Courtesy lights staying on
11-08-2010, 11:30 PM
#1
Racer
Thread Starter
Courtesy lights staying on
Since the courtesy lights are standard between the Z's and other 91-93cars, I'll post this question here. My wife's 91 Coupe just started having the courtesy lights staying on. I thought that it might be the door ajar switches and checked them but no result. Lights stay on. I have both manuals, so I started the diagnostic check for that problem. So far, I have eliminated the light switch and the courtesy light relay which I had already replaced. Tomorrow, I will check the CCM for ground and play with the door key diagnostics. The CCM shows no codes at all. Other than the key switches and the CCM, anything else? I have checked the hatch switch as well. The other thing that I was thinking about was the diode relay module. I found one in the back area of the hatchback by a relay in the foam. According to the schematic, there is one by the stack under the right hand side bolster. Are there two of them? I pulled the diode module out and the lights went out. Thoughts?
11-09-2010, 12:44 AM
#2
Tech Contributor
Did you press down rear window hatch plunger when both doors are closed 
How did you rule out the door ajar switches?
How did you rule out the door ajar switches?
Last edited by Goldcylon; 11-09-2010 at 12:47 AM.
11-09-2010, 12:39 PM
#4
Instructor
Courtesy lights staying on
Since the courtesy lights are standard between the Z's and other 91-93cars, I'll post this question here. My wife's 91 Coupe just started having the courtesy lights staying on. I thought that it might be the door ajar switches and checked them but no result. Lights stay on. I have both manuals, so I started the diagnostic check for that problem. So far, I have eliminated the light switch and the courtesy light relay which I had already replaced. Tomorrow, I will check the CCM for ground and play with the door key diagnostics. The CCM shows no codes at all. Other than the key switches and the CCM, anything else? I have checked the hatch switch as well. The other thing that I was thinking about was the diode relay module. I found one in the back area of the hatchback by a relay in the foam. According to the schematic, there is one by the stack under the right hand side bolster. Are there two of them? I pulled the diode module out and the lights went out. Thoughts?
Tomcat 74
91 ZR1 #906
11-09-2010, 02:28 PM
#5
Racer
Thread Starter
Interesting. Since I didn't want to drain the battery, I disconnected it several times. I am currently checking the ground path. The CCM shows no codes at all. What is surprising is that it was working fine, then my wife drove it around and it just started.
11-09-2010, 06:52 PM
#7
Racer
Thread Starter
Both door switches were bad and finally got it working right. I had forgotten about it but there is a diagnostic test on the CCM that determine if the switches are good or bad. The drivers door was pretty straight forward but the pax door had an intermittent on and off that was ticking me off. I finally opened the door panel off and the one of the wires was partially broken, causing it to come on and off. Nailed that sucker down! All's good with the car now.
