Allpar Forums banner

90 Imperial Anti theft

843 10
The dreaded anti theft issues. I bought the car, the set light was on when driving. Digital dash, radio, message center working. Battery was old, bought a new battery. Manual says to disable, use key to unlock doors. I have done this, no Digital dash or other, like radio. Sometimes the set light stays on which it means hood or trunk not reading shut. I have tried everything short of a .45 to the car. Any suggestions?

When I bought the car, it started, drove, and digital dash, radio worked. The old battery went dead, then, the dash went black, radio quit, and the anti theft killed the injectors. Bought a new battery, now the car cycles from running with "set" light on, no dash/radio for a couple days, then battery dead, clicking from module behind glove box, unlock with key, clicking stops. Have not had time to chase the issues, Chrysler service at dealer, WORTHLESS. Anyone under 40, clueless. SOS.....Black Cherry, striking condition, and makes a statement, sad I cannot figure this out.
Wheel Tire Car Vehicle Plant

Wheel Tire Automotive parking light Vehicle Car
Vehicle Car Tire Motor vehicle Wheel

Wheel Tire Car Vehicle Motor vehicle

Car Vehicle Motor vehicle Window Car seat cover

Car Vehicle Motor vehicle Hood Automotive design
1 - 11 of 11 Posts

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
16,968 Posts
Welcome to Allpar. There is a procedure for disabling the early security system & a procedure for troubleshooting it. The door key cylinder switches may be corroded enough where they aren't sending the disarm signal to the security module.
This was common after some years & being inside the door is pretty-much an outdoor environment.

The system can be disabled by unplugging the module once the engine is running. I have the Body Diagnostic Procedures book somewhere.

The passenger door and trunk latch also have the key cylinder 'disarm' switches.

 
  • Like
Reactions: M.G

·
Registered
Joined
·
96 Posts
Sorry to hear about your troubles, MG. I eyed the ad for your car while I was shopping--it's a really handsome vehicle. But somehow my gut just couldn't get over the security thing. I guess my gut was on point. However, don't get too discouraged. We all let ourselves in for these headaches when we buy old cars. Eventually, the issues get sorted out, and then we have a good story (and hopefully a good car) to show for it.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #5 ·
Another puzzle piece. I have gone through 3 brand new batteries. Within just a couple of days, the battery totally dead, tested and told battery has dead cell needs to be replaced. Nothing is on to drain battery. The anti Theft is still not disableling, the dash, overhead computer, and radio not powered on.
 

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
16,968 Posts
Is the charging system damaging the batteries with gross overcharging?
Something sounds very wrong and will need to be remedied before trying further electrical diagnosis.
Sleeve Font Engineering Advertising Brand
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #7 ·
When the car was delivered. It was running, digital dash and all electronics, radio, climate control, trip computer working. When I used the door lock, the car died. Battery was dead, when I jumped it, the ground cable was loose, which I did not know. It came off battery. I tightened, jumped it started, but none of the dash items work. Anti theft set light says on, as well as door open light when everything is closed or shut. Drove car today 10 miles, ran out fine, except no dash, radio, climate controls, or trip. Set lite stayed on.
 

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
16,968 Posts
I would try disconnecting, then reconnecting the battery again. Possibly some body module logic got scrambled?
There are switches in the front door & trunk lock cylinders that can corrode & become intermittent. Try working the key in the passenger door & trunk locks? Do you have an owners manual for this car?
 

·
Super Moderator
Joined
·
21,026 Posts
This is an odd situation. The security system should shut down the car, not just shut off items like the dash.
I wonder if the ignition switch is causing a problem. Does jiggling the switch wake the dash?
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #10 ·
This is an odd situation. The security system should shut down the car, not just shut off items like the dash.
I wonder if the ignition switch is causing a problem. Does jiggling the switch wake the dash?
I will have to try. It has a new platinum battery, 3 weeks old, the third one in 2 months. It has a parasitic drain. It will set overnight after driving, nothing on, and dead. It maybe the ignition switch. So confusing. Thanks for the reply.
 

·
Super Moderator
1966 Crown Coupe, 2016 200 S AWD, 1962 Lark Daytona V8.
Joined
·
16,968 Posts
We need to find the draw. The ignition switch may not the cause of the draw, but could explain the loss of the instrument cluster, etc.
The neg terminal on the battery was probably kept loose so it could be easily disconnected to prevent the battery from discharging. It may be better to do this than jump starting with jumper cables. I've seen sensitive electronics knocked-out from voltage spikes & surges.

The quickest way to find a draw is to have a 'visual indicator' such as a bulb in series between the battery post & the battery terminal as shown below:
Automotive tire Bumper Gas Auto part Electrical wiring

Begin unplugging fuses & possibly connectors until the bulb goes out. Find out what components are on the circuit that you just disconnected, one of them is either staying on or is shorted.
This is an esoteric motorcar. Probably build before most of those techs were born. Get a factory Service Manual if you can. I got one for a 1993, which may be similar to a 1990 in most respects.
The PDC (power distribution center) is the underhood fuse/relay box. The fuse box inside the car is called the Junction Block.
Rectangle Font Parallel Schematic Slope

Rectangle Font Parallel Slope Pattern

Font Parallel Pattern Rectangle Number

Schematic Font Rectangle Parallel Technical drawing

Product Font Schematic Rectangle Parallel

Font Parallel Rectangle Pattern Number

Schematic Font Parallel Rectangle Engineering
 

Attachments

1 - 11 of 11 Posts
Top