Oil presuure switch problem
Thread Starter
Instructor
Joined: Mar 2018
Posts: 128
Likes: 1
From: airmont new york
Oil presuure switch problem
Hey. 1984 c4
Oil presurre was showing eratic numbers so i changed harness and switch..once installed gauge pegged to 80..grounded tan wire gauge goes to zero...So gauge is good thought maybe new oil switch was bad so put old one back in..still pegged at 80..this is with key on but not started..took new harness back off and connnected wires with clips to switch..still shows only 80..Any ideas what to check next? New switch..new harness..ground tan wire shows zero..even tried grounding oil switch also..no change..This is a 3 prong sending switch next to distributor. ...Any ideas what else to check????
Thanx
Oil presurre was showing eratic numbers so i changed harness and switch..once installed gauge pegged to 80..grounded tan wire gauge goes to zero...So gauge is good thought maybe new oil switch was bad so put old one back in..still pegged at 80..this is with key on but not started..took new harness back off and connnected wires with clips to switch..still shows only 80..Any ideas what to check next? New switch..new harness..ground tan wire shows zero..even tried grounding oil switch also..no change..This is a 3 prong sending switch next to distributor. ...Any ideas what else to check????
Thanx
Last edited by gnj3963; Apr 6, 2019 at 04:23 PM.
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
GM gauges are pretty much the same 0-90 ohms 0 is low and 90 is high. Ground gauge signal wire the gauge will read low. Disconnect it, gauge reads high. Ohm reading of 45 gauge should be in the middle. If you ohm test sender with 1 connector of DVOM attached to ground the other to signal terminal of sender. With engine running what does meter read? Does it change between idle and 2500 rpm.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Thread Starter
Instructor
Joined: Mar 2018
Posts: 128
Likes: 1
From: airmont new york
After checking the ohms
Idle 600rpms reads 42-47
2500 rpms read out jumps anywhere from 50-100 erratically.
Im sure it shouldnt bounce around so much but gauge still pinned at 80..what i dont get is the gauge worked before sw.apping out sender.Im not a beginner
with cars..But this isnt making any sense..I really doubt the gauge in car quit the same time i swapped the sensor
Idle 600rpms reads 42-47
2500 rpms read out jumps anywhere from 50-100 erratically.
Im sure it shouldnt bounce around so much but gauge still pinned at 80..what i dont get is the gauge worked before sw.apping out sender.Im not a beginner
with cars..But this isnt making any sense..I really doubt the gauge in car quit the same time i swapped the sensor
Le Mans Master
Joined: Sep 2013
Posts: 6,192
Likes: 750
From: near the thumb in the mitten
Try a mechanical oil.pressure gauge see what it reads. Reading at 2500 should be stable at.pressure oil pump is rated at, probably 60 psi. What grade of oil are you using?
Thread Starter
Instructor
Joined: Mar 2018
Posts: 128
Likes: 1
From: airmont new york
Mobil 1 full syn. 10/W30...I'm
The car has only 88,000..It runs near perfect. Ive rebuilt 80% of it over the last 2 years..Im sure its not the oil pump.
What i did do is set up a part exchange with rock auto for the oil switch..Just to rule that out..I will get back near end of week after the replacement comes..
Thanx for the help!
The car has only 88,000..It runs near perfect. Ive rebuilt 80% of it over the last 2 years..Im sure its not the oil pump.
What i did do is set up a part exchange with rock auto for the oil switch..Just to rule that out..I will get back near end of week after the replacement comes..
Thanx for the help!
Team Owner
Joined: Sep 2003
Posts: 25,393
Likes: 2,741
OP - I believe you've mentioned a purchase from RA that 'rattled' they shipped first what brand and part #? The second from them was what brand and part #? I don't buy from RA and don't recommend them either! A mechanical gauge and capillary might be next BUT then how many $$ to spend to get a quality piece? I doubt the installs are an easy reach.
I'd consider maybe pressurizing a tank of some sort and maybe confirming operation of what you bought and maybe a 'local' purchase under a controlled environment before the install. You also mentioned erratic as an excuse for replacement. The most recent seems to do the same. A bad A/D converter in the dash seems maybe certainly a possibility.
This will be a 3d RA sender?
Maybe buy and check using a 100Ω potentiometer - I'd think that is maybe the least expensive check of the cluster & A/D converter.
I'd consider maybe pressurizing a tank of some sort and maybe confirming operation of what you bought and maybe a 'local' purchase under a controlled environment before the install. You also mentioned erratic as an excuse for replacement. The most recent seems to do the same. A bad A/D converter in the dash seems maybe certainly a possibility.
This will be a 3d RA sender?
Maybe buy and check using a 100Ω potentiometer - I'd think that is maybe the least expensive check of the cluster & A/D converter.
Last edited by WVZR-1; Apr 7, 2019 at 09:54 PM.
Thread Starter
Instructor
Joined: Mar 2018
Posts: 128
Likes: 1
From: airmont new york
The original sender that was in the car when i bought was going to b changed..The part i bought from Rock was an Acdelco..That rattled so i sent it back without installing..The one im working with now is the replacement..
If the next one does not work i will start lookung at the cluster..And i will check with a mechanical gauge
If the next one does not work i will start lookung at the cluster..And i will check with a mechanical gauge
Last edited by gnj3963; Apr 7, 2019 at 10:31 PM.