Jump to content

'89 Reatta, have lost most of my dash and all of my interior lights


Recommended Posts

fun car guy

Okay, the parking lights work but the fog lights do not come on at all except as turn signals.  I can't seem to go from low to high headlights, assuming the cruise control stalk is also the dimmer switch as it does have a headlight icon on it.  Seems strange to have a switch to turn the headlights on and another to turn them off.

Yes, you're absolutely right, I should focus on one thing at a time.  It was just that I couldn't do any more with the fuses and decided to try the experiment to see if the injectors were all working, it was very revealing!

Link to post
Share on other sites
Ronnie

I think you have proven the BCM is not working with your test of the fog lights and high beams. When you push the button for the fog lights your are just telling the BCM you want the fog lights on and the BCM is supposed to pickup the relay to turn them on. The same is true when you pull the turn signal lever to activate the high beams, or open a door to turn on the interior lights. The BCM controls all of that plus the IPC and CRT. That is the reason none of that stuff is working. Not much on the Reatta will work without the BCM except the engine. The engine is controlled by the ECM.

 

In my opinion either there is a fuse that powers the BCM blown or the BCM is defective. That means knowing all the fuses are good is the first order of business. You didn't mention the fuses so I assume you haven't done anything about them yet. Good luck!

Link to post
Share on other sites
fun car guy

So I have no fog lights but seem to have all other outside lights working.  I'm thinking I'll check the other fog light for a burned out or missing bulb.  Still unsure as to how to switch from high to low beams.

 

Link to post
Share on other sites
fun car guy
On 4/30/2021 at 6:49 PM, 2seater said:

Are the two cylinders that don’t change the idle on the same coil? You can turn injectors on and off individually in diagnostic override mode right from the drivers seat to check them without involving the ignition. Just a suggestion, once the engine is warmed up and idling, disconnect the IAC connector to keep it from changing the idle when trying to isolate a dead cylinder(s). 

That's a very good question and I'll look into that.  I'm also going to try to hear the clicking of the injectors with a screwdriver to confirm my suspicion.  I didn't disconnect the IAC, just pulled the wires from the coil one at a time and saw a change with four of them and no change with the ones I suspect.  I also dumped a whole bottle of Sea Foam in the gas tank hoping it might clean them and I wouldn't need to replace them.

Link to post
Share on other sites
fun car guy
8 hours ago, Ronnie said:

I think you have proven the BCM is not working with your test of the fog lights and high beams. When you push the button for the fog lights your are just telling the BCM you want the fog lights on and the BCM is supposed to pickup the relay to turn them on. The same is true when you pull the turn signal lever to activate the high beams, or open a door to turn on the interior lights. The BCM controls all of that plus the IPC and CRT. That is the reason none of that stuff is working. Not much on the Reatta will work without the BCM except the engine. The engine is controlled by the ECM.

 

In my opinion either there is a fuse that powers the BCM blown (there are several of them) or the BCM is defective. That means knowing all the fuses are good is the first order of business. You didn't mention the fuses so I assume you haven't done anything about them yet. Good luck!

I see, so the BCM is the master, thanks for telling me that, I just wish I knew the location of all the suspects.  I've always suspected one or more blown fuses were the cause.  I just have to get to the parts store, get an assortment of fuses and a simple tester of continuity to check them.  I'm assuming the body fuse is the main one but will do as you suggest and test all other than the circuits I know are working.  I'll let you know what I find out.  Thanks

  • Like 1
Link to post
Share on other sites
Padgett

This is why I have an OTC 2000 scan tool with a 93 Pathfinder (includes GM) cartridge. It can be plugged into the socket marked "do not remove" and essentially do everything the CRT diagnostic mode can. Can also use parts from Moates.net.

Link to post
Share on other sites
Ronnie
12 minutes ago, Padgett said:

I have an OTC 2000 scan tool with a 93 Pathfinder (includes GM) cartridge.

I've saw those scan tools advertised on eBay but never used one. Are they capable of reading BCM codes as well as ECM codes?

Link to post
Share on other sites
Padgett

An OTC 2000. can read the same things the built in diagnostics can

  • Thanks 1
Link to post
Share on other sites
fun car guy
On 5/1/2021 at 12:28 PM, Ronnie said:

I think you have proven the BCM is not working with your test of the fog lights and high beams. When you push the button for the fog lights your are just telling the BCM you want the fog lights on and the BCM is supposed to pickup the relay to turn them on. The same is true when you pull the turn signal lever to activate the high beams, or open a door to turn on the interior lights. The BCM controls all of that plus the IPC and CRT. That is the reason none of that stuff is working. Not much on the Reatta will work without the BCM except the engine. The engine is controlled by the ECM.

 

In my opinion either there is a fuse that powers the BCM blown or the BCM is defective. That means knowing all the fuses are good is the first order of business. You didn't mention the fuses so I assume you haven't done anything about them yet. Good luck!

.

I have to correct myself as previously I said the fog lights don't work other than as turn signals which is wrong of course, the fog lights don't work at all. 

I just bought an assortment of fuses and replaced the body fuse even though the old one tested as good so yes, I'm going to hunt out all fuse blocks, test them and if the BCM is defective I hope it's not too difficult to replace and I can find a used one that's not too expensive.  Thanks for clarifying the role of the BCM, Ronnie.

  • Like 1
Link to post
Share on other sites
Padgett

Does the CRT work ? If not that is the place to start.

Link to post
Share on other sites
Ronnie
On 5/2/2021 at 5:53 PM, fun car guy said:

I just bought an assortment of fuses and replaced the body fuse even though the old one tested as good so yes, I'm going to hunt out all fuse blocks, test them and if the BCM is defective I hope it's not too difficult to replace and I can find a used one that's not too expensive.

Since you haven't made a comment in several days I can only assume replacing the body fuse fixed your problem. Congratulations on an easy fix!

Link to post
Share on other sites
fun car guy

Ronnie I wish that were so but major events in my family have put my car on the back burner.  Also, the weather has been especially cool and damp but I appreciate your optimism.  Believe me, when I do figure this out, everyone in this community will know.  However I do plan on getting back to it before long, find the blown fuse (or fuses) and be back in business, one way or another.  I'm really looking forward to next summer when all the fuss about covid has eased considerably and I have my black beauty on the road with people asking me what kind of car it is.

  • Like 1
Link to post
Share on other sites

So I checked all the known fuses (the block on the right side of the console and the hidden one below it.)  I found all fuses good with the exception of defog which had gotten hot, replaced  it but still no dash or interior lights.  Assuming there are no more fuses, I'm going to check the fusible links next. 

Also, after checking for air, spark and listening to the injectors to be sure they're working, I'm thinking I may have one or more bad engine mounts allowing the engine to move.  When it's cold it actually makes the exhaust occasionally knock against the body. 

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...