Audio/Visual Electronics Wired up? Everyone's got some sort of electrical modification... let's hear about it here.

New Radio won't work after ECU got replaced.

Thread Tools
 
Search this Thread
 
  #1  
Old 07-14-2012, 04:34 PM
sirtwist2's Avatar
Junior Member
Thread Starter
Join Date: Feb 2012
Location: New England
Posts: 71
Default New Radio won't work after ECU got replaced.

Greetings,

I have a 1993 Accord LX. I replaced the factory stereo with a Kenwood several months ago. It was the first time I had done anything like this, I ordered it from Crutchfield, followed the directions, soldered the connections, it went relatively well, and worked fine.

About a month ago, during an extremely heavy rain fall, the drain in front of my house backed up and I had water into my car about halfway up the doors and about to the bottom of the shifting console. The car would try to start but wouldn’t. A local garage diagnosed the ECU as having gotten wet and needing replacement. I found one at a local junkyard. The garage replaced the ECU and the car worked well . . .

Except, the radio kept turning on and off and resetting the preselect stations. Now, it won’t turn on at all. The water didn’t get up to the dashboard or to the radio. I removed the radio and checked the connections, everything looked good, reconnected the radio, still won’t work. I put the factory radio in and it works fine. I had the car audio installer at Best Buy check the new Kenwood radio, it works fine. Just to throw a monkey wrench into the issue, the car clock on the dash board also isn’t working right, it won’t keep the correct time.

Does the ECU have anything to do with the radio and clock? Is it possible the ECU isn’t delivering the correct amount of power to the new radio but enough for the old radio? I tried checking the power at the dashboard radio plug, either I’m not doing it right (I’m not good with electricity so a distinct possibility) or my volt meter isn’t working right (it’s old, so also a distinct possibility) because I get readings all over the place.

What else should I check?

Also, once the original ECU is dried out, is it possible it will start working correctly?

Thanks for any help!
 
  #2  
Old 07-14-2012, 06:28 PM
redbull-1's Avatar
Super Moderator
Join Date: Oct 2010
Location: United States
Posts: 7,083
Default

The ECU wouldn't have anything to do with the radio.

If your readings with the volt meter is all over the place, I would check the under-dash grounds first; and that they are clean and secure. Remove the ground bolts, use some sandpaper to clean both the chassis surface and the ground wire connector and re-attached.

Check ground locations G401 and G402. See this links showing the locations:

Honda-Tech - View Single Post - Electrical gremlins in a 93 Accord LX
 
  #3  
Old 07-15-2012, 01:16 AM
sirtwist2's Avatar
Junior Member
Thread Starter
Join Date: Feb 2012
Location: New England
Posts: 71
Default

I'll check those grounds tomorrow but if there was a problem with the grounds, the factory radio wouldn't work, would it?
 
  #4  
Old 07-15-2012, 01:41 AM
redbull-1's Avatar
Super Moderator
Join Date: Oct 2010
Location: United States
Posts: 7,083
Default

When you stated the voltage readings were all over the place, the current (flow of electricity) was probably not consistent. It may be that your Kenwood has an internal amplifier requiring a higher draw of current than the stock stereo.
 
  #5  
Old 07-15-2012, 06:04 PM
keep_hope_alive's Avatar
Super Moderator
Join Date: Dec 2009
Location: Quad Cities, IL
Posts: 3,279
Default

good diagnostics. the clock is tied to memory. sounds like that wire/connection is bad at the passenger fuse box. it is possible the water caused corrosion there.
 
  #6  
Old 07-17-2012, 11:54 AM
sirtwist2's Avatar
Junior Member
Thread Starter
Join Date: Feb 2012
Location: New England
Posts: 71
Default

Originally Posted by redbull-1
The ECU wouldn't have anything to do with the radio.

If your readings with the volt meter is all over the place, I would check the under-dash grounds first; and that they are clean and secure. Remove the ground bolts, use some sandpaper to clean both the chassis surface and the ground wire connector and re-attached.

Check ground locations G401 and G402. See this links showing the locations:

Honda-Tech - View Single Post - Electrical gremlins in a 93 Accord LX
Thanks for the responses!

I checked ground locations G401 and G402. They looked ok, I wiped them down, wiped down the screw holes and reattached everything.
The factory radio works and the new radio still doesn't work.

Any other ideas?
 
  #7  
Old 07-17-2012, 12:09 PM
redbull-1's Avatar
Super Moderator
Join Date: Oct 2010
Location: United States
Posts: 7,083
Default

Check the 7.5A back-up fuse in the under hood fuse box. A picture is shown in this link:

Troubleshooting ECU Symptoms.

That back-up fuse is for the ECU, Clock, TCU, and stereo.

Let me know how things go. Good luck.
 
  #8  
Old 07-17-2012, 02:50 PM
sirtwist2's Avatar
Junior Member
Thread Starter
Join Date: Feb 2012
Location: New England
Posts: 71
Default

Originally Posted by redbull-1
Check the 7.5A back-up fuse in the under hood fuse box. A picture is shown in this link:

Troubleshooting ECU Symptoms.

That back-up fuse is for the ECU, Clock, TCU, and stereo.

Let me know how things go. Good luck.
Checked that fuse, it's fine.

Any other suggestions?
 
  #9  
Old 07-17-2012, 03:31 PM
redbull-1's Avatar
Super Moderator
Join Date: Oct 2010
Location: United States
Posts: 7,083
Default

Are the volt meter readings still fluctuating at the radio plug? What about at the driver's side under-dash fuse box? Use the volt meter on some of the fuses (the top of each fuse has areas to get a reading).

Also check that the wire harness connectors to the fuse box are secure.
 
  #10  
Old 07-21-2012, 11:55 AM
sirtwist2's Avatar
Junior Member
Thread Starter
Join Date: Feb 2012
Location: New England
Posts: 71
Default

Originally Posted by redbull-1
Are the volt meter readings still fluctuating at the radio plug? What about at the driver's side under-dash fuse box? Use the volt meter on some of the fuses (the top of each fuse has areas to get a reading).

Also check that the wire harness connectors to the fuse box are secure.
Thanks very much for your help!

No, the volt meter readings are not fluctuating anymore. The reading from what I think is the power wire is 00.1mv. This doesn't seem very high, but the factory radio still works, although when I turn the car off, the saved stations remain but when I turn the radio off, the saved stations do not remain. Also, the clock is keeping correct time now, don't know why. I'm still not sure that the volt meter is working right, tho.

There aren't any solid red wires going into the radio plug from the car, the wire that corresponds to the diagram from Crutchfield's is red and yello. Is there a diagram on here that shows the radio plug and what each wire does?
 


Quick Reply: New Radio won't work after ECU got replaced.



All times are GMT -5. The time now is 05:13 AM.