GM 4905 Turn Signal Relay/flasher unit

[pabusnut]

I have found turn signal flasher units that work with LED turn signals, which I have installed on my bus.
Mine flash, but ever so slowly, so I found these controllers which need a separate ground, but are supposed to work with LEDs, and the price seemed more reasonable than trying to find resistors to put in parallel with my lights(since Radio Shack disappeared).

My problem is, that I looked at the Maintenance manual electrical diagrams, and can't find any indication of it on any of the panels.
It seems like it would be in the panel by the driver's seat, but the diagram does not call it out.  The Voltage regulator is located on the first bay wall, but that diagram doesn't show a flasher unit either.  And before it is asked, No, I did not pull the cover yet and look for the "round thingy like in my car" yet.  I think it was about 95 degrees plus inside the bus, so I was on a generous work-rest cycle so as to avoid heat exhaustion.

All help is greatly appreciated!

Steve Toomey

[chessie4905]

The flasher relay is in center of dash on front side. If you still have that panel on front right, open it. It is towards the center. It is bigger than the round ones.

[pabusnut]

Thanks John,

I don't know why 'Da Book' didn't make a reference to it.  Maybe I just didn't search for the right term.

Steve

[pabusnut]

Still having trouble with turn signals.  They blink, but VERRRRRRY SLOOOWWWWLLLY.
I don't see anything that even vaguely resembles a flasher unit anywhere under the dash.  If any 4905 guys out there could take a picture , I would greatly appreciate it!

I have tried putting another 24VDC bulb in series with my LED turn signal, but even that doesn't seem to help, and it doesnt blink, so I think I have a different problem.  Maybe my flasher unit is toast!

Is there an aftermarket 24 VDC electronic unit which I could use to replace this partially working one with?

I had planned on leaving Tuesday for Blytheville, but not sure if I want to risk having partially working turn signals.

Any help is greatly appreciated!


Steve Toomey

[richard5933]

If my memory is correct, the flasher unit on these is located inside the compartment to the right of the defroster core at the nose of the bus. This is the compartment at the nose of the bus, accessed from inside the bus over the stairs.

There will be two flashers in there - one of them is the flasher for the "Watch Steps" light on the ceiling over the aisle, and the other works the turn signal flashers.

Double check all your bulbs in your turn signal system. If one of them is blown or has a bad connection/ground the entire system goes wonky. There are six lights in the turn signal system - two front, two rear, and one on each side.

[chessie4905]

Remove the led's and reinstall regular bulbs. If the flasher now works properly, it'll save the cost of a new flasher. If the flasher is actually bad, contact Luke.
Here is one of several 24 volt 24 volt led flashers available.

https://www.amazon.com/HELLA-009492001-24V-Flasher-Unit/dp/B003C4WDHY

[richard5933]

Remove the led's and reinstall regular bulbs. If the flasher now works properly, it'll save the cost of a new flasher. If the flasher is actually bad, contact Luke.
Here is one of several 24 volt 24 volt led flashers available.

https://www.amazon.com/HELLA-009492001-24V-Flasher-Unit/dp/B003C4WDHY

What he said. Didn't notice that you were running LEDs in the turn signals. The system is really fussy about having the correct bulbs in place.

[freds]

Remove the led's and reinstall regular bulbs. If the flasher now works properly, it'll save the cost of a new flasher. If the flasher is actually bad, contact Luke.
Here is one of several 24 volt 24 volt led flashers available.

https://www.amazon.com/HELLA-009492001-24V-Flasher-Unit/dp/B003C4WDHY

Wow this is just the thread I was looking for!!! I figured there might be a problem switching over.

chessie4905: Have you used this flasher?

[chessie4905]

No, because I havent changed to leds.....yet🤔

[pabusnut]

OK-- Problem is fixed!!! Woo Hoo!!!  Yipee!  I can go to the Blytheville Bus Rally!!

To solve the resistence problem, I wired regular old incandescent bulbs in parallel with the LED's and I thought that fixed it( sort of Redneck, but it will do until I can buy the right resistor) It worked perfectly, but then the next time I turned on the signals(either left or right) they wouldn't blink or stayed on forever, but it wasn't consistent.

So I started checking and cleaning grounds.  Yes, I cleaned all of them except for the little side ones, and still no change.
I remembered a post where somebody's turn signal switch at the steering wheel went bad, so I started there next. 
When I got the connector apart under the dash, I immediately noticed what might be a problem.  One of the pins was pushed out of the connector.  I continued to check with my meter to see that the switch was working correctly. 

Once I "fixed" that pin so it stays in the housing, I put it back together and crossed my fingers! 
Turned the power back on and turned on the right blinker and like magic, it blinks perfectly!  The left too, and the 4 ways!!

I have had trouble with the turn signals since I owned it, although they never worked as bad as when I added the LEDs.  That connector must not have been seated right all these years.

I do still need to find where the relay physically resides, so I can get a spare, but for now all is well!

Steve Toomey

[chessie4905]

The relay is right behind the center dash panel. Open the dash panel door right by the entrance door steps. There are two flasher relays. A common sized one and a larger one about 1 1/2x2 1/2 x4". The larger one is for turn signals and 4 ways and the other one is for the flashing step sign if yours is still there/ working. The large relay is bolted to the channel.

[chessie4905]

Here

[chessie4905]

Here

[chessie4905]

Here

[chessie4905]

Here