International Full Size Jeep Association
Home Forums Reader's Rigs Tech Library Trail Stories FSJ-List
International Full Size Jeep Association  

Go Back   International Full Size Jeep Association > Tire Kickin' > General FSJ Tech

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 06-01-2012, 09:59 AM
AMC80cherokee's Avatar
AMC80cherokee AMC80cherokee is offline
Member
 
Join Date: Nov 02, 2011
Location: Los angeles CA
Posts: 86
Talking Back to original gauges

Hi all! I am removing some aftermarket gauges from the top of my dash and trying to reconnect the original: oil pressure gauge, thermometer and etc. but I can't find of any these connections! does anyone know how the original oil pressure gauge works? because the aftermarket gauge has a hose (with oil) attached to it but I don't see any place on the original instrument cluster to connect a hose with oil...mine is a 1980 Cherokee WT.
Reply With Quote
  #2  
Old 06-01-2012, 10:16 AM
babywag's Avatar
babywag babywag is offline
out of order
 
Join Date: Jun 08, 2005
Location: Land of froot loops and cukcoo-nuts, CA
Posts: 9,659
The original gauges probably stopped working or are inaccurate.

Stock gauges are electric not mechanical, so no provision for the oil line.

You'll need to verify it still has the original sending unit and wiring connections on the engine.

Oil sender is by the oil filter and will have a single terminal for the original wire running to the cluster. Wire is blue IIRC.
Coolant sender is on the front driver's side of the intake manifold, again single wire connection, and wire is orange IIRC.

My advice is to keep the aftermarket gauges if they work.
__________________
Tony
Reply With Quote
  #3  
Old 06-01-2012, 10:46 AM
serehill's Avatar
serehill serehill is offline
Gone,Never Forgotten.
 
Join Date: Nov 22, 2009
Location: Mesquite Texas
Posts: 8,619
Well

Unless someone cut them off there4 should be a round & one rectangular plug in the wiring harness that plugs intto the dash. If he cut them off get a copy of the manual & have fun. Like previously stated Original gauges are not accurate. If you are not sure at this point what's happening it will be very difficut to figure it out.
__________________

80 Cherokee
360 ci 727 with
Comp cams 270 h
NP208
Edlebrock performer intake
Holley 4180
Msd total multi spark.
4" rusty's springs
Member, FSJ Prissy Restoration Association

If you can't make it better why waste your time. No use repeating the orignal mistakes. I'm to old to push it that's why.
Reply With Quote
  #4  
Old 06-01-2012, 11:17 AM
joe joe is offline
 
Join Date: Apr 28, 2000
Location: PNWet, USA
Posts: 22,392
You'll need the stock electrical sending units to run the stock gauges. The temp gauge has a CVR(constant voltage regulator) built into it to drop the voltage to the gauges. If your add-on gauges were installed because the temp gauge was bad I'd start with a brand new or at least a known working temp gauge. If the CVR is toast and the gauges get full 12V they'll all read wonky.
__________________
joe
"Don't mind me. I'm just here for the alibi"
Reply With Quote
  #5  
Old 06-01-2012, 06:21 PM
AMC80cherokee's Avatar
AMC80cherokee AMC80cherokee is offline
Member
 
Join Date: Nov 02, 2011
Location: Los angeles CA
Posts: 86
Angry

Thanks guys! the aftermarket oil pressure gauge seems to be working but the temp gauge and voltmeter are disconnected...now that I know the colour codes for the respective wires; I think I can figure it out. I have an original (rebuilt) instrument cluster so I wanna use that. besides, the gauges on top of the dash looks ugly! because he had to punch a hole in the top of the dash .

Thanks again!
Reply With Quote
  #6  
Old 06-01-2012, 06:26 PM
babywag's Avatar
babywag babywag is offline
out of order
 
Join Date: Jun 08, 2005
Location: Land of froot loops and cukcoo-nuts, CA
Posts: 9,659
oljeep.com should have a wiring diagram set and a service manual that's close enough to '80 to work for gauge testing, specs, etc.

