Tail Lights C2 65

[Mike M.]

Can someone tell me if there is a difference between a 1034 tail lamp and a 1157
tail lamp. They both work but 65 calls for a 1157. I seem to remember something about the flashing of the blinker lights being to slow or fast if you have the wrong type in.
Mike

[John H.]

Re: Tail Lights C2 65

Mike -

My '57 owner's manual calls out #1034's at 32 candlepower, and my '67 owner's manual calls out #1157's also at 32 candlepower, which makes no sense, as I have always been told that 1157's are "brighter" and draw more current, which would affect the flashing rate. Maybe someone else can quantify the difference.

[Mike McKown]

the way I remember it,

1034 bulbs were used on front park lights with clear lens through 1962. Starting in '63 an amber lens was used (I think some kind of Federal Standard) and required a brighter bulb to get suffcient light through the amber lens. Hence, the 1157.

[Michael H.]

Re: the way I remember it,

Pretty close Mike. Actually, it was a change for SOP of the 64 model year that affected all Chevrolet car lines. (probably all GM lines) The 1034 bulb used for 1963 was replace by the 1157 in all new 1964 vehicles. It not only changed the parking/tail lamps but also included the headlamps and, supposedly, all the rest of the lamps in the vehicle.

If I remember correctly, the difference was the wire diameter of the filaments, which would require more amperage to operate at the same brilliance. That also required a different flasher unit to compensate for the additional draw from the lamps. The results were longer lasting lamps.

Michael

[Mike McKown]

Re: the way I remember it,

Seein' as how you are as sharp on this stuff as you are, I don't doubt you one bit. I just have this nagging suspicion you are one year off. Can't document it. I just think it.

For anyone interested, there was a 1034, 1157, 1034A and 1157A. The "A" suffix meant it was an amber colored bulb. Otherwise the same as the base number.

[Michael H.]

Holiday Inn Express

Mike,

I really don't know anything about this but..... I DID stay at a Holiday Inn Express last night!

Ok, real story is, the entire electrical system was completely redesigned for the 64 model year. This included just about everything in the system. In addition to all the lamps, the wiring harnesses were all new for 64, to handle the increased current load. There was even a note that warned against using the new 64 lamps in the 1963 system because the wiring wasn't designed for the increased load. The turn signal flasher was a different part number and load range for SOP of 64 and there was a new part number for headlamp bulbs also.

I'll try to find and post the GM paperwork on this.

[Scott S.]

Re: Holiday Inn Express Taillights

The note on my "new" TLD lights says "For use in models prior to 1964, replacement withbulb no. 1034 may be required to produce acceptable flashing rate". My 65 always used the 1157's as far as I know

[Mike McKown]

I'd betcha' this is new info to a lot of people.

I've done some digging since my first post and it appears you are on target, as usual! My brain has failed me once again.

[Steve D.]

Re: Holiday Inn Express

I'm considering replacing all of the harnesses in my 63. Would the 64 harnesses be considered an upgrade, or ill-advised because of too many differences to adapt?

Steve

[Michael H.]

Re: I'd betcha' this is new info to a lot of peopl

Mike,

Finally found some GM paperwork on the "new electrical system" for the 64 model year. (I knew it was here somewhere in all this rubble) Pretty interesting stuff, some of which I had forgotten over the years. I can post if anyone is interested. It explains why the lamps, wire harnesses and several other items were new for 1964.

[Michael H.]

Replace Harnesses

Steve,

Using 64 wiring harnesses in your 63 is possible but it definitely wouldn't be a "plug and play" installation for all of the connectors. I think the 64 forward lamp harness is the only one that is the same as 63, as far as installation. The other under hood harness that feeds the alternator/reg etc would have a different connector for the heater blower motor. The under dash harness would have a different style connector for the ignition switch and possibly other items that I can't think of. In addition, several of the wire colors and sizes changed for 64 so if you are trying to maintain originality, I would consider the correct 63 reproductions. I've heard the reproduction harnesses are accurate but I've never used one so I don't know for sure. Maybe others can advise on a source.

[Duke W.]

Re: I'd betcha' this is new info to a lot of peopl

Yes, post! I would also be a good article for The Corvette Restorer.

Duke

[Michael H.]

Document From Engineering

(typed exactly as released from engineering)

HEADLAMPS AND BULBS

"All headlamps and bulbs used for any location in all 1964 Chevrolet vehicles will be of a new heavy filament type for increased durability. Each bulb unit will be identified with the standard trade number stamped on the base. For the service replacement of any bulb used on a 1964 vehicle, care must be exercised to select the proper rated bulb for this purpose. If a similar bulb for a previous model were included in a 1964 system, no major damage would occur but there would be a definite difference in lighting brilliance offered by these bulbs. The use of 1964 bulbs on previous models is not recommended due to the increased amperage required for these units. 1964 electrical systems are calibrated and revised specifically to meet these requirements".

"NOTE: No attempt should be made to change any bulb or bulbs, or the flasher assembly between the 1964 and previous design turn signals. Here, not only will a difference in lighting intensity be noted but also a change in flasher speed".

[Mike M.]

Re: Document From Engineering

Michael, I had it backwards, thought you could use 1157 in pre 64 and not use 1034 in later years. The 1034 just won't be as bright if used in 64 and later.
Thanks for the information, Mike

[Timothy B.]

Re: Document From Engineering

On my 63 I installed the 1157 bulbs that came with the GM front and rear lights. The original 143 signal stat flasher was also used and the flasher speed was faster than normal. After I discovered the 63 called for part #1034 bulbs I installed them and there is a noticable difference with flasher speed to what I would consider normal operation.