Gauge cluster F%#k!

[HotRodPC]

I'd say it's oil pressure, since these motors don't have an oil level indicator. And yes it should be on with key on and the light having power the swtich beeing grounded being that without the motor running and NO oil pressure to take the switch off of ground that completes the circuit for the light. So I'd say your Oil Light IS NOT Operational. How did you do your pinout? Did you convert your Oil SWITCH wire to an a Gauge SENDER wire? So now where does the Oil SWITCH get it's ground from? If that is all correct, then the light is burned out, or there is no power to the light.

Idiot lights should have power as soon as the key is turned to ON. Then anytime a switch is reading a bad signal, it's sends the ground to complete the circuit and turn the light on.

 

[89Suburban]

Now that I have gauges in this truck I have a question. This 1975 cluster only has two warning lights. The speedo has a BRAKE indicator light and the tach has one marked OIL. I guess that the OIL light is supposed to indicate when the oil in the truck is low, but it could also be oil pressure since the old cluster had idiot lights and it may be working off that wire from those lights. Since the new cluster has an oil pressure gauge I need to know what the OIL light is for. Was it originally acting as a low oil warning, or low pressure warning in its original vehicle? Also, when I turn the truck on, the BRAKE light illuminates, but the OIL one does not. I thought both should illuminate to show that they are operational...?

I have never heard of a low oil (level) warning light or sensor on these trucks. Just a pressure light.

 

[FRANKENTRUCK]

I installed all new bulbs on every light socket before this cluster was installed. I even replaced the oil light socket a few minutes ago to test, but it still does not illuminate when I start the truck like the BRAKE light does. If memory serves I believe the oil pressure wire was spliced into this OIL light sending wire in the 1975 cluster. I seem to remember two seperate ground wires in the diagram. I have to consult the diagram that Robert assisted me with.

 

[HotRodPC]

And I"m not so certain the brake light is supposed to come on with the key either. So that makes me think, you might have a pinout crossed, and the brake light is actually an oil light. Are you sure your brake light switch on the E brake pedal is correct? IF so, put the E brake on and see if you oil light comes on.

 

[RetroC10Sport]

BRAKE light should come on in start I want to say.

 

[FRANKENTRUCK]

The BRAKE light illuminates when I press the Emergency brake pedal.

 

[HotRodPC]

The BRAKE light illuminates when I press the Emergency brake pedal.

OK, just checkin. So we KNOW that is correct.

 

[FRANKENTRUCK]

So I now need to figure out if the OIL light is supposed to illuminate upon starting. And it appears that I now have an oil warning light AND an oil pressure gauge! Not bad! The warning light will have to suffice until I find the oil pressure line and connectors I need.

 

[chengny]

There are 3 major checks that happen while starting the engine (not including the seat belt light/buzzer):

When the key is moved from the OFF to the RUN position, the oil pressure warning (or in many cases the CHOKE light) should iluminate. It is also lit when the key is in the start positon. Only when sufficient engine lube oil pressure is established (about 10 psi) should that light extinguish. And it should stay that way until the engine is stopped - regardless of key position.


The other two are visible checks for functionality and are supposed to be observed while cranking the engine (no one ever does).

While the key is twisted to the start position, the coolant temp gauge (and the brake warning light) are shorted to ground through the ignition switch. The temp should peg out high, the brake light should illuminate.

If everything is wired right, they do actually peg high and light up respectively. Watch sometime.

As opposed to the oil pressure light (which provides both a lamp check and a realtime condition test), these 2 quick visuals only tell you that the instrumentation is functioning - they provide no information about the state of the brake system or the actual temp of the coolant.


The BRAKE light illuminates when I press the Emergency brake pedal.

It should, and it is independent of key position (as long as the key isn't turned to OFF).

The brake hydraulic pressure failure switch uses the same warning light as the "parking brake engaged" indication. Not usually an issue.

 

[robert8096]

So why doesn't this guy Robert post up and participate?

I do but I don't really have the time to do much posting. Plus there are a number of regulars who give good advice and I see no reason to post the same information.