'73-'85 mostly the same when it comes to the gauges.
__________________
Tony
Reply With Quote
  #7  
Old 06-01-2012, 06:37 PM
Rich88's Avatar
Rich88 Rich88 is offline
FSJ Maniac
 
Join Date: Nov 20, 2008
Location: Wilds of Ellington, CT
Posts: 4,182
Go here and scroll down to '80. http://oljeep.com/gw/elec/GW_wiring.html

Then go crazy & blind tracing wires from the sending units to the instrument panel plug to verify the correct wires & colors. See "8 cylinder" pages 1 & 2.
__________________
Jeepasaurus (Wagonus Grandi quadropedus)
88 GW 360-.030 over/2150/727/229/Posi, e-pump, AC (broke), tow package, Monroe Air Shocks, TFI, CTO-Free, AIR-free, oil & tranny coolers, dried knuckle blood all over, GM 350 TBI in a box, waiting...
"You're an FSJ'r when the parts guys memorize your name, phone & credit card#."
Reply With Quote
  #8  
Old 06-01-2012, 09:05 PM
Great Pharoah's Avatar
Great Pharoah Great Pharoah is offline
Master Mechanic
 
Join Date: May 07, 2002
Location: Horseshoe Bay, Texas
Posts: 763
Guages

an 80 did not have a voltmeter guage in the original instrument cluster, it had an ammeter and I would be wary of that, especially if you have an aftermarket alternator. Any problem at all with it will burn up your cluster, then your interior, and finally your whole ride. Stay with a volt meter. You can mount it under the dash, or get on of those housing and mount it on the winshield pillar. you can get those in 1, 2, or 3 guage pods. Or you could get on of those replacement instrument panels from BJs and mount what ever you like.
__________________
American Jobs should be for Americans.
Some Cheros run at 75, and some do 69,
But if I can get mine to start and run at all, I think I'm doing fine.

Big Mike
"Whoopi" 80 Cherokee Golden Hawk. 360/727/208
Horseshoe Bay, Texas
Reply With Quote
  #9  
Old 06-01-2012, 09:55 PM
AMC80cherokee's Avatar
AMC80cherokee AMC80cherokee is offline
Member
 
Join Date: Nov 02, 2011
Location: Los angeles CA
Posts: 86
Quote:
Originally Posted by Great Pharoah
an 80 did not have a voltmeter guage in the original instrument cluster, it had an ammeter and I would be wary of that, especially if you have an aftermarket alternator. Any problem at all with it will burn up your cluster, then your interior, and finally your whole ride. Stay with a volt meter. You can mount it under the dash, or get on of those housing and mount it on the winshield pillar. you can get those in 1, 2, or 3 guage pods. Or you could get on of those replacement instrument panels from BJs and mount what ever you like.

The ammeter is in the original cluster and works fine; accuracy within 10% of actual - I measured the current with another independent ammeter. The voltmeter is in the 3-gauge aftermarket cluster and I can live w/o it. My only real concerns were the oil pressure wire/connection back to the OEM cluster and the temp reading gauge...
__________________
1980 Jeep Cherokee - WT
1978 Chevy Nova - Rally
1986 SAAB 9000-T
2009 Chrysler Town & Country
2010 MBZ 350 E - AMG
2015 YUKON Denali


When you are ready to learn...close the books

Last edited by AMC80cherokee : 06-01-2012 at 09:58 PM.
Reply With Quote
  #10  
Old 06-02-2012, 02:24 PM
Tinkerjeep's Avatar
Tinkerjeep Tinkerjeep is offline
Banned
 
Join Date: Mar 01, 2009
Location: Redneck-populated Flyover Country, USA
Posts: 3,662
HOLD ON! you will hear all kinds of crap about stock gauges being garbage. and for most people who don't want to get fingers dirty or scratched up, that's true, (I mean jeez most are 20 to 40 years old now!!!)

HOWEVER. You can get a manual and volt/multi-meter and do some resistance checking. You will want to remove the instrument cluster and perform these tests. Each gauge has a resistance value for its connections. Ammeter is a different animal. But your temp gauge houses the Constant Voltage Regulator which steps incoming 12-14volts down to about 5.5-6volts. The Fuel, Oil pressure and Temp run off this 5.5 volts.

Here's the deal. you will likely need to clean oxidization off the copper contacts and possibly the pins on the back of the board. this will help lower resistance and will make your gauges perform as intended...if the gauges themselves are functional.

