'69 Chevy C10 250 in line 6. I connected my existing original oil pressure sensor to my Autometer pressure guage. I get nothing. Before I order a new sensor, is there a way to test both the electric oil sensor and my Autometer gauge individually to see which is bad?
2nd part of question...the oil pressure sensors for electric vary in price from $8 to $37 and dozens of types/shapes/styles. My gauge has it's own light. Why would I want to spend more? I'm old enough (78) and experienced enough to know price does not necessarily indicate quality. I would like a sensor that is actually for my truck, yet those choices are also abundant and vary substantially in price.
What is the model number of your Autometer pressure gauge? Is your original pressure sensor a pressure switch (fault light) or pressure sender (pressure gauge) or both.
Oil pressure gauge types:
Mechanical with [/s]filled gas tube[s] oil filled tube. Electrical switch (on/off) Electrical pressure (analog) Electrical digital (digital communication with the gauge) Electrical digital computer bus (digital but shares a bus system to talk to a central computer)
We have to figure out what you have before we can try to recommend what you need.
Last edited by buoymaker; 07/09/202211:10 PM.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
To answer the 2nd part of your question, usually the sending unit works on resistance and you can check to see if it is operating with a common handheld meter (using the ohm setting). More or less oil pressure will cause the gauge to receive different resistance values. But there are a couple of different kinds. Some also output different voltage amounts. More or less oil pressure will cause higher or lower voltage values. As mentioned above, we really need to know which gauge you have. Note: some of the AutoMeter sending units can be pretty costly.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
What is the model number of your Autometer pressure gauge? Is your original pressure sensor a pressure switch (fault light) or pressure sender (pressure gauge) or both.
Oil pressure gauge types:
Mechanical with [/s]filled gas tube[s] oil filled tube. Electrical switch (on/off) Electrical pressure (analog) Electrical digital (digital communication with the gauge) Electrical digital computer bus (digital but shares a bus system to talk to a central computer)
We have to figure out what you have before we can try to recommend what you need.
I've looked over the Autometer with a magnifying glass and the only mark are the white letters [4 80 or 89, can't tell], and am attaching pictures of both the sensor and the gauge. Would this be considered an electric air core gauge?
Hmmm, well that's a short sweep 0 to 80 gauge. I don't believe they make that one any longer, but a sender might be available. You should contact AutoMeter. Short sweep and full sweep gauges used different senders. The sender in your engine may not mate with that gauge.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Hmmm, well that's a short sweep 0 to 80 gauge. I don't believe they make that one any longer, but a sender might be available. You should contact AutoMeter. Short sweep and full sweep gauges used different senders. The sender in your engine may not mate with that gauge.
You're right, I looked at 211 oil pressure gauges of Autometer, at least I think it must be an electric air core gauge, short sweep. But the recommended senders for the '69 C10 look exactly like my picture. Any way to test these senders off the engine or the gauge?
You could test the sender off of the engine, but you'd have to be able to subject it to oil pressure somehow. There's no way to test the gauge...same problem. Please note: the OEM sender for the 69 C-10 probably won't work with the gauge you have. That's why I said you need to contact AutoMeter and find out what they suggest.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
You could test the sender off of the engine, but you'd have to be able to subject it to oil pressure somehow.
If you have an ohmmeter and a source of variable air pressure that you can plumb the sender into you can at least tell if it is a switch for an idiot light or a variable resistor for a gauge.
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
If it is only an idiot light device, it will be a closed circuit when there is no pressure against it. That's why it lights up nice and bright when you turn the ignition to "on". Once it receives pressure of 7 or 10 pounds, the switch will start flickering on/off (making the idiot light flicker also) and then when pressure exceeds about 12 to 15 pounds, the circuit will be completely open and the idiot light will be off. If you just check between the wire tab and ground with the engine and ignition off, you can tell. If the wire tab when connected to ground is a closed circuit, you have an idiot light device.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Excellent, I understand now the difference in senders. I would bet 10-1 odds that's an idiot light sw and that's why my gauge didn't respond. Thanks Bill and Jon.