I installed all new bulbs on every light socket before this cluster was installed. I even replaced the oil light socket a few minutes ago to test, but it still does not illuminate when I start the truck like the BRAKE light does. If memory serves I believe the oil pressure wire was spliced into this OIL light sending wire in the 1975 cluster. I seem to remember two seperate ground wires in the diagram. I have to consult the diagram that Robert assisted me with.

I don't remember seeing any of these trucks with both an oil pressure gauge and a functioning oil pressure light but I could be wrong. We will need to look at what pins are connected to that light and go from there. I am positive that for the oil light to work we will need to retain your existing oil pressure switch and find a new location for the mechanical gauge connection. Most of the time there is a port we can use for this located near the oil filter. Give a call and we will try to get together and look at it.

 

[89Suburban]

The other two are visible checks for functionality and are supposed to be observed while cranking the engine (no one ever does).

While the key is twisted to the start position, the coolant temp gauge (and the brake warning light) are shorted to ground through the ignition switch. The temp should peg out high, the brake light should illuminate.

If everything is wired right, they do actually peg high and light up respectively. Watch sometime.

I got to go look at mine now, lol...

 

[HotRodPC]

I do but I don't really have the time to do much posting. Plus there are a number of regulars who give good advice and I see no reason to post the same information.



I don't remember seeing any of these trucks with both an oil pressure gauge and a functioning oil pressure light but I could be wrong. We will need to look at what pins are connected to that light and go from there. I am positive that for the oil light to work we will need to retain your existing oil pressure switch and find a new location for the mechanical gauge connection. Most of the time there is a port we can use for this located near the oil filter. Give a call and we will try to get together and look at it.

I've never seen one that had both either. I just thought maybe it was cuz I didn't pay any attention to that. My truck is going to have both, but NOT OE. I'm getting a Blue and Red Pilot light to be hooked to a switch for 100 degree Cold light goes off and will shut the E choke off in full, and 253 degree Red Light for overheat, and I'm skipping the 210 Caution yellow light, not doing that one this time And I'm doing an oil pressure switch under 10lbs psi will set a dufferent Red Pilot light off.

Me personally, I'd rather have had an Idiot light cluster with those biggo Red Billboard lights and ran a Trio Set of good quality mechanical gauges. Instead I'm going to go ahead and trust the OE Electric gauges backed up with Piliot Idiot lights that I'll run the wire for.

 

[robert8096]

I'm getting a Blue and Red Pilot light to be hooked to a switch for 100 degree Cold light goes off and will shut the E choke off in full, and 253 degree Red Light for overheat, and I'm skipping the 210 Caution yellow light, not doing that one this time And I'm doing an oil pressure switch under 10lbs psi will set a dufferent Red Pilot light off.

I like that idea.

 

[HotRodPC]

What I'd like to get to the bottom of, is why the hell did GM set the Electric CHOKE up based on Oil Pressure? Many get a Choke light on and go nuts trying to figure it out and many times it's a damn Oil Pressure switch has gone defective and then the E Choke don't work. Whooda thought to check a Oil Pressure Switch for a Choke light? Not Me. Kinda like checking tire pressure for an overheating issue. Makes no sense to me.

So I'm going to switch my E choke to my E Choke Eddy carb to the Cold/Hot Switch. What's nice about it, in the winter if you warm you truck for a heater, you can go out and see if the blue light is off and then know you've got at least got 100 degree temp and blowing a bit of warm air before you get in and take off. And when the light goes off that also means the Choke lost power and your choke should be shut off 100% and not dragging or hanging up.

 

[FRANKENTRUCK]

Will someone on here confirm if these below items will work on my 1975 C10 mechanical oil pressure gauge? (that is installed in my 1981 truck) I called the speedway company and they tried to convince me that the "A" and "N" in the serial number means it will only work on military vehicles (i.e. Army Navy). And what about the classic parts copper tubing and attachments? It is listed as being for 1947-1977 trucks but does not show up in the 1973-1987 section which is confusing. If someone on here has used these and they worked please let me know.

http://www.speedwaymotors.com/Straig...ters,6457.html

http://www.speedwaymotors.com/Gauge-Fittings,949.html

http://www.classicparts.com/1947-77-Oil-Pressure-Gauge-Line-Kit/productinfo/24-781/