Question about 1986 Cadillac Seville

Open Question

1986 seville engine control system light on. speedometer reads ooooo

Heater control does not work, information center reads system problem

Posted by Anonymous on


6 Suggested Answers

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

  • 66 Answers

SOURCE: none of the information centers on my 92 seville work

You can get plates without mileage - just check box for "in excess of mechanical limits" - there is a box you can check for something like that I believe - sounds like the control module ....Pricey and common failure...Sorry I couldn't help more,,,,

Posted on Aug 30, 2009

  • 655 Answers

SOURCE: I have a 92 Seville and the problem is with the

The backlight bulbs are burnt out. Common on this model. Unfortunately, it is NOT an easy fix. You'll need to pull the dash cluster and replace the bulbs. It involves de-soldering the old bulbs and replacing with new. I have done this but it is very time consuming and you MIGHT damage the circuit board if you are not adept at micro-soldering. IF you do this, replace ALL the bulbs as others will slowly burn out. Replacement bulbs are NOT available thru GM. You'll need to go to a place like MCM Electronics or Top Bulb to get the correct one....There are businesses on-line that specialize in dash repair. GOOGLE to find them.. They ususally charge $100 for this service.

Posted on Nov 22, 2009

  • 1810 Answers

SOURCE: instrument panel reads all zeros on the odometer,

check your fuses then check all your grounds especialy the body grounds

Posted on Mar 18, 2010

  • 1 Answer

SOURCE: cadillac seville won't start

I've got an even cheaper and easier solution, instead of buying a new cylinder, find that plug and snip the orange wires going to the old cylinder.Then remove the resistor chip from the key and solder each of the the wires to each side. this will fool the car into thinking the correct resistor chip is in place, allowing you to use the original key or any copies with or without resistor chips. i just did this to my caddy and it roared to life! :)

Posted on May 20, 2010

  • 3113 Answers

SOURCE: My 1991 Cadillac Seville speedometer sometime

BCM and right lower switch at the info center.

Posted on Jun 06, 2010

Testimonial: "Aloha from Hawaii. My wifes 91 has not reached 100K yet but every once in a while has a senior moment. The strange condition has not happened again but the information was very helpfull. Mahalo and Thank You."

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

2 Answers

Lights or fuse for my speed odemeter guage and heater/air conditioning system

These lights for the dash are controlled by a rheostat instrument control dimmer switch next to the main light switch for the headlights, it is either turned off (have seen this dozens of times) or it is defective. Below is a picture of the switch assembly I speak of. The thumb wheel next to the knob is the dimmer control.


Feb 13, 2012 | 2000 GMC Yukon XL

2 Answers

There is coolant leaking on the passenger side underneath of the car and rear of engine. It doesn't seem to be the lower hose and both the rad and thermostat are new and appear to be dry. I suspect the...

agree, heater core. see procedure below


  1. Disconnect the negative battery cable and disable the SRS system (if equipped.)
WARNING All SRS wire harnesses are covered with a yellow insulation. Read the SRS precautions found in this section and install the short connectors as described.
  1. Properly drain the cooling system.
  2. Disconnect and plug the heater hoses at the firewall.
  3. Disconnect the heater valve control cable.
  4. Remove the heater unit attaching nut on the firewall.
  5. Remove the dashboard as follows:
    1. Remove the center panel.
    2. Disconnect the wire connectors at the fuse box.
    3. Disconnect the sunroof switch connector, if equipped.
    4. Disconnect the ground cable at the right of the steering column and the power mirror switch wire connector.
    5. Remove the side air vent knob and face plate.
    6. Remove the screws attaching the air vent control lever.
    7. Remove the center panel, radio and heater control head.
    8. Remove the gauge upper panel (4-door) or instrument panel (3-door).
    9. Disconnect the speedometer cable.
    10. Remove the center upper lid.
    11. Remove the side defroster garnishes on both ends of the dash.
    12. Lower the steering column.
    13. Remove the dashboard mounting bolts.
    14. Lift and remove the dashboard assembly.

  6. Remove the heater duct.

Fig. Fig. 1: Removing the heater duct assembly

  1. Remove the steering column bracket and duct assembly.
  2. Remove the heater assembly mounting bolts.
  3. Remove the heater assembly and remove the heater core.


Fig. Fig. 2: Removing the heater case assembly


Fig. Fig. 3: Removing the heater core from the heater case

To install:

  1. Install the heater core into the heater unit.
  2. Install the heater assembly and the attaching bolts.
  3. Install the heater duct and steering column bracket.
  4. Install the dashboard assembly. Tighten the mounting bolts until just snug.
  5. Raise and attach the steering column.
  6. Install the center upper panel.
  7. Connect the speedometer cable and install the instrument gauge assembly.
  8. Install the control head, radio and center panel.
  9. Install the side vent and face plate.
  10. Connect the ground cable at the right of the steering column and the power mirror switch wire connector.
  11. Connect the sunroof switch connector, if equipped.
  12. Connect wire connectors at fuse panel.
  13. Install the heater unit attaching nut on the firewall.
  14. Connect the heater valve control cable.
  15. Connect the heater hoses at the firewall.
  16. Connect the negative battery cable.
  17. Fill, bleed and leak check the cooling system.

Oct 05, 2010 | 1991 Honda Civic

1 Answer

My dash lights don't work all the time.

Theres not much u can do without the wiring diagrams, tools & knowhow on an intermittent electronic problem. I suggest u "bite the bullet" get it done properly. Theres a motherboard behind the dash that u have no way of checking on your own. Good luck

Apr 06, 2017 | 1992 Cadillac Seville

1 Answer

Speedometer not working service engine soon light on

I would guess there is a relation between the inop speedo and the service soon light being on. Push OFF and WARM on the climate control panel and hold down together for 5 sec to read codes.engine and transmission require speed input to set engine/trans parameters accordingly. The car car is safely performing in a back up mode until repairs are made

Apr 04, 2009 | 1993 Cadillac Seville

1 Answer

95 seville sls jumps out of gear, losses fire, no speedometer

It may sound like a bunch of different problems but when in reality it could be just a VSS - vehicle speed sensor . The PCM/ ECM use's this information for shift point's , speedometer setting an someother systems on the vehicle . When you say it cut's off an will not start like it has no fire , what do you mean . Explain ! When you turn the key to start the starter engages the engine an spins it over but does start an run ? Or when you turn the key to start nothing happen's ? Traction control wouldn't work either with a bad VSS . You should take it to a qualified repair shop that has a professional type scanner to view codes in all the modules . If when you turn the key to the start position the starter does engage the engine an spin's it , no key or lock cylinder problem

Nov 19, 2017 | 1995 Cadillac Seville

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

50 people viewed this question

Ask a Question

Usually answered in minutes!

Top Cadillac Experts


Level 3 Expert

76846 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22246 Answers

Ronny Bennett Sr.
Ronny Bennett Sr.

Level 3 Expert

6924 Answers

Are you a Cadillac Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides