Electrical gremlins - help!
Drifting
Joined: Feb 2025
Posts: 1,768
Likes: 1,782
From: THE BEACH..
Pull the Alternator and get it tested, the other Battery was definitely wasted at that point.
A dead cell in a Battery will pull current from where it can, bog the Alternator, and make the car do some really odd things. Seen it a few times.
Clear codes, check Battery connections and grounds where you see them, get Alternator load tested to be on the safe side. See what happens after all that.
A dead cell in a Battery will pull current from where it can, bog the Alternator, and make the car do some really odd things. Seen it a few times.
Clear codes, check Battery connections and grounds where you see them, get Alternator load tested to be on the safe side. See what happens after all that.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,320
Likes: 3,927
From: Cape Coral, Florida
98 C5, 80k miles purchased about a year ago - been having a number of electrical problems the last few months.
1st issue I noticed was 8-9 months ago, was driving up a parking garage when it basically shut down with a message reading reduced engine power. I turned off the car, turned it back on, drove with no problems and never had this issue again (not sure if related to other issues)
My theory was that the battery was old as I wasn't sure when the previous owner had replaced it, and maybe some electrical module was just not getting enough power consistently. I replaced the battery with an optima red top, this was about 6 months ago.
What is a normal voltage range for the DIC to display? Before I replaced the battery, I noticed it would wildly range, would be low 13s when I started the car and steadily drop if I wasn't on the highway, lowest I saw was high 11s. After replacing the battery, would see 13.4 or so after starting up, and would hover around this for highway driving and drop to mid/high 12s anywhere else.
Couple other electrical issues to note, 1) the horn does not work, 2) the fuel pump will occasionally "pulse" and I will see the voltage drop about 1v. This happens consistently every few minutes, the fuel pump whine will pause for a split second and then resume at a louder volume before going back to normal. Not sure if this is normal.
The above are historical issues I am not sure / curious on, current issues below:
I used to daily drive the c5, circumstances changed a few weeks ago and the car ended up sitting for about 2 weeks without being driven. It got cold during this time, I am located in south FL and it dropped into the 30s. Went to start it up, heard click click click with no other motion.
I ordered a NOCO portable jump starter, when it arrived I went to jump it with the intention of driving for around an hour to charge up the battery. Car jumped fine, drove out of the garage onto the street (it was night), but the headlights would not activate. Parked the car again to try the next day.
This is now 2 days ago, I jump the car again while it's light, drive around 30 minutes on the highway to the store. During the drive I noticed a few things, 1) when I had first started the car and was at stoplights before reaching the highway, lights were flickering in the cabin, and 2) after getting on the highway a repeating clicking noise coming from in front of the steering wheel. Sounded like it was in the cabin or very close to it, and in front of and to the right of where I was sitting. 3) the security light on the dash came on halfway through the drive, 4) as soon as I got off the highway the voltage on the DIC rapidly dropped from low 13s to low 12s and got into the 11s when I was at a stoplight, so it was clearly not holding a charge.
I come back out of the store 20 minutes later and the car will not start. I pull out the portable jump starter (which was supposedly between 1/4 and 1/2 battery) and the car still will not start, I hear it turning over very slowly for a few seconds before giving way to the click, click, click. I checked the jump starter again and it somehow ran out of battery, not sure if this was just the jump starter not having enough power to begin with or if the car drained it while attempting to start with a very weak battery.
At this point it was fairly late, I caught a ride home and left the car in the parking lot overnight. The next day (yesterday) I bought a new diehard gold battery and returned to the car to change the battery. It started no problem, however there was a check engine light and I was disappointed to continue hearing the previously mentioned clicking noise repeat on the drive back home.
Codes listed below:
P1516 H
P1517 H
P1518 H
C1255 H C
C1278 H
B0432 H
B0503 H
B0508 H
B2527 H C
B2588 H
B2593 H
B2721 H
B2723 H
B0361 H
B0363 H
B2252 H
B2282 H
B2284 H
(may have been more but the video I was taking got cut off).