Oil pressure sending units are available for $20 to $60 and screw on to the front passenger side of the block on the end of a pipe.

Temp gauge sending units are smaller and go into the back of the Thermostat housing or on the water crossover on the intake manifold...not sure on price.

Fuel gauge sending unit is in fuel tank mounted to float arm. not sure on price.

All the above sending units are electrical and rely on resistance to indicate accurately.
Reply With Quote
  #11  
Old 06-02-2012, 02:31 PM
Lindel's Avatar
Lindel Lindel is offline
Perfesser of Jeepology
 
Join Date: Jun 15, 2000
Location: Carpentersville, IL 60110
Posts: 9,204
Quote:
Originally Posted by AMC80cherokee
The ammeter is in the original cluster and works fine; accuracy within 10% of actual - I measured the current with another independent ammeter. The voltmeter is in the 3-gauge aftermarket cluster and I can live w/o it. My only real concerns were the oil pressure wire/connection back to the OEM cluster and the temp reading gauge...

The issues with the ammeter is not it's accuracy, the issue with the ammeter is that it's a common cause of electrical fires in FSJ's. Not so much the ammeter as the 20+ year old wiring and the fact that people install bigger alternators or too many electrical devices.

A voltmeter won't have those issues, and will still tell you what you need to know about your electrical system without being a fire hazard. Far better to get the voltmeter and do the ammeter bypass.
__________________
Jeep Grounds
RRV Homepage
Texas Full Size Jeep Association
1987 Grand Wagoneer
AMC 360/TF727/NP229
1999 Wrangler Sport
4.0L/AX-15/NV231


Quote:
“Freedom is never more than one generation away from extinction” by Ronald Reagan.


Formerly of DFW/Gun Barrel City, TX - eventually to return...
Reply With Quote
  #12  
Old 06-03-2012, 02:40 PM
AMC80cherokee's Avatar
AMC80cherokee AMC80cherokee is offline
Member
 
Join Date: Nov 02, 2011
Location: Los angeles CA
Posts: 86
Thumbs up

Quote:
Originally Posted by Tinkerjeep
HOLD ON! you will hear all kinds of crap about stock gauges being garbage. and for most people who don't want to get fingers dirty or scratched up, that's true, (I mean jeez most are 20 to 40 years old now!!!)

HOWEVER. You can get a manual and volt/multi-meter and do some resistance checking. You will want to remove the instrument cluster and perform these tests. Each gauge has a resistance value for its connections. Ammeter is a different animal. But your temp gauge houses the Constant Voltage Regulator which steps incoming 12-14volts down to about 5.5-6volts. The Fuel, Oil pressure and Temp run off this 5.5 volts.

Here's the deal. you will likely need to clean oxidization off the copper contacts and possibly the pins on the back of the board. this will help lower resistance and will make your gauges perform as intended...if the gauges themselves are functional.

Oil pressure sending units are available for $20 to $60 and screw on to the front passenger side of the block on the end of a pipe.

Temp gauge sending units are smaller and go into the back of the Thermostat housing or on the water crossover on the intake manifold...not sure on price.

Fuel gauge sending unit is in fuel tank mounted to float arm. not sure on price.

All the above sending units are electrical and rely on resistance to indicate accurately.

I am in complete agrement regarding the gauges. Regardless of the original build-quality, after 20/30 years of use, a lot could begin to go wrong...so yes; I did find that cleaning the connections and especially tightening the GND tab/screw at the back the cluster, allowed all lights and gauges to function...as for acuracy of the critical readinsg like oil pressure & temp. meter, the temp. reading can be easily compared to an after market independent meter. I just felt that making the original cluster gauges work again (as they once did) was better than simply giving in and going aftermarket...THANKS for your help.
__________________
1980 Jeep Cherokee - WT
1978 Chevy Nova - Rally
1986 SAAB 9000-T
2009 Chrysler Town & Country
2010 MBZ 350 E - AMG
2015 YUKON Denali


When you are ready to learn...close the books
Reply With Quote
  #13  
Old 06-04-2012, 02:59 PM
Tinkerjeep's Avatar
Tinkerjeep Tinkerjeep is offline
Banned
 
Join Date: Mar 01, 2009
Location: Redneck-populated Flyover Country, USA
Posts: 3,662
and here's a funny thing I found out yesterday...like "funny as in HOLY CRAP!"

