20 Most Recent 1986 Cadillac DeVille Questions & Answers

Well you need to post more info. What mode is the climate control in? what is the temp set to? Is the engine warmed up to operating temp? Is the coolant filled to the top of radiator and are the hoses going to the heater warm/hot when engine is running?

The most likely cause is a bad sensor, tho there is a small chance of a computer or wiring problem. Check the connector at the sensor, if it's not damaged/corroded I would replace the sensor. You can probably find a used one from a junkyard or on ebay pretty cheap. If you need further help, I’m available over the phone at https://www.6ya.com/expert/oscar_403cc49e0f00cda7

There is an additive for this. But an 86? still worth a try. May give you a little more time.

Counter-clockwise to loosen, whether it is the flywheel or crank pulley. Use NEW bolts and red Locktite when you reinstall.

counter clockwise.

did you change the fuel filter? could also be the cat converter is blocked up.

I need to know what type and year of car....

ITS A TIGHT SPOT

Should be in with a box of relays on the back side of the drivers side inner fender. If you have internet access you can go on line and just ask the search engine where it is at and it will give you pages of mostly useless info but you should be able to sort through it and find it. Try and find a print out of the fuse and relay locations. I had a 93 and I downloaded where all the relays were located and all the fuse locations. If none of that helps go to a local parts house and they can look it up or buy one of those CHILTON Books on it. They are very helpful at times. Col. Dana Gillespie

My 1986 caddy does the same thing. Did you have any luck fixing yours? Mike

if u havent fixed it by now usually it the fan module behind the front left headlight to acess remoce the coolant resivor and the left side turn signl marker their are 2 7mm screw and connectors on each end but u have to remove the sensor input signal wire to se if the fans come on 1st part of the diag do not replace the bcm til u checkl it out 1st usually it is the fan maoule at fault not bcm