Sorry to dump so much info here, not sure what might be causing the clicking noise or if it's even a real problem but electrical gremlins have been giving me headaches for several months so I wanted to check here.
1st issue I noticed was 8-9 months ago, was driving up a parking garage when it basically shut down with a message reading reduced engine power. I turned off the car, turned it back on, drove with no problems and never had this issue again (not sure if related to other issues)
My theory was that the battery was old as I wasn't sure when the previous owner had replaced it, and maybe some electrical module was just not getting enough power consistently. I replaced the battery with an optima red top, this was about 6 months ago.
What is a normal voltage range for the DIC to display? Before I replaced the battery, I noticed it would wildly range, would be low 13s when I started the car and steadily drop if I wasn't on the highway, lowest I saw was high 11s. After replacing the battery, would see 13.4 or so after starting up, and would hover around this for highway driving and drop to mid/high 12s anywhere else.
Couple other electrical issues to note, 1) the horn does not work, 2) the fuel pump will occasionally "pulse" and I will see the voltage drop about 1v. This happens consistently every few minutes, the fuel pump whine will pause for a split second and then resume at a louder volume before going back to normal. Not sure if this is normal.
The above are historical issues I am not sure / curious on, current issues below:
I used to daily drive the c5, circumstances changed a few weeks ago and the car ended up sitting for about 2 weeks without being driven. It got cold during this time, I am located in south FL and it dropped into the 30s. Went to start it up, heard click click click with no other motion.
I ordered a NOCO portable jump starter, when it arrived I went to jump it with the intention of driving for around an hour to charge up the battery. Car jumped fine, drove out of the garage onto the street (it was night), but the headlights would not activate. Parked the car again to try the next day.
This is now 2 days ago, I jump the car again while it's light, drive around 30 minutes on the highway to the store. During the drive I noticed a few things, 1) when I had first started the car and was at stoplights before reaching the highway, lights were flickering in the cabin, and 2) after getting on the highway a repeating clicking noise coming from in front of the steering wheel. Sounded like it was in the cabin or very close to it, and in front of and to the right of where I was sitting. 3) the security light on the dash came on halfway through the drive, 4) as soon as I got off the highway the voltage on the DIC rapidly dropped from low 13s to low 12s and got into the 11s when I was at a stoplight, so it was clearly not holding a charge.
I come back out of the store 20 minutes later and the car will not start. I pull out the portable jump starter (which was supposedly between 1/4 and 1/2 battery) and the car still will not start, I hear it turning over very slowly for a few seconds before giving way to the click, click, click. I checked the jump starter again and it somehow ran out of battery, not sure if this was just the jump starter not having enough power to begin with or if the car drained it while attempting to start with a very weak battery.
At this point it was fairly late, I caught a ride home and left the car in the parking lot overnight. The next day (yesterday) I bought a new diehard gold battery and returned to the car to change the battery. It started no problem, however there was a check engine light and I was disappointed to continue hearing the previously mentioned clicking noise repeat on the drive back home.
Codes listed below:
P1516 H
P1517 H
P1518 H
C1255 H C
C1278 H
B0432 H
B0503 H
B0508 H
B2527 H C
B2588 H
B2593 H
B2721 H
B2723 H
B0361 H
B0363 H
B2252 H
B2282 H
B2284 H
(may have been more but the video I was taking got cut off).
Sorry to dump so much info here, not sure what might be causing the clicking noise or if it's even a real problem but electrical gremlins have been giving me headaches for several months so I wanted to check here.
Do you have a DVOM and know how to use it ??…if not find an auto electric shop in your area….you may have a parasitic drain if your battery is dying…you don’t go by the DIC voltage…it reads about 0.4 volts lower than at the battery…see if your alternator is charging your battery and you should do a charging system voltage drop check of your charging system…a few videos on YouTube on how to do it.