I have been pulling wiring harnesses of my various donor Jeeps for years, last night I was going through them to pick the best bits to build a 1985 in-cab wiring harness and fuse-block into one compatible to 1976 wiper switch and wipers and be compatible with late 1970s plug-ends. I found one 1979 Fuse blosk with the heavy yellow and red wires melted. I found a melted headlight switch connector. I've had a fan-motor switch melt while I was driving. Looking at all this stuff, and the fact that the Wagoneer body on my daughter's 1976 Truckoneer project had an underdash fire, I'm willing to put the blame on MORE than just the ammeter for causing electrical fires in these things.

Good wiring and gauges can go bad based on years of use/ improper ground or bad switches. Everyone's electric tailgate woes as well as other observances is testimony to the fact that "Made in America" does NOT always mean "Good".
Reply With Quote
  #14  
Old 06-04-2012, 03:17 PM
Lindel's Avatar
Lindel Lindel is offline
Perfesser of Jeepology
 
Join Date: Jun 15, 2000
Location: Carpentersville, IL 60110
Posts: 9,204
Wiring wasn't a Jeep high point, of that there's no doubt. Low quality wire, under-sized wire and marginal connectors are just a few issues with Jeep wiring, has been the case for years, before and still to come.
__________________
Jeep Grounds
RRV Homepage
Texas Full Size Jeep Association
1987 Grand Wagoneer
AMC 360/TF727/NP229
1999 Wrangler Sport
4.0L/AX-15/NV231


Quote:
“Freedom is never more than one generation away from extinction” by Ronald Reagan.


Formerly of DFW/Gun Barrel City, TX - eventually to return...
Reply With Quote
  #15  
Old 06-04-2012, 03:22 PM
Tinkerjeep's Avatar
Tinkerjeep Tinkerjeep is offline
Banned
 
Join Date: Mar 01, 2009
Location: Redneck-populated Flyover Country, USA
Posts: 3,662
yarp. I did notice considerably fatter wires in certain circuits in the 85 harness.
Reply With Quote
  #16  
Old 06-05-2012, 01:47 AM
MonsterZ's Avatar
MonsterZ MonsterZ is offline
Grease Monkey
 
Join Date: Nov 11, 2010
Location: Fairbanks, Alaska
Posts: 469
I am actually going through the same thing with my '75 in cleaning up wiring and connections. I have finally hit a point where I kinda just said "F-it!!", and I am pulling every piece of where, and electrical component out of the rig and replacing the entire harness with a brand new one from Painless. I know that I will have to re-use the original components, but I am getting the feeling that it is going to be so much simpler to deal with these now and essentially all at once even though it will be one circuit at a time than to patch in pieces as I need them. However, this DID just add a considerable amount of time to the build . All in the name of safe Jeepin', right?
__________________
'75 Wagoneer, bone stock, about to be a whole garage of parts. Tear down starts 3 March, 2012,
see how long it takes to put it back together....

'91 XJ, 3 in Rough Country lift, 33's, Rattle can paint job, roof rack and cheapo off road lights. Diffs and winch next
Reply With Quote
  #17  
Old 06-05-2012, 06:30 AM
710 Burner's Avatar
710 Burner 710 Burner is offline
 
Join Date: Jul 30, 2003
Location: Normal, Oklahoma
Posts: 8,684
Quote:
Originally Posted by AMC80cherokee
I am in complete agrement regarding the gauges. Regardless of the original build-quality, after 20/30 years of use, a lot could begin to go wrong...so yes; I did find that cleaning the connections and especially tightening the GND tab/screw at the back the cluster, allowed all lights and gauges to function...as for acuracy of the critical readinsg like oil pressure & temp. meter, the temp. reading can be easily compared to an after market independent meter. I just felt that making the original cluster gauges work again (as they once did) was better than simply giving in and going aftermarket...THANKS for your help.
Good for you. I went through my gauges recently and checked/adjusted for accuracy (such that it is) added a solid state VR and I did replace the Ammeter, but mine was working fine. I only replaced it so I could do a possible alternator upgrade.
__________________
Mark B. Jones

Quote:
Originally Posted by GrandWag&Prix
Actually, now that I think about it, that could be either awesome or really terrible.