Your gauge is listening in French, and the sender is speaking Russian. The "sender" in the picture is probably a switcch that only serves to turn an idiot light on and off. If you want the gauge to work, you'll need a variable resistance sender that is compatible with the calibration of the gauge. I don't know of a sender offhand that combines light and gauge functions into one unit. What sender does Autometer reccomend for that gauge? Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
Tonerman, let's go back over this again. Originally did your truck have an oil pressure light or an oil pressure gauge?
Please correct me if I wrong but on the Autometer gauge I see:
White wire = dash lights? Green wire = ground? Black wire = signal? Did you pull this wire off of a oil pressure lamp or oil pressure gauge? The other end of the wire would be going to the block. Red wire = +12 volts?
Did you do this wiring yourself?
The reason I ask is that if you originally had a light before, then you need a "Tee" connection at the engine block. This will give you one connection for the existing oil pressure switch and a connection for an oil pressure sensor that you need to purchase. You then can wire it so that you have both the light and gauge working. This is the best way to do it.
Last edited by buoymaker; 07/11/20222:46 AM.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
Your gauge is listening in French, and the sender is speaking Russian. The "sender" in the picture is probably a switcch that only serves to turn an idiot light on and off. If you want the gauge to work, you'll need a variable resistance sender that is compatible with the calibration of the gauge. I don't know of a sender offhand that combines light and gauge functions into one unit. What sender does Autometer reccomend for that gauge? Jerry
Autometer replied that the 2241 sensor would work. Lowest price is $33 on Ebay (most of this 2241 sell in the $50 range). 1aauto.com said their sensor ESSOO550 will work with my Autometer. Their price is $28. Both include shipping. Think I'll try 1aauto sensor.
Tonerman, let's go back over this again. Originally did your truck have an oil pressure light or an oil pressure gauge?
Please correct me if I wrong but on the Autometer gauge I see:
White wire = dash lights? Green wire = ground? Black wire = signal? Did you pull this wire off of a oil pressure lamp or oil pressure gauge? The other end of the wire would be going to the block. Red wire = +12 volts?
Did you do this wiring yourself?
The reason I ask is that if you originally had a light before, then you need a "Tee" connection at the engine block. This will give you one connection for the existing oil pressure switch and a connection for an oil pressure sensor that you need to purchase. You then can wire it so that you have both the light and gauge working. This is the best way to do it.
Yep, it was an idiot light, but I'm not going to use that. Going to get the recommended sensor ESSOO550 from 1aauto.com. I appreciate all the help here and now am almost an expert on oil sensors. Next I have to work out the connection to an Autometer electric gauge for the water temp. Should be a lot easier now.
A red oil pressure lamp gets your attention. You then look at the oil pressure gauge. If no or low pressure, both hopefully give you time to shut the engine down before major damage happens.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
The dirt track race car we ran in California had an idiot light- - - -actually an oval red clearance light for an 18 wheeler- - - -mounted right in the driver's line of sight as he looked over the hood. A 3" diameter oil pressure gauge was mounted on one side of it, and the same size temp gauge was to the left. The light was wired to a pressure switch that turned it on at 20 PSI or below. In a hard left turn the light would flicker, but if it came on steady the driver could glance at the gauge to see what was going on. As the engine builder, I'd rather lose a race occasionally than hand grenade a $12K engine because the driver didn't look at the gauges often enough. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
I do kind of agree with you on having both, now that you mentioned it. Couldn't hurt. I've mostly had gauges and in 60 years of driving have learned to depend on them. The one occasion (and it was with this truck) when I only had an idiot light...it didn't come on. I had very low oil pressure and only noticed the problem with the change in engine sound. Luckily caught it in time and shut the engine off. It was close, but that was a few years ago and engine still behaves great.
Got myself an Autometer electric oil sensor to match my Autometer gauge, and now just have to drain the oil and install. Going to get oil today, and then test it installed.
Why "drain the oil"? Is the truck due for an oil change?
'57 GMC 102, Original 347 V8, HydraMatic, 3.08 rear gear, added A/C, disk front brakes, HEI, AFB carb, '98 Honda Black Currant paint. T-boned and totaled 10/12 '52 GMC 152 Stake Bed, Original 228, SM420, added A/C, HEI, disk front brakes, '67 Chev 3.55 rear gear. Gets used as a real truck.
