So my oil light never comes on (I assume it should come on when starting). I figured the bulb was burned out but when I was replacing the radiator I noticed this:
The wire circled in blue leads to a connection at the front of the block. I'm thinking this is for the temperature?
The connector circled in green, is this the oil pressure sensor for the oil light?
Finally, circled in yellow is what I think is the oil pressure sensor. The unplugged connector does not reach however. If that is the wire for the oil light, I'm confused as to why it is shorter than the OPS!
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)
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looks like someone rerouted your wire bundle. On a car this old anything can happen, likely the engine was change or a head gasket and it just was not put back on the correct way.
yes, it looks like that's the OP sender wire. unlike a lot of other sensors, the wire slides on to the sender at a 45* angle. the circular metal part of the sender should slip into the track of the connector. and yes, your oil light should come on when you turn the key to on, and should go out almost immediately after start up.
I tried grounding that wire to test the light, and no light. I guess the light is out too! I'll see if I can figure out how to get the cluster off without breaking anything to replace the bulbs later.
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)
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irowiki wrote:I tried grounding that wire to test the light, and no light. I guess the light is out too! I'll see if I can figure out how to get the cluster off without breaking anything to replace the bulbs later.
being a 1st gen, it will be slightly different but the basic idea will be the same. pics 5-8 of the following link will apply. pay special attention to the part about the speedo cable. it can be a pain if you don't know about it because it's difficult to see but once you know how, it's easy to get off.
I had the screws off at one point but couldn't figure out how to pull it out enough to get my hands back there. I'll try again using your pictures as a reference, thank you!
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)
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if you get the hood off but still can't reach behind the cluster to unclip the speedo, you may have to pull on the cable from lower down on it to get some slack. failing that, sometimes speedos have an intermediate joint where they can be unscrewed from each other. there is usually a plastic bushing that sits between the ends though so make sure not to lose that, or forget which way it sits. once the two parts of the speedo are disconnected you can pull the cluster forward and unclip the speedo from it.
it is pretty rare that the tiny bulb on the idiot lights fail (they do, but it is not common), I would make darn sure it was actually the bulb and not something else before I took it all apart. check the wiring diagram for your car to verify that there is not some other terminal, fuse or something else between the sender wire and the bulb. It is just as likely it is a bad or corroded contact as a bad bulb.
If the wire is not hooked up to the oil pressure switch, would the light be on or off by default? I'm going to hazard a guess (since my wiring diagram is at home) that the oil pressure being normal breaks the circuit, so when there is no pressure, it grounds the wire hence the light turns on.
I grounded the wire and the light didn't turn on, I even tried jumping it to the OPS and no light either. It's really dirty though so I'll give it another try tonight.
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)
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there might also be a fuse between the lead and the light, or several terminals that could be loose or corroded.
Yes, it comes on when grounded. I know that for certain, I have no Oil pressure sender at all in my car (I have a mechanical oil pressure gauge), but somewhere my wiring has chaffed through and my oil pressure light flickers on and off sometimes (very annoying). I assume is is grounding somewhere.
the oil light will not come on if the wire is not grounded, and it will come on if it is.
removing the cluster is not hard, and i have actually seen quite a few burnt out warning lights. since you have grounded the wire and the light has not come on, i would guess that the bulb is the culprit.
I am not sure what year tercel you have but that may be the wrong wire for the oil pressure light. The one for mine comes out of the harness that also goes to the back of the alternator. It attaches to a small pigtail that goes to the switch. Our cars don't have too many accessories but I seem to recall seeing the odd spare wire in that location, so I would check a wiring harness to be sure.
marlinh wrote:I am not sure what year tercel you have but that may be the wrong wire for the oil pressure light. The one for mine comes out of the harness that also goes to the back of the alternator. It attaches to a small pigtail that goes to the switch. Our cars don't have too many accessories but I seem to recall seeing the odd spare wire in that location, so I would check a wiring harness to be sure.
You are amazing, I found an unplugged connector on the back of the alternator, threw a test light on it and the oil light ever so slightly lit up! Jumped it with some wire and it lit up all the way!
I was just about to post that I couldn't get the cluster out too.
Crazy question, what sort of connection is the OPS anyway, can I get something from the auto parts store?
Last edited by irowiki on Wed Jun 05, 2013 10:13 pm, edited 1 time in total.
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)
Site administrator, if something is broken, PM me!
irowiki wrote:Crazy question, what sort of connection is the OPS anyway, can I get something from the auto parts store?
do you mean how does the connector on the wire attach to the sender? if so, my previous post mentions it:
dlb wrote:unlike a lot of other sensors, the wire slides on to the sender at a 45* angle. the circular metal part of the sender should slip into the track of the connector.
