Question about 1986 Jeep Comanche

1 Answer

I turn ignition switch "on" and weird electrical problems happen.

I just overhauled a 1986 Jeep Comanche with a 2.8 L V6.
All said and done runs great. Yesterday I tried to turn it on and it didn't even kick or do ANYTHING. Checked it out again, used a test light to check all of my connections. I made sure the negative cable had a really good connection and it started working again. When I turn the ignition to on and fiddle with the lights or anything the sensors all turn dead (voltometer, oil pressure gauge, tempurature gauge everything except gas gauge). They work until I turn the lights on or touch any of the switches on the dash. I tried doing a brake booster check (holding the brake pedal down while shutting off the engine) and to my surprise, the truck stays idoling until I take my foot of the brake. THIS IS REALLY SCREWED UP.
The truck has been sitting outside so much that the fuse relays may have gotten wet and shorted something. But don't let this fool you. It didn't have any problems until one day it didn't start up. Now the lights won't turn on and when I try to turn them on the electrical system gets all screwy.
Please help, this is the final step to a 2 year project of mine. I'm so close to finishing it except this happened. Please give me all the info possible or any leads as to what to do.
-Thank You

Posted by on

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Jeep Master
  • 22,041 Answers

Wiring fault somewhere along the line,you have a backfeed into the ignition circuit when the lights are on by the description ??well all very well diagnosing it but its the finding it now----could be anything from a single pole bulb in the place of a double pole bulb in the rear side light/stoplight ,well on europeon model with seperate light lens/colours ,but stateside on older vehicles that are home grown you use a weird set up with stop light and indicators all doing funny things,i know this because i have had to rewire the things for an import to get mechanical inspection certificates.So you will have to look for it somewhere ,check rear light earths to chassis as well ,and the best of british mate because iam colour blind so you can imagine the problem i would have trying to do this ( red/green).Another tip if you have a towbar check the wiring plug/loom for chaffing in the chassis as this can cause feed back as well .i only get one reply by the way if you need more help so please dont think i have ignored you after one reply i just cant post it

Posted on Jan 16, 2009

1 Suggested Answer

  • 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

Add Your Answer

Uploading: 0%


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



Related Questions:

1 Answer

I have a 1989 jeep camanche 2w dr 4.0 it was running great then yestrday it wouldnt start it turns over and has fuel in it and the fuel rail seems to have a good amount of pressure

you need to check the following parts related for ignition, 1) check the terminal of your battery, 2) check your fuel pump, 3) check your starter and 4) ignition switch...after you check all those parts, i'm hoping you can locate the problem of your vehicle...goodluck

Feb 05, 2011 | 1991 Jeep Comanche

1 Answer

Motor shut down, motor turns over, spark at the coil, ignition fuse is good, just won't start and run.

If when you try to start your venicle does it do a fast turn over if so then probably bad timing belt or chain, if it catches like it tries to start then check fuel filter and or pump.

Oct 23, 2010 | 1986 Jeep Comanche

1 Answer

87 jeep comanche blinkers, wipers, a/c and horn don't work

Check the fuses,and then look at the fusible links,most likely on the starter,if they are good,replace the ignition switch.

Apr 12, 2010 | 1987 Jeep Comanche

1 Answer

I have 85 jeep camanche will run but wontshift

Check your pin in the yolks i had a pin come out 1/2 way we fixed it ourself he took it some where in cleveland to get. A new pin put it in ran fine after that

Mar 04, 2010 | 1986 Jeep Comanche

1 Answer

Is this an electrical problem..or not?

2 things posable here

daylight running lighr controller is pooched

or you have a bad multi switch on the columb

try a salvage yard for parts

if you move the signel indacator do the lights go out in between position if wiggled pushed in or pulled out of yes switch likely bad

Jan 08, 2010 | 1989 Jeep Comanche

2 Answers

I need to know where all the vacume lines go on a 1986 comanche 2.8l v6

Most vehicles have a diagram on the underside of the hood that shows the vacuum line routing. Just open your hood and look up!

Sep 13, 2009 | 1986 Jeep Comanche

1 Answer

What is the firing order of a jeep comanche 1986 v-6 engine?

if its a 2.8 the firing order is 1-2-3-4-5-6 and the distributor rotates:clockwise if you lose this look ontop of your intake manifold and it has it stamped on it by the number to intake.

Mar 21, 2009 | 1986 Jeep Comanche

2 Answers

1988 jeep comanche will start only when you hold tumbler in the start position, when you relese it, engine stops.. engine is a 4.0 auto, fuel injected 4x4

If the car has a resistor coil with a ballast resistor to drop voltage from 12 to 8 then check the resistor wiring. When you engage the starter tumbler it by passes the ballast resistor and sends 12 volts straight to the eight volt coil to get good spark. When you release it the 12 volts goes through the resistor to 8 volts and then the coil. If there is a fault in this circuit the engine stops. Jump the 12 volts straight to the coil and start it. If it keeps going the ballast circuit is faulty. Paul

Jul 27, 2008 | 1986 Jeep Comanche

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

78 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jeep Experts


Level 3 Expert

70346 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22041 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

6869 Answers

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

Answer questions

Manuals & User Guides