Turbo Dodge Forums banner

1 - 19 of 19 Posts

·
Registered
Joined
·
60 Posts
Discussion Starter #1
i got a 88 omni with a 89 caravan 2.5l turbo motor in it..i jsut fired it up a few days ago ran it for say 20 min ran find now as soon as i hook up the battery the ecm starts to smoke...i fired it and it still runs but the ecm starts smoking well it starts as soon as the battery is hooked up...ive checked all the wireing and it all looks fine...any ideas would be awsome..thanks
 

·
Administrator
Joined
·
24,829 Posts
You have a short to voltage,short to ground or lost a ground and the current found an alternate path.
I would start by disconnected high draw devices from the system to try to isolate the problem.Disconnect all Alternator leads,the ASD Relay, Cooling Fan and A/C Compressor electrical connectors and see if the smoking stops when you connect the battery.If it does with the battery disconnected reinstall each of the disconnected leads 1 at a time and reconnect the battery each time until the problem reappears.If it is related to the ASD unplug the fuel pump,coil +,injector harness and O2 sensor then reconnect 1 at a time as you did previously to isolate which component is creating the problem.
Check the O2 Sensor wires very carefully,the heater wire may have come in contact with the exhaust and they melted together giving you a short to ground.
If you were not able to isolate the problem with the above diagnostics you are going to have check all the power feeds and grounds at the controller connector and then you need to check that voltage is not present at any other cavities.It is also possible that the controller is shorted internally.
Are you using the 89 SMEC?
You say the vehicle will run,was the check engine lamp on? If so can you retrieve the fault codes? Everytime you disconnect the battery you are clearing the codes so you will have to check quickly with the battery connected but this may narrow down the search if the above diagnostics did not achieve any positive results.
 

·
Administrator
Joined
·
24,829 Posts
You guy's make me laugh!!!!!
 

·
Registered
Joined
·
60 Posts
Discussion Starter #5
u guys are funny....but seriousley i tryed about everything i could do unpluuged the entire harness and the only way i could get it too not smoke was to cut the red wire that feeds into the corner of the ecm on the big plug..any idea what that is supose to be for...i think i might go get a new harness and ecm...
ps thanks for the help
 

·
Registered
Joined
·
60 Posts
Discussion Starter #7
go with NAJ??

ive done everything he has already told me to try and it still smoke..i have the harness out of the car with nothing but the ecm hooked up to a ground and a power and it smokes still the only way it will stop is to cut a red wire that goes into the ecm in the corner....
my question now is im going to the recker to get a new harness and ecm...what years will work for what i need..heres what they have

88 lebaron 2.2 turbo auto tranny
87 lebaron 2.2 turbo auto tranny
85 lebaron 2.2 turbo auto tranny
91 shadow convert turbo auto tranny
90 acclaim 2.5 turbo auto
they also have a bunch of 88-91 shadows, omni, daytonas with the 2.2 na some auto some standard trannys...and help would be great aswell as does anyone know how to repin the connector at the dash or should i try to get a bit of wireing from under the dash too...thanks alot...
 

·
Registered
Joined
·
3,619 Posts
maybe the ecm is shorting out internally? id say try a new ecm and if it does it again then replace the harness. but that would suck cause chances are you fried the ECM if it was the wire harness that caused the problem. or you could just replace both and be safe
 

·
Registered
Joined
·
60 Posts
Discussion Starter #9
i had thought about the ecm shorting out itself...kinda wierd it was jsut fine when i ran it last then i got to give e quick fire and then the smoke..but the real wierd part is it still runs...i dont want to take the chance and fry another ecm i can get the new harness for 40bucks id rahter do it right and not buy another ecm i had thought about doing it that way but the harness is already out now too...will i need to grab any different sensors for the new harness and ecm or are they the same...thanks again
 

·
Administrator
Joined
·
24,829 Posts
You have yet to answer my question about which year controller and wiring you are using.
Do you own a Digital Volt/Ohmeter?
Locating shorts and opens in electrical circuits is a time consuming,tedious task and requires a lot of patience.
If you feel you are able to do this I can help you diagnoise it.
The reason it stopped smoking when you cut the red wire is that is a constant power feed to the controller and you took it away,you did not fix or locate any problem by doing that.
When you had ALL the alternator leads,ASD,cooling fan and AC electrical connectors unplugged it still continued to smoke? If so there is something in the system that is drawing a current that should not be and it must be isolated. Amperage burns wires,not Voltage.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #11
hey sorry i am running the 89 caravan ecm and harness...thats what was init when i got it...i have unplugged everywire in the car ..i mean the alt the firewall connector everyrelay fan all connectors fuel injection o2 map startereven the little plug on the ecm....the only wires still plugged in are the big plug on the ecm and the one power wire off the battery terminal...i have the harness pretty well out of the car...the problem is i got the car from someone who did most of the swap and could not finish it...i think at this point it would be easier to get a new harness and a ecm...i can do wireing ok but i hate trying to figure out other peoples mess..i know the guy had repinned the firewall plug but he said that was it.....thanks again for all the help
 

·
Administrator
Joined
·
24,829 Posts
If the harness was cut and spliced that could be a problem trying to figure it out.
The RD wire you said you cut that stopped it from smoking is in cavity #41(the 3 cavities next to it are open) of the 60 pin connector(SMEC) and is the battery feed-charging voltage sense and that wire is from the battery,thru a white fuseable link in the harness and splits to the controller and ASD relay.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #13
yeah i think its going to too hard to figure out what he he changed..i can get the harness for 20 bukcs and a ecm for 45 so im going to get new ones tom...what harness would be best for me...and should i grab the harness in the cab..thanks
 

·
Administrator
Joined
·
24,829 Posts
If you can get the harness's and controller that cheap go for it.I do not know which harness's fit which vehicle but if you can get the interior and dash harness you probably should,you never know when you may need something from one of them. Do not throw out your old one because the connector pigtails are hard to find.
Keep us posted on how evrything goes.
 

·
Registered
Joined
·
60 Posts
Discussion Starter #15
ok thaks alot for all your help....if it all goes good i should have it going sat night if not it will be monday night..and ill let u know how it all goes...thanks again
 

·
Registered
Joined
·
3,619 Posts
What is your battery voltage at? maybe its overcharging and this is causing it? but im sure theres somekind of protection for the ecm
 

·
Registered
Joined
·
60 Posts
Discussion Starter #17
i know its not charging as i dont even have the alt hooked up....i think if it was that bad the fusible link would go but not sure...thanks for the idea...
 

·
Registered
Joined
·
60 Posts
Discussion Starter #18
ok well i got my new harness its from a 90 dynasty i got it all in and i cant get spark now...i dont have the fire wall harness done as it will be a big job so i jsut put power to the ecm power..well i think it is ...the realy on the fenderwall clicks and the coil gets power for a few seconds then the realy cliks back off and nomore coil power...but no matter what i do i get no spark...and idea...does more that one wire have to be hooked up from the firewall plug to make it spark...all the underhood wireing is hooked up with the exception of the day time running light moduel cause i for got it at the wreckers....and ideas or did i get a bad ecm from the wrecker....
 

·
Administrator
Joined
·
24,829 Posts
1990 uses a totally different controller.
90 uses a SBEC, 1 60 pin connector
88-89 uses a SMEC 1 14 pin connector and 1 60 pin connector
Chances are the wires in the bulkhead connector are in different locations.
 
1 - 19 of 19 Posts
Top