be able to find them just by type number.You can get a lot of information on them just by doing an internet search on the type numbers.