Oil Pressure gauge

[Mr. Stroker]

Hmmm thats a helluva idea! Il be in the city this weekend and il stop at lowes and see what i can find. I definatly like that idea of using the old style setup! Great idea!

But again i still want the pods.

 

[Mr. Stroker]

Mike... Why in the hell would you give me negative rep for post #2? I mean I really could care less about the negative points but it's the principle... I was trying to help you by offering some information that you MAY not have known... How was I supposed to know?

Pretty rude if you ask me...

I have known, its been explained in multiple threads in the past. Yes maby its good info for someone who is new to the forum but SEARCH! To me its a chance to have the thread hijacked by post 3. I want helpful ideas on how to get two gauges to work at once, not information on how it works.

 

[Skandocious]

Mike I was telling you because I thought maybe you didnt know that the stock gauge is virtually useless. You said you wanted to use the two in conjunction and that way I saw it-- since the stock gauge is an idiot light, it's of absolutely no use when you have an aftermarket gauge.

It wasnt off-topic, therefore it couldnt have hijacked the thread...

 

[Mr. Stroker]

I do read the threads chris. And why would i want a mechanical gauge if i didnt know that the factory one is an idiot light?

 

[surewhynot]

Mike, Chris was just merely trying to help. Not all posts will give the answers you want, but when somebody is trying to be helpful, why stress?

Back to the subject guys. Lets play nice.

 

[Skandocious]

I do read the threads chris. And why would i want a mechanical gauge if i didnt know that the factory one is an idiot light?

Because the factory one doesn't have number readings on it... If it were a fully operational gauge it would still be pretty useless without a scale of values.

 

[Mr. Stroker]

Ok so any other ideas on HOW I CAN HAVE TWO OIL PSI GAUGES AT ONCE work?

(big diff on asking how it works eh?)

 

[surewhynot]

I have used a brass t fitting before to put an aftermarket gauge on and keep the stock one.

 

[radialarm]

Ok so any other ideas on HOW I CAN HAVE TWO OIL PSI GAUGES AT ONCE work?

(big diff on asking how it works eh?)

Go to the hardware store and get a tee, and any other fittings you need.

 

[Bob]

Here's something I just tried on my '91 and it worked... sorta.

Cut the fitting off the end of the stock wire and ground it to the block. Dummy gauge reads normal. Remove it from ground, dummy gauge reads low. YMMV.

 

[Mr. Stroker]

Thanks guys. Il have to see what i come up with this weekend.

 

[NeXtras]

hey Skan.. can you show me that diagram of the stock gauge..

how can it be a simple on/off? theres got to be some sensor there measuring the pressure...

 

[NeXtras]

Because the factory one doesn't have number readings on it... If it were a fully operational gauge it would still be pretty useless without a scale of values.

can i argue that? lol.. what about your temp gauge.. no values, just cold and hot.. and thats fully funtional.. but i do want to see that diagram about the pressure.. cause SOMETHING has to detect pressure..

 

[Mr. Stroker]

Only put 2 quarts of oil in your truck on the next oil change and start it up.... See if the gauge sits lower.. LMAO

 

[Skandocious]

hey Skan.. can you show me that diagram of the stock gauge..

how can it be a simple on/off? theres got to be some sensor there measuring the pressure...

You betcha. Direct from my Ford Shop Manual:

Note the difference between the temp "sender" and the pressure "switch". A switch is strictly on/off; if you look at the illustration it shows a swinging arm that either opens or closes the circuit, nothing inbetween. While the temp sender has a variable resistor that will send different values back to the gauge, where they get evaluated and displayed.

If you read the little blurb next to the oil pressure switch it explains it perfectly

 

[Mr. Stroker]

What would the gauge read if it was slightly open or slightly closed?

 

[Skandocious]

It's not possible. The nature of a "switch" is that it's either open or closed. If it's SLIGHTLY open then the circuit is not complete, therefore its the same as being FULLY open.

The contacts in the switch are either touching each other or they aren't-- no deviation from that, you know?

 

[Mr. Stroker]

The light switch in my house goes half way and stops, but no lights. Weird..... Yes i know

 

[Skandocious]

The light switch in my house goes half way and stops, but no lights. Weird..... Yes i know

That's a good analogy Mike.

An ordinary light switch in your house is analogous to the oil pressure switch-- you can push the switch up very slowly and the lights will stay off until the contacts touch and suddenly the lights come on, at full brightness.

Whereas you could have a dimmer switch in your house-- this is more analogous to the temp sender. You're sending a variable signal out from that switch and to the lights, so you can set the lights at an infinite number of brightness settings.

 

[subford]

Skandocious is correct, here is some more information that may help you understand what they did also.

The 20 ohm resister stops the gauge in the middle when the switch is closed.
This is how they used the same type gauge for oil pressure as they used with oil pressure senders in the 80s.

If the 20 ohm resister was not there or jumped and the switch closed it would go to full scale.
If the 20 ohm resister is open, the wire from the switch is open or the switch will not close then the gauge will read low at all times.

This why you can jump the resister and install and old type oil sender and it will read like a real gauge.
See my posts above for more information.