Cadillac Owners Forum banner

1 - 14 of 14 Posts

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #1
There was recently a discussion on the Rear Wheel Drive forum, about the two fuel economy indicator lights used on '80 RWD's. It is the system that has two small lights in the telltale; one green that is light under normal engine load, and one amber that lights under heavy acceleration (using manifold vacuum as the gauge). They used the same telltale throughout the '80's, so my '89 Brougham has the slots for these indicator lights, but nothing to turn them on.

As it turns out, this system was standard equipment for the '76-'79 Seville (gasoline only), and I found a '77 in a junkyard. The car was pretty trashed, and I was only able to find one thing that was had vacuum ports and an electrical connector:




(sorry for bad pictures)

It was mounted on the manifold, next to the TPS connector. There is a part number; 0837 or 0337 (can't really tell what the first number is).

If there is anyone familiar with the first generation Seville, is this part apart of the system I'm talking about? If it isn't, can I get some part numbers or pictures of what exactly I need to wire this into my Brougham?
 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #2
Some additional information:

There was one vacuum line hooked up from a manifold port to the silver port on the part, and one of the rear ports was attached to something that looked like an EGR valve, but wasn't because it was mounted behind the EGR. The other port was disconnected.

Also there was a two wire electrical connector. One of the wires was brown and went into the harness running toward the firewall, the other wire was black and was routed into the harness going the opposite way.

And I got better pictures:


 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #4
^Because that would defeat the purpose of this project.

This is a description of the system out an owner's manual for a '79 de Ville




As stated before, they used the same instrument panel (tell-tale) on the '89 RWD's, as they did the on the cars in 1980, which had this system as standard equipment. So my car has the amber and green indicators. I'm just trying to install this fuel monitoring system, which was also standard on the first gen Seville.

Any information about how this system worked and/or the parts I need is welcome.
 

·
Registered
2006 XJ, 2000 Eldorado ESC--total loss :(
Joined
·
1,180 Posts
I think what you need to find is a wiring diagram, which will show you what connections those lamps had.

My guess: it should be a very basic single-pole double-throw switch. You have 2 lamps, say one wire of each goes to ground. Then with that switch, one terminal has 12v from a fuse, and the other 2 terminals go to each one of the lamps. When manifold vacuum is high, the green is on. When the vac gets to a certain "uneconomical" level the switch moves and the 12v goes to the amber lamp.

You should be able to easily figure it out which terminal is which using an ohmmeter and a hand vacuum pump.
 

·
Registered
Joined
·
138 Posts
hi

the switch ensures ground due to the mounting screw

both lamps in the telltale have +12V by the telltale and the 2-wire connector to this vacuum switch grounds lamp1 or lamp2.. ground is supplied due to the mounting screw (housing of the switch)

i've the same problem now, to find out how to get the right vacuum^^

best wishes from austria

adrian
 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #7
hi

the switch ensures ground due to the mounting screw

both lamps in the telltale have +12V by the telltale and the 2-wire connector to this vacuum switch grounds lamp1 or lamp2.. ground is supplied due to the mounting screw (housing of the switch)

i've the same problem now, to find out how to get the right vacuum^^

best wishes from austria

adrian
This is the right vacuum switch?

So then I need to figure out which pins on the printed circuit control the monitor lamps, right? Then I need to direct both wires to the tell-tale, right?

I have three vacuum ports on this switch. I know the front (metal) one needs to be supplied with manifold. What do the other two need and/or can one be capped off?

Also, my tell-tale doesn't have the bulbs for the monitor (after 9 years it would be a little asinine), so do you know what size I need?
 

·
Registered
Joined
·
138 Posts
This is the right vacuum switch?

So then I need to figure out which pins on the printed circuit control the monitor lamps, right? Then I need to direct both wires to the tell-tale, right?

I have three vacuum ports on this switch. I know the front (metal) one needs to be supplied with manifold. What do the other two need and/or can one be capped off?

