552 Flasher goes too quick

[Rob M.]

I have a used (non dot orig type) 552 flasher in my non-backup light 65. It flashes too quickly. Anyway to "adjust" this to be slower? I am hoping there is a trick to save this nice orig flasher. The system work fine with a replacement 552 flasher from the auto parts store.
Thanks

[Joe R.]

Re: 552 Flasher goes too quick

Have you double-checked to make sure that you have the right bulbs in the lights that are being flashed? This should be confirmed before you consider making any modifications to the flasher itself. If the bulbs are higher output than the originally specified bulbs, they will draw too much current and make the flasher cycle too quickly.

If you confirm that the flasher itself is the problem, it is theoretically possible to open it up and replace the "guts" with the guts from a replacement flasher. That way you can keep the original case but you get new internals.

If your flasher is like a 67 552 that I have on hand, it has an aluminum case with the edge formed around a bakelite base that holds the flasher mechanism. Chances are that the bakelite base of the replacement flasher is the exact same size as the original, so a swap may be possible.

I have performed such a swap on the plastic 323 turn signal flasher that my 67 uses, and it was pretty easy to do. If you have an aluminum housing the job will be harder, but not impossible.

I would suggest that you sacrifice the original bakelite base by drilling a few holes in it and then carefully breaking it into pieces to remove it. This will help preserve the edge of the aluminum case that you are trying to reuse. If you are careful and patient, I think that a guts transplant can be accomplished even with an aluminum case.

[Peter L.]

Re: 552 Flasher for 65 Corvette

Rob - While it appears that the 552 flasher you have has a problem, probably some corrosion on the interal bimetallic piece, the 552 is a variable load flasher for 2 to 8 lamps and is not the type of flasher used originally in the turn signal system on the 65 Corvette or in fact any GM vechile. As far as I know, all turn signal systems used fixed load flashers, e.g. a 2-lamp flasher for vehicles equipped with 2 lamps(1 front and 1 rear) or in your case a 3-lamp flasher for vechiles equipped with 3 lamps (1front and 2 rear). The use of the fixed load flasher in the turn signal circuit is a safety item because if a lamp burns out the turn signal will not work but with a variable load flasher the system will still operation so if a bulb burns out, the problem will not be noted because the good bulb will be flashing.

So in spite of what the 65 TIM&JG might say the 552 is not the original type of flasher used in the 65 Corvette application and the appropriate Tung-Sol flasher would be a 323 and for 65 I would expect a yellow painted metal cover 323. I believe the Signal-Stat flasher listed in the 65 TIM&JG is correct, being the Signal-Stat 145 and I would expect that to have the yellow anodized rectangular cover with 145 embossed on the top of the cover.

Pete

[Rob M.]

Re: 552 Flasher for 65 Corvette

Peter, thanks for the information and the explanation. I have 323 that is as you described and was trying to get the 552 to work based on the TIM&G. I will go with your advice.
Thanks again
Rob

[Paul L.]

Re: 552 Flasher for 65 Corvette

Pete,
I believe the 1967 uses two flashers. One is 323 for the signal lights (on radio panel left on clip) and 552 for four-way flashers (on fusebox). Is that correct?

[Jack H.]

Re: 552 Flasher for 65 Corvette

Current JG book calls out non-DOT flashers:

Tung Sol 323 (yellow plastic can) or Signal Stat 145 for the TS flasher.

Tung Sol 552 (natural finish can) or Signal Stat 170 (gold finish can) or Signal Stat 175 (green finish can) for the 4-way flasher.

[Peter L.]

Re: 67 Corv Flashers:Turn Signal & Hazard-Warning

Paul - Yes, as Jack has pointed out those two Tung-Sol flashers, the Tung-Sol 323 and 552 are appropriate for 67 and as also noted GM also used flasher manufactured by Signal-Stat that are also appropriate, specifically the Signal-Stat 145 and the 175 for the corresponding applications. I would suggest that the Signal-Stat 170 was not typically used in the 1967 Corvette hazard warning lamp circuit because the 67 Corv has a 6-lamp hazard warning lamp system and while the Signal-Stat 170 is listed as being designed for 2-6 lamp systems, it is typically used in the hazard warning lamp system with 4 lamps (2 front & 2 rear lamps) like the 66 Corvette with V74 and 67 Camaros, Chevelles, Chevy IIs, and Corvairs that had 4-lamp systems while the Signal-Stat 175 is listed for 2-8 lamps and while there is overlap, typically what I have observed is the 170 was used with the 4-lamp hazard warning systems and the 175 was used with the 6-lamp hazard warning systems.

It's interesting to note that the 66 Corvette AIM calls out FLASHER ASM P/N 3843741 for the V74 Traffic Hazard Lamp Switch & Harness Assembly and original V74 systems I have seen have the gold, embossed top 170 Signal-Stat flasher; while the 67 Corvette AIM calls out P/Ns 1381303 and 3883794 (OPT) FLASHER ASMs for the hazard system flashers in the FUSE PANEL. Typically the 67 FUSE PANEL flashers are the Tung-Sol 552 or the Signal-Stat 175. I have several GM "blue & white" boxed SERVICE PART, P/N 3883794, and they contain the Signal-Stat 175.

I did not find a SERVICE P/N listing for P/N 3843741 that I am assuming is the Signal-Stat 170 but the P/N, P/N 3843741, is not called out in the 67 AIM as one of the flashers used in the 67 hazard lamp circuit . Perhaps Joe Lucia can come up with some additional information on the flashers associated with the production call out P/Ns.

Pete