This is something I’ve been meaning to ask about for quite some time, but after replacing my turn signal switch and finding that the PO disabled the key warning buzzer I think now is as good a time as any to go over them…
*Edited:
Here are the various warning buzzers and warning indicator lights that should be operational for a 1970 Cougar Eliminator.
Dash warning lights:
FUEL - low fuel indicator light - on when fuel is low and thermistor is uncovered (“prove out” during ignition with the key in the Start position).
PARK - parking brake reminder light - on when parking brake is set and ignition switch in Run (no seperate “prove out”).
BELTS - seat belt reminder light - on when ignition switch in Run, and stays lit for a few seconds (no seperate “prove out”).
LIGHTS - headlight “on” warning light - turns on when driver’s door is open and headlight switch is not in OFF (no “prove out” for bulb)
DOOR - door ajar warning light - turns on when either door is openned.
BRAKES - brake proportioning valve warning light - turns on when the brake proportioning valve shifts due to loss of brake pressure in either the front or rear brake systems (“prove out” during ignition with the key in the Start position).
Warning Buzzer (one single buzzer relay is shared by both warning circuits)
Key warning buzzer - sounds when key is in the ignition and driver’s door is open.
Headlight “on” warning buzzer - sounds when headlight switch is not OFF, and driver’s door opens
These are good questions Mike. For the belts light, when I put the key in the ignition the “Belts” light turns on in the dash for a few seconds then turns off. Not sure if that’s the correct way its suppose to function but that’s how it works on my Cougar. I believe in order for your Cougar to have the “Belts” light warning in the dash, your Cougar needed to be ordered with the Deluxe seat belts as it was packaged together in your wiring harness with that option.
On my 70 Standard Cougar the option from the Marti report was called “Deluxe Belts/Warning Light”.
Ok, I have heard that before. But looking deeper into the '70 Electrical diagrams, it looks like a “Seat Belt Warning Lamp” is included on all '70 Cougars, BUT the wiring for them is different depending on the model / body - Standard are wired one way, XR-7 are wired another way.
I did see the Deluxe belts in the diagram, but it seems to imply that part of the circuit is for mustang only.
So maybe it is the case that all '70 Cougars got the Belts warning light, but only '70 Mustangs with the Deluxe Belt option got the warning lights?
I could see how that could lead to the belief that only certain Cougars got the Belts light as well.
From the diagram it also appears that all '70 Cougars would have the “Seat Belt Warning Switch” - which I think its only job was to turn on the light for a certain amount of time. The diagram makes it look like a thermo switch.
That matches up with your description as well.
Same sort of setup for the “Parking Brake Warning Lamp”. It appears both standard and XR-7 got one, but they are wired slightly differently.
Which makes sense to me, that all models would have indicators for belts and parking brake.
Now I need to go out and fiddle with my key and see if my Belts warning lights up at all!
*Ok, went out and when I turn the key to Run my “Belts” light comes on for 5-10seconds then goes out (as expected). The “Park” light also comes on (since the brake is set), as well as my “Door” light (since I had the door open at the time). Those are the only 3 lights I get just by turning the key to run.
There where I am too… I believe it is, but I’m not sure :-/
I’ll dig into the schematics some more soon and see what I can figure out from that. Been busy lately.
According to the owners manual, the prove out circuit should light oil pressure light, alt warning, low fuel, brakes, seat belts (as part of the deluxe seat belt option). Lights light and buzzer will come on with headlamp switch on and drivers is opened, park light on whenever E brake applied.
Uh oh… guess I should have read the owner’s manual!
Thanks for the head’s up! Luckily I don’t have to worry about the ALT or OIL lights, as I have gauges (or meters, if you prefer).
My BELTS light functions fine, even though my car does not have the deluxe seat belt option. The electrical diagrams appear to show the Seat Belt Relay as standard equipment (called out as Seat Belt Warning Relay for the XR-7 and wired slightly differently).
My PARK light works fine as well.
The BRAKES light (Dual Brake Warning) is triggered by the proportioning valve, and I know mine functions / lights correctly from fiddling with it previously (yay?).
So that leaves FUEL, which knowing it is on the prove out will make it easier to test (I think). Hopefully it is just a burned out bulb (fat chance, I know). I recall reading somewhere how to test the meter and the light by grounding connections from the fuel sender. I’ll have to dig around and find that info again.
And LIGHTS…
That is what I figured, and also what the schematic appears to show. I’ve never seen my “LIGHT” light …light. Or heard a buzzer with it ~ and I’m pretty darn sure I’ve forgotten to turn off my headlights before, LOL!
Ok, so two more circuits to troubleshoot: FUEL and LIGHT
I guess once I finish fiddling I’ll update my original post with corrections, for future reference.
Ok, did some circuit analysis today and figured out how the FUEL light works. I know, you guys probably already know this, but I’m happy I was able to figure it out from the schematics (I’m pretty sure I got it figgered it out).