'79 Cherokee Chief "Junaluska"
Reply With Quote
  #18  
Old 06-06-2012, 12:03 PM
Tinkerjeep's Avatar
Tinkerjeep Tinkerjeep is offline
Banned
 
Join Date: Mar 01, 2009
Location: Redneck-populated Flyover Country, USA
Posts: 3,662
Quote:
Originally Posted by 710 Burner
...and I did replace the Ammeter, but mine was working fine. I only replaced it so I could do a possible alternator upgrade.

I think this is a fair consideration, however as long as the alternator never has to charge more than the ammeter is limited to...remember the old alts were rated for a maximum 63 Amps... you should be fine. If your battery is crap, and you are running high-wat headlights, your heater blower on high, and wipers and you have a 90 or 110 or even a 140 amp Alternator going on that thing...you may find yourself toasting something.

I think most "ammeter-caused" fires are more owner neglect/old wiring/abuse caused fires.
Reply With Quote
  #19  
Old 06-06-2012, 12:42 PM
Rich88's Avatar
Rich88 Rich88 is offline
FSJ Maniac
 
Join Date: Nov 20, 2008
Location: Wilds of Ellington, CT
Posts: 4,182
Quote:
Originally Posted by Tinkerjeep
I think this is a fair consideration, however as long as the alternator never has to charge more than the ammeter is limited to...remember the old alts were rated for a maximum 63 Amps... you should be fine. If your battery is crap, and you are running high-wat headlights, your heater blower on high, and wipers and you have a 90 or 110 or even a 140 amp Alternator going on that thing...you may find yourself toasting something.

I think most "ammeter-caused" fires are more owner neglect/old wiring/abuse caused fires.

X2 on "ammeter caused" fires. However, the ammeter does not pass through and measure the full current being consumed by the vehicle loads. It only passes through & measures the difference between what the battery is providing and what the ammeter is charging. If you're running along and consuming say 50 amps, the gauge will not be deflected to 50 amps. It will only read anywhere from 1 to 3 amps, representing however much more the alternator is putting into the battery to keep it charged compared to the current the battery is providing all your loads. And the capacity of the alternator (63A or 140A) doesn't matter. The only time you should see a large swing on the ammeter is immediately after start-up for several seconds as the alternator replaces the charge expended by the battery from cranking the starter. And even then, maybe 10-15 amps at most.
__________________
Jeepasaurus (Wagonus Grandi quadropedus)
88 GW 360-.030 over/2150/727/229/Posi, e-pump, AC (broke), tow package, Monroe Air Shocks, TFI, CTO-Free, AIR-free, oil & tranny coolers, dried knuckle blood all over, GM 350 TBI in a box, waiting...
"You're an FSJ'r when the parts guys memorize your name, phone & credit card#."
Reply With Quote
  #20  
Old 06-06-2012, 01:38 PM
Tinkerjeep's Avatar
Tinkerjeep Tinkerjeep is offline
Banned
 
Join Date: Mar 01, 2009
Location: Redneck-populated Flyover Country, USA
Posts: 3,662
exactly right, the ammeter circuit measures CHARGE not usage. that's why i said if your battery is crap and you are running all this other stuff you can max out the ammeter and possibly overheat things. I've personally seen 30 amps charge indicated several times...never 60...but close to it for a brief instant.
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
The Woodgrain Comparison ... steamship General FSJ Discussion 31 06-05-2017 07:03 PM
Any advice on gauges to match 1969 era? zbethem General FSJ Discussion 2 11-02-2009 12:13 PM
TPI tech gauges Fiodh. Argus General FSJ Discussion 0 09-06-2009 06:35 PM
Back for more of the headaches! Mud Menace General FSJ Discussion 4 01-21-2009 08:35 AM
What did yall do with your gauges? rufus General FSJ Tech 16 12-29-2008 04:57 PM


All times are GMT -6. The time now is 05:08 AM.


Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
corner corner