I have a 70 SS and was wondering if anyone new the color codes for the oil/temp lights? and also are they single or double leads and is there power going to these leads. thanks steelworker

Oil light is dark blue while temp is dark green. You will see 12 volts, on these leads, with the key on, sender leads disconnected, and the bulbs installed.

at the cluster there are two leads going to dummy light
pink will be the hot side dbl is oil and dg is temp
johns test is correct for under the hood
sometimes if 12 volts are not present the idiot light bulbs may be bad

tom is the water temp a double lead wire or single like the oil pressure? with key on if there is 12 volts going to it wont it pop fuse if i ground to frame like you said? thanks steel

the temp light is a single green wire

oh and no it wont pop the fuse it will turn on the light
what you see is the same as an open swich
the voltage can be read across the switch until it is closed

tom, if the water temp lead is single then i cannot find, my schematic shows a double wire,comes in and then comes out thew other side and goes to what itlooks like a nother terminal from temp switch into a terminal out looks like a black/dark blue one going to tcs switch the other going totrans switch,this is driving me nuts. By the way i did find the oil light single lead grounded like you said light came on. Thanks steel

the dark green wire goes from the idiot light to the ignition switch then to bulk head then should be in the same part of harness as the wires that go to lights and regulator
if it is a six cylinder the wire will be in the alt part of harness
if it is an eight then the wire comes out of the harness about one foot from bulk head and normally has protective fabric wrapped around it
and will be on drivers side 6 will be on passenger side

The oil and temperature warning light circuits are very simple. Your engine is "ground". You'll have a positive voltage going to the light when you turn on the key.

The ground side of the light goes to the sensor. The sensor is nothing but a switch. When the switch closes (low oil pressure, or high temperature), it completes the circuit to ground.

So you have a constant hot going to the light, and a ground going to the sensor. But there is no ground until there's a problem. That's when the light comes on.

I set mine up with LED's.

there is a light green wire but that goes to the headlights
you are definately looking for a dark green wire
lg is 16 gauge
dg is 20 gauge (thinner)

there is 2 connectors in the bulk head, am i going to be looking in the one closest to the fender or towards the center of car? the one for the oil is in bulk head connector towards the center of car. thanks steel

PS 402 BB engine. steel

oil is in one farthest from fender
temp is in one that is closest, should be either 2nd or 3rd row down and 2nd column in from fender

thank you my friend i will check in a bit. i'll send reply in about 2 hrs. thanks steel

i dont know for sure but the temp sensor may have an extra wire in the system to stop the cowl from opening before coming up to temp
this is just a wild --- guess though
i've seen this application on other vehicles for different reasons
but i have no schematics on a 70 with these options

hey tom, cannot find a single green wire coming out of the one closest to fender except the one going to the lights. there is two coming out of the inboard harness hub one green and one green with a white stripe. both of these wires are going to a common plug, this is the plug i was asking you about b4, the harness in this car is from a 1972, but the car is a 1970 chevelle,i have both of the schematics (70/72) and neither one shows green with white stripe. turned key on powered up nopower in either wire, unlike the oil pressure. someone helpppp graemlins/clonk.gif steel

tom if your there reply back i got a couple more questions. steel

I checked all over and can't find anything
the only way I can Think of is to go right from the temp light and make sure it is green there
then go to fuse box and find the same wire
(you may need to unbolt it from the firewall and split it open (3\8" head for bolt in center of bulkhead under hood and 5/16" head on inside then two plastic retainers)and see where the wire goes to then follow it through the bulkhead)UNHOOK THE BATTERY
I will check back around 1 pm eastern

graemlins/angry.gif going nuts here

Under the dash the green temp wire can be found on the ignition switch.

hEY jOHN, SO THERE IS 2 WIRES ,i THOUGHT SO, MY QUESTION IS SHOULD THERE BE POWER COMING OUT OF THE ONE WIRE? THERE ISNT THATS WHY I'M ASKING, OR DOES IT HAVE TO RUN THROUGH THE TCS SWITCH TO COMPLETE A CIRCUIT? THANKS STEEL

No power as Steve mentioned. Only one green wire goes back to the bulkhead connector. Wouldn't worry over the other wire on the connector. It's another "switch" inside the sender and has nothing to do with the idiot light. It's TCS stuff and willing to bet your TCS system isn't working. They weren't very good and died years ago.

JOHN, HOW THE HECK AND HOW THE HECK DOES IT GET POWER IF IT ISNT HOT ALL THE TIME??? HATE TO PUT THIS DASH BACK TOGETHER WHEN I GET MY ENGINE BACK AND IN AND FIND OUT IT DOSENT WORK, CAN YOU EXPLAIN HOW IT WORKS. THANKS STEEL graemlins/beers.gif

I think if you touched this to ground and had no light
and also don't have 12v when not connected
check to see if bulb is ok (if it is blown you won't have 12v and it definatly won't light)

tom read other posting.

Originally posted by steelworker198:
JOHN, HOW THE HECK AND HOW THE HECK DOES IT GET POWER IF IT ISNT HOT ALL THE TIME??? HATE TO PUT THIS DASH BACK TOGETHER WHEN I GET MY ENGINE BACK AND IN AND FIND OUT IT DOSENT WORK, CAN YOU EXPLAIN HOW IT WORKS. THANKS STEEL graemlins/beers.gif Is there a problem with the cap lock key? All caps is considered shouting at another.

graemlins/hurray.gif graemlins/waving.gif graemlins/thumbsup.gif
thanks to all. steel

For 70 you should have two temp sensors, one for TCS (passenger side head) and one for temp light (drivers side head). The TCS switch will have 2 wires, this is a wired OR circuit, one terminal is for low temp and the other is high temp. When the temp is below 82 deg OR above 232 deg you get a ground and this activates the Override relay which overrides the TCS. The temp sensor you want is in the drivers side head. I don't have any cowl induction wiring so I can't say if it should have one or two wires on it.

Steel,

I don't want to throw a wrench into your previous information which is all good BUT.....It may help you to go to a website called "the 73 spot" It has a schematic of your TCS/cowl switch setup. The wiring diagram helped explain many things on my 70 Ls6 that were messed up. Obviously it's for a 73 vette but "any port in the storm"

Your Oil pressure should be 20g dark blue, your temp is 20g dark green.
Now to screw with you some more the TCS uses a 20g Drkbl, 20g pink & 20g drk green.

If you don't have one already I can fax you a schematic or you can just buy one off the net. It's easier to look at pictures of the bulk head connector and follow the wires that way.
This is of course all depending you have the 70 engine/front end harness.

Think Steel has it going. There's no pink wire on the 72 TCS system, only greens coming off the sender. Get's a little confusing with the mix and match wiring stuff. I for one am glad this area is so well supported with people who try to help. I don't know many answers and need all the help I can get.

Hi John-
Pardon me a second. I'm glad you and others are so helpful too!!!! Bodywork is one thing....wrenching on an engine is another......but electricity is....MAGIC!!!

Gonna post a topic......"MSD,TCS, and Other Four Letter Words" soon.......

Might need your assistance.......can I put you on a retainer......hehehe..

Back to the Chevelle topic.......
ktownkid

Originally posted by ktownkid:
Hi John-
Might need your assistance.......can I put you on a retainer......hehehe..
ktownkid Always ...if you wander over and figure out why my 64 trunk lid doesn't fit right. Hate body work.