Also, my tell-tale doesn't have the bulbs for the monitor (after 9 years it would be a little asinine), so do you know what size I need?
hi

my switch only has 1 vacuum port and 2 electrical ports for the 2 ground straps of the bulps..

i took the bulps out of a dodge spirit chrysler saratoga, chrysler lebaron, plymouth acclaim instrument cluster... they fit perfectly

then take 2 cables to underhood and take them to ground and the bulps should light..

with ignition on the vacuum switch should let the amber bulb light
and with running engine without throttle the green one ....

but however my switch has only 1 vacuum port
its this one
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=130405288241&viewitem=&sspagename=STRK:MEWNX:IT

but i dont know where to plug the vacuum line in on my v864 368 engine... it should be somewhere on the intake manifold.. i've to try this out....

ciao ;)
 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #9
^Thank you very much. I did not see anything like that in the Seville, but I can go back and check again.

But after thinking about it, I've come up with an alternative, just in case I can't find that part. I can use the MAP sensor to turn on the green light (I just need a bulb that will light at 2.5 volts; an LED probably), and I can rig a low voltage warning circuit to the amber light to make that come on then the green light goes out.

Again, thank you.

-SVEN-
 

·
Registered
Joined
·
138 Posts
^Thank you very much. I did not see anything like that in the Seville, but I can go back and check again.

But after thinking about it, I've come up with an alternative, just in case I can't find that part. I can use the MAP sensor to turn on the green light (I just need a bulb that will light at 2.5 volts; an LED probably), and I can rig a low voltage warning circuit to the amber light to make that come on then the green light goes out.

Again, thank you.

-SVEN-

hi again

u have to think about:
the bulps get + 12 V in the telltale and only ground cables go underhood...

so u must custom the contact plate at the telltale to get there 2.5 volts (or LED with resistor for + 12 V)

what exactly does the MAP sensor?

thanks
 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #11
I found the vacuum switch; it was on the firewall, behind the master cylinder.

But to answer your question... The Manifold Absolute Pressure (MAP) sensor senses engine vacuum and sends a 2.5 volt -5 volt signal to the car's computer, based on manifold vacuum. I was going the run a lead from the signal wire on the MAP to a bulb that was completely isolated from the tell-tale printed circuit. When vacuum is low, the signal voltage is low, so the bulb would go out. To turn on the amber light, I was going to splice a separate wire into the signal wire and wire in a voltage detector, some resistors, and an LED. The whole circuit would not be connected to the tell-tale or the circuitry in it; the lights would just shine through the holes.

But now I don't have to do that. Now that I have the switch and know where ground and power are coming from (thanks to you) I'll have no problem making this work.

Than you for your help.

-SVEN-
 

·
Registered
Joined
·
138 Posts
I found the vacuum switch; it was on the firewall, behind the master cylinder.

But to answer your question... The Manifold Absolute Pressure (MAP) sensor senses engine vacuum and sends a 2.5 volt -5 volt signal to the car's computer, based on manifold vacuum. I was going the run a lead from the signal wire on the MAP to a bulb that was completely isolated from the tell-tale printed circuit. When vacuum is low, the signal voltage is low, so the bulb would go out. To turn on the amber light, I was going to splice a separate wire into the signal wire and wire in a voltage detector, some resistors, and an LED. The whole circuit would not be connected to the tell-tale or the circuitry in it; the lights would just shine through the holes.

But now I don't have to do that. Now that I have the switch and know where ground and power are coming from (thanks to you) I'll have no problem making this work.

Than you for your help.

-SVEN-


hi

sounds great :)

can you explain what vacuum line do you take on your engine... maybe it helps to find a correct one on my v864 368 engine...

thanks :)
 

·
Registered
1989 Brougham d'Elegance, 1985 Fleetwood Brougham *Coupe*
Joined
·
4,256 Posts
Discussion Starter #13
It should work with any manifold vacuum source. I'm just going to find a hose and "T" another line into it, for the switch. It should be connected to line for a device that gets constant vacuum and isn't turned on and off.
 

·
Registered
Joined
·
138 Posts
It should work with any manifold vacuum source. I'm just going to find a hose and "T" another line into it, for the switch. It should be connected to line for a device that gets constant vacuum and isn't turned on and off.
hi

thanks, i thaught same way, so i've try out what vacuum source works :)

ciao for now and a beautiful morning from austria (we have about 8 o clock^^)
 
1 - 14 of 14 Posts
Top