Hello good afternoon, I have a 2004 Chevy express 1500 cargo van that's been in the family since bought new back in 2004 and the signal indicator is blinking really fast. It blinks so fast that it stays solid most of the time so we have to manually operate the signals are self. It has been doing this for many years but since my father has retired his business and given the van to me, it drives me nuts and doesn't help me focus on driving since it's hard to steer a big vehicle like that and operate the turn signals manually.
I know bulbs could be the culprit but I have already checked them all.
Thank you for reading, all responses are greatly appreciated!
Are they OEM bulbs or LED? If they're OEM and you're certain that they are good, my guess would be either a bad flasher or bad wiring. If you changed out the OEM for LEDs then it could be the OEM flasher or standard LEDs. There are modified flashers for LEDs that will make them flash properly. There are CANBUS style LEDs that may help solve your problem also.
this vehicle uses class 2 data communication, not CAN bus.
Yea their the original bulbs. Should I try just replacing all of the bulbs with new ones to see if it will fix it?
were the bulbs replaced with LED?
No, the bulbs are OEM.
The first thing I would do is disassemble, inspect and clean the multifunction switch.
Turn Signal/Hazard Lamps
The IGN E 10 A fuse in the underhood fuse block supplies battery positive voltage to the turn signal switch assembly. Ground for the hazard switch is from G302. The FLASHER 15 A fuse in the underhood fuse block supplies battery positive voltage to the turn/hazard flasher module. When the turn signal switch is placed in either the left or right position, a voltage signal is completed from the turn signal switch to the turn/hazard flasher module. When the hazard flasher switch is activated, a ground signal is completed from the hazard switch to the turn/hazard flasher module. The turn/hazard flasher module then sends an on-off voltage signal to the appropriate turn signal lamps, or to all turn signal lamps for hazard operation through these fuses:
- DR TRN MIR, in the body fuse block
- PASS TRN MIR, in the body fuse block
- LR STOP/TRN, in the body fuse block, and in the underhood fuse block for RPO UY7
- RR STOP/TRN, in the body fuse block, and in the underhood fuse block for RPO UY7
- LR TURN in the underhood fuse block
- RR TURN in the underhood fuse block
- LT DRL/TRN in the underhood fuse block
- RT DRL/TRN in the underhood fuse block
The audio chime is also activated when the turn signals are on. When the hazard switch is pressed, all turn signal lamps will flash including both IPC turn indicators. The front turn signals are grounded at G100 and G101. The rear turn signals are grounded at G401 and 402. The mirror turn signals are grounded through a splice pack at G347.
The bulb socket itself could have corrosion resulting in an open circuit. You will need to probe the circuits with a multimeter to see where the fault lies. It could be a bad flasher module. (located behind the driver's knee panel).
