My oil light blinks on and off - Vintage Mustang Forums
 1Likes
  • 1 Post By GypsyR
 
Thread Tools
post #1 of 10 (permalink) Old 03-25-2019, 09:58 PM Thread Starter
Senior Member
 
Join Date: Oct 2009
Location: far east north corner of Texas
Posts: 6,364
Garage
My oil light blinks on and off

This is probably a totally dumb question but when I turn the key on and while I am waiting for my o2 sensor to heat up, the oil pressure light(65) flashes on and off. Is it ahposed to be doing this and if so, is it the actual sending unit that is doing this? I seem to recall feeling my unit(LOL) and it felt like it was the sender that was actually doing the blinking.


65 2+2, 331, C4 presently apart for complete a restore
1979 Ford F150 custom, 302, C4, AC, tilt wheel, main transportation
macstang is online now  
Sponsored Links
Advertisement
 
post #2 of 10 (permalink) Old 03-25-2019, 11:29 PM
Senior Member
 
kenash's Avatar
 
Join Date: Dec 2006
Location: Severna Park, MD
Posts: 5,829
Garage
What is the action of the light after the 02 sensor is fully warm? So, is the 02 feeding an AFR gauge?

Ken ..
64 1/2 Poppy Red Cvt. Resto-Mod
333 Cu.in. T5z, 3:55, Dual 40 mm DCOE Webers
Performer RPM, CI cam, TFS/TWs, Tri-Ys, Discs w/Shelby Drums
Maryland
kenash is offline  
post #3 of 10 (permalink) Old 03-26-2019, 01:59 AM Thread Starter
Senior Member
 
Join Date: Oct 2009
Location: far east north corner of Texas
Posts: 6,364
Garage
Quote:
Originally Posted by kenash View Post
What is the action of the light after the 02 sensor is fully warm? So, is the 02 feeding an AFR gauge?

The oil pressure light will flash on and off until I crank up the engine and then it goes out. The o2 goes to my AEM analog gauge. With the key on you have to give it a few seconds to warm up the o2 sensor. The gauge has a red led indicator that goes out when it is good to go.


It has flashed on and off like this for a long time but I don't remember if it has always done this or not. It doesn't seem to be affecting anything. Turn signals work fine and I don't hear the telltale click of the relay. It really does feel like the clicking is inside the sending unit.


I just installed the new alloy engine wiring harness but the under dash stuff is the same as it was. I guess it is possible somebody rigged it somehow but I don't really want to go digging up under the dash to try and find it.


65 2+2, 331, C4 presently apart for complete a restore
1979 Ford F150 custom, 302, C4, AC, tilt wheel, main transportation
macstang is online now  
 
post #4 of 10 (permalink) Old 03-26-2019, 06:08 AM
Senior Member
 
66Ccode's Avatar
 
Join Date: Aug 2018
Location: NJ
Posts: 329
Honestly I would not wait to heat up your O2 like that cause any condensation that may get to the O2 will crack the porcelain and will cause it not to read correctly or fail...IMO
66Ccode is offline  
post #5 of 10 (permalink) Old 03-26-2019, 10:16 AM
Senior Member
 
kenash's Avatar
 
Join Date: Dec 2006
Location: Severna Park, MD
Posts: 5,829
Garage
I agree, why wait before firing up the engine? It doesn't serve any useful purpose. The sensor will heat up very quickly on it's own and your AFR gage's accuracy will not suffer. You want the temp to rise quickly. If you run a Pertronix kit, you can actually damage it, depending on the generation. Points can be damaged too. Just fire it up a go.......

Ken ..
64 1/2 Poppy Red Cvt. Resto-Mod
333 Cu.in. T5z, 3:55, Dual 40 mm DCOE Webers
Performer RPM, CI cam, TFS/TWs, Tri-Ys, Discs w/Shelby Drums
Maryland
kenash is offline  
post #6 of 10 (permalink) Old 03-26-2019, 10:51 AM
Just some guy
Supporting Member
 
GypsyR's Avatar
 
Join Date: Jun 2001
Location: SC foothills, USA
Posts: 18,678
Garage
Curious as to why you are warming it up also. You aren't going to get any meaningful readings from it until the engine is also at least somewhat warmed up too.

Since the oil sender does nothing but ground, I think I'd be looking on the positive side of the system in the cluster. If you had gauges doing the same thing I'd say it was the instrument cluster regulator, but with just the light and a bunch of aftermarket wiring I don't even know. I believe it's safe to say what it is doing or not doing while the engine is not running isn't really significant.

Last edited by GypsyR; 03-26-2019 at 10:57 AM.
GypsyR is online now  
post #7 of 10 (permalink) Old 03-26-2019, 11:17 AM
Senior Member
 
awhtx's Avatar
 
Join Date: Sep 2011
Location: The Hill Country of Central Texas
Posts: 8,434
The sending unit for an oil pressure light is nothing but an on/off switch. It is Normally Closed which illuminates the light and when the oil pressure reaches approximately 5 psi the switch opens and the light extinguishes. If your oil pressure light is turning off and on with the engine not running the power going to the sending unit must be connected to the constant voltage regulator or to the turn signal!
awhtx is offline  
post #8 of 10 (permalink) Old 03-26-2019, 06:42 PM Thread Starter
Senior Member
 
Join Date: Oct 2009
Location: far east north corner of Texas
Posts: 6,364
Garage
Well the reason I wait is that the instructions said to wait. 2 leds come on with key on then one goes off and when the needle hits 18? I think it is, the second goes off and its ready to start. I think the one led is a self test function and the second is the base calibration which stops at 18 on the needle when the light goes out. This may be something specific to the analog. I don't see these led's on the digital gauge but then it has a display.


Looksa just like deez juan;




65 2+2, 331, C4 presently apart for complete a restore
1979 Ford F150 custom, 302, C4, AC, tilt wheel, main transportation
macstang is online now  
post #9 of 10 (permalink) Old 03-27-2019, 12:53 PM
Senior Member
 
66Ccode's Avatar
 
Join Date: Aug 2018
Location: NJ
Posts: 329
it looks to me like he is just testing the unit he just installed to make sure it was wired correctly. Never seen one that you need to let it warm up every time you want to drive it.
66Ccode is offline  
post #10 of 10 (permalink) Old 03-27-2019, 02:23 PM
Just some guy
Supporting Member
 
GypsyR's Avatar
 
Join Date: Jun 2001
Location: SC foothills, USA
Posts: 18,678
Garage
Odd about the instructions. Again, there's no real info to be gained at LEAST until the engine is warmed up enough to be off the choke. And I know better than to not tweak idle mixtures until a vehicle has been a couple of miles warmed up. Not fooling with adjustments until warm is in like every manual and carb tuning book ever.

OEM's have very tightly controlled warmup cycles because the EPA is on them about excessive pollution during those times. The sooner they can get and engine into closed loop, the sooner they can clamp down on the very last microgram of pollution. Some vehicles like a Prius even keep coolant pre-warmed to shorten the warmup period even more. Which also supposedly gains them a temporary extra 0.5 MPG or something. We aren't held to any such strictures (or freakin care) on our old cars and generally just want to make sure the engine isn't flooding or starving for fuel during the warmup cycle and you sure don't need a wideband to figure that out.
66Ccode likes this.
GypsyR is online now  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Vintage Mustang Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



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

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are Off

 
For the best viewing experience please update your browser to Google Chrome