Low Fuel Warning Light
FUEL light turns on when key is turned to START (It won’t turn on in RUN unless there is an actual low fuel condition).
FUEL light also turns on when fuel is low and thermistor is uncovered (requires key in RUN as well).
The Low Fuel Relay normally has no power across the contacts. When the key is turned to START it puts power across the relay contacts and lights the FUEL light. When the key is released to RUN, the power to the light is removed. Power to the light during “START” comes from the connection at the Starter Solenoid.
When the low fuel thermistor becomes uncovered, it causes the Low Fuel Relay to switch, applying power to the FUEL light, turning it on.
The thermistor and low fuel relay are also protected by a 20A fuse located in the fuse panel.
So, when troubleshooting the low fuel warning light:
Check 20A fuse in fuse panel.
Check Low Fuel Relay (driver’s side under dash, near emergency flasher relay).
An interesting thing to note about the low fuel relay fuse and FUEL light prove out… During starting the FUEL light gets powered from the starting solenoid connection, but during a low fuel condition the FUEL light is powered via the 20A fuse in the fuse panel.
So if the fuse is blown you would still get the FUEL light lit during starting, but it would not come on during a low fuel condition.
I’m in the process of putting in a new harness in my 70 XR7, reading the schematics it seems the “lights on” warning circuit uses the relay to the right of the radio (10c838 relay assmbly). So when lights are on and door opens power is sent to the relay, the relay closes to send power to two circuits (lights on bulb) and (buzzer 13150 assmbly). The buzzer is on the same bracket as the relay (right of radio). The car only has one buzzer that works for both lights and key from what I can tell.
I think this is right, if anyone knows different please let us know.
I’m also trying to get the seat back release circuit working again, its a bit tricky.
That’s pretty much what I’ve come to learn over the last few days as well. I also had the joy of discovering that for my Eliminator the LIGHTs relay is not in the same location as the XR-7, even though it uses the XR-7 version of the relay (D0WB-10C838-A). From the electrical diagrams, it also does not appear that the Standard (hardtop) version of the relay (D0AB-10C838-A) would mount in the same location - but I can’t be sure.
It appears to me that the difference between the two versions of the relay have to do with the metal mounting tab attached to the relay, and not the relay itself.
Standard (hardtop) version of the relay (D0AB-10C838-A)
XR-7 version of the relay (D0WB-10C838-A)
Mounting location called out in the XR-7 electrical diagram (relay is not shown on the Standard diagram).
Here is what I discovered was the actual mounting location for my Eliminator! Nothing like having to pull the radio to remove the screws for the relay! Yay!
Here you can get a good idea of the position of the Buzzer relay as well as the Light relay.
I found that you can completely remove the Buzzer / Light relay bracket and pull it out with the relay(s) still attached.
The bracket mounting screw is under the dash next to the radio / ashtray.
If your Key Buzzer and / or Light Warning are not working, a few things you should check…
Buzzer Relay - it is a very simple relay with a coil that “self toggles”, causing the relay to open and close rapidly, which makes the buzzing sound. I found that the solder joints on my coil were bad. Continuity of the coil itself was good at the wire ends (about 60 ohms), but not good at the “bus” connection inside the relay. So I added some solder to the connections at each end of the coil (just flowed it right down over wire wraps at each end), and Viola! the buzzer buzzes once again!
L.H. Door Jamb Switch (i.e. driver’s door switch) - the connections to / from / in my door switch are “flakey”. When I joggle the plunger in out and around I get intermittant buzzes when testing both my Lights and Key warning circuits. If the connection / switch was completely bad, I would possibly still be troubleshooting other components! Replacement switches are available from your favorite Cougar vendors, but be sure to get the right one! '70 driver’s door requires 3 pin connections, as you see in the diagram.
Here is the schematic for the Light Warning and Key Buzzer circuit, with some notes.
Notice that the Light Warning relay has a seperate line for the Buzzer and the LIGHT in the dash. So it appears that if the relay has a partial failure, it is possible to get a Buzzer but no dash LIGHT - that is my current situation, which I am still trouble shooting. Unfortunately, it appears that the dash LIGHT indicator is not included in any sort of prove out circuit - as far as I can tell. So I don’t know if my problem is a burned out bulb, or a bad relay. And based on the position of the relay (see previous post), either one will be difficult to check.
Here is a highlighted drawing that I found for the Seat Back Release circuit. I didn’t even see that circuit called out in any Cougar-specific diagrams, but it should be very similar.
So the current status of my adventures with indicators is that I’ve fixed the buzzer. The Key warning and Lights warning buzz now works, with the exception of a flakey door switch (I get just a quick “bzz” when openning the door).
My LIGHT indicator in the dash is still not functioning though. I’ll need to either pull the dash and check the bulb, or pull the radio and check the relay. Or both :-/
