Home page
  Home Page   Contact Us   Our History   Advertise with Us   Sponsor List   Link to Us   Compare Levels   Member Agreement   Privacy Policy   About C3VR
  Community Forums   Active Threads   Forum Search   Top Posters List   Private Messenger   C3VR Email System   C3 Corvette Quiz
  Members Vettes & Pictures   Member Stories   Member Stats   Real Time Member Map   Member Search   Lifetime Member List   Member Calendar Entry Form   Who's Online
  C3 Registry Data   C3 Corvette Statistics   C3 Corvette Tips & Tricks   C3 Corvette How-Tos   Corvette Club Listing   Corvette Event Listing   Mechanic Directory   Corvette VIN Decoder   Save the Wave   Corvette Emblem History   C3 Corvette Birthday Calculator   C3 Corvette Build Dates   Corvette Parts Illustration Catalog   Shark Bytes - Online
  C3 Corvette Parts Auctions on eBay   Corvette Books   C3VR In-Stock Apparel & Accessories   C3VR Member Name Badges   C3VR Custom Apparel & Accessories @ Zazzle   C3VR Window Stickers   C3VR Member Deals & Discounts   C3VR Member Calendars   Shop Amazon.com
☰
SPONSOR AD SPONSOR AD

Topic: 72 Gas tank sending unit impedence values

in Forum: C3 Electrical


Already a Member? Click Here to Login

72 Gas tank sending unit impedence values

Posted: 11/9/06 1:28pm Message 1 of 5
windrider1200
Gold MemberGold Member
Send PM
Clifton, NJ - USA
Joined: 10/3/2003
Posts: 129
Vette(s): 1972 Coupe Ontario Orange Black leather interior LS-5; Turbo 400

Anyone know what the range ( empty to full ) of impedence is for a 72 gas tank sending unit?

BB NJ Ken




1972 T Top 454; "Boomer" Latest "upgrades": 1 1/8" front Stabilizer bar. Rebuilt SS calipers with O-ring pistons. Under car Chambered exhaust. Fiberglass rear spring (360lbs/in). Bilstein Rear Shocks. 3/4" Rear Stabilizer Bar. Tow hitch. Performer manifold with 600 cfm Holley. Comp Cam 262 .499 lift. L-88 Hood in process

SPONSOR AD:: (Our Sponsors help support C3VR)

72 Gas tank sending unit impedence values

Posted: 11/9/06 8:19pm Message 2 of 5
Profile Pic
Adams' Apple
Lifetime MemberLifetime Member
Moderator
Send PM
Duncanville, TX - USA
Joined: 11/8/2003
Posts: 20214
Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Uh...low to high? LOL
 
This is a question I don't think I've ever heard! So...I went & checked the service manual...no luck...it says to "test with a known good unit"(sender)!!!  Confused 
 
If you have a multi-meter set to ohms, it should have a full sweep, from infinity to 0, I would think. I've never actually checked the resistance numbers...just that it makes a full sweep.
 
Are you having problems with your gauge?



Joel Adams
C3VR Lifetime Member #56    
My Link


(click for Texas-sized view!)             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

72 Gas tank sending unit impedence values

Posted: 11/10/06 7:36am Message 3 of 5
windrider1200
Gold MemberGold Member
Send PM
Clifton, NJ - USA
Joined: 10/3/2003
Posts: 129
Vette(s): 1972 Coupe Ontario Orange Black leather interior LS-5; Turbo 400
Not really. I'm getting ready to order some aftermarket gauges to replace the factory ones. The oil press gauge doesn't work, and I find ammeters much less informative than voltmeters. Anyway,  the gauge bezel in my car now is cracked at the usual place,  it will need replacement eventually. So, for the time being, I don't mind hacking up the old one for aftermarket gauges and a DIN radio.  I'm looking at the Z series Autoguage line. 


1972 T Top 454; "Boomer" Latest "upgrades": 1 1/8" front Stabilizer bar. Rebuilt SS calipers with O-ring pistons. Under car Chambered exhaust. Fiberglass rear spring (360lbs/in). Bilstein Rear Shocks. 3/4" Rear Stabilizer Bar. Tow hitch. Performer manifold with 600 cfm Holley. Comp Cam 262 .499 lift. L-88 Hood in process

72 Gas tank sending unit impedence values

Posted: 11/14/06 5:22am Message 4 of 5
luft 1
Former Member
Send PM
Mesquite, NV - USA
Joined: 10/24/2005
Posts: 16
Vette(s): 82
About your gas sending unit the ohms are as follows 0 ohms=empty... full tank ohms reading 84-88 ohms= full. And then of course what ever between those reading is what is left in the tank. With the guage wire disconnected it should slowly go to full, with grounded should read empty, just to verfy correct guage operation.
Steve.



72 Gas tank sending unit impedence values

Posted: 11/23/06 6:53pm Message 5 of 5
Profile Pic
kstyer
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
Those are good numbers.
 
And an open circuit will cause the gauge to read above full.  You can go to Radio Shack and get a range of resistors to test the gauge reading.
Or short the wire to the tank, get a zero reading, leave it open and have the gauge go past full, and then put a test light in line and read somwhere between 1/4 and 3/4 tank, depending on the test light.
 
If it passes those test, put in a sending unit,  If it responds but won't operate as described, repair the gauge or check for high resistance in the wires.  
You can repeat these test at the gauge itself to eliminate the wires.   Now if there is a good power and ground to the gauge and the resistances still won't make it operate correctly, replace the gauge.
 
Don't forget to make sure the sending unit has a good ground before doing anything else.   A bad ground is a very common problem.
kstyer2006-11-23 18:54:30


in Forum: C3 Electrical


SPONSOR AD: (Our Sponsors help support C3VR)