Testarossa light bulbs?

[gjpearce]

The local auto parts store no longer stocks the taillight bulbs. Where can I get them?

[302Tim]

Seems like a simple question...

Please fill out your profile so we know what country you are in--that would help tremendously with knowing what configuration your lamps are as well as available resources.

Italian terminology does not include "taillamp" so I suspect you mean the two outboard lamps on the bottom row, which on a USA TR are referred to (rather ambiguously) as "parking and stop lights". In reality, both illuminate as "taillamps" when the lighting switch is in position 1 or 2, but the middle one also acts as a second stop lamp so it is a dual-filament bulb, and the farthest outboard lamp alternatively illuminates when the "park" button on the center console is depressed (with the lighting switch "off") and is a single-filament bulb. For reference, the farthest inboard lamp is (solely) a stop lamp (single filament) in the USA but I noticed in the Euro OM this is identified as a rear "fog" lamp.

So if a USA model I think you need SAE type 1073 for the farthest outboard (and inboard) lamps and a dual-filament SAE type 1034 bulb for the middle. If yours is Euro it may be the same bulb config, I'm just not sure (nor do I know if they use SAE standards).

For sourcing, all the USA parts stores I have been in still carry both of these bulbs in large numbers but if you can't locate, do a web search for "Sylvania 1073" or 1034 and you will find countless sources. Philips is another common bulb manufacturer. In the meantime you may still have a spare in your spare bulb holder in your jack bag.

Also, you could switch to LED bulbs, do a search in this forum for James Baldwins conversion, he lists sources and part numbers.

[Melvok]

Do you mean these normal all-car bulbs ??

[gjpearce]

i am just a little confused- the listing all say I need 1073 taillight bulbs- i removed my tailight bulb and it has imprinted on it- 12V 5W. All the 1073 bulbs I can find have much higher wattage ratings- does it matter if it draws more amperage-am I going to bloe fuses- i simply cannot find a 5 watt bulb- what do you advise?

Originally Posted by Melvok

Do you mean these normal all-car bulbs ??

[Red Head Seeker]

Check the cross-reference chart Thread....lots of bulb info.....Mark

[KENCO]

I had the same thing happen to me on another car. Bulb was discontinued. I replaced it with and identical looking one, meaning, same base and one or two filaments.........I cant remember.

It worked fine, but it was on a third brake light so it is not on all the time.

Just found this site, they got the 1073's for $1.00 each or 10 for $5.00

http://www.replacementlightbulbs.com/lamp1073.html

[Steve Magnusson]

The outermost bulb on each side in the bottom (red) row should be 5W on a late US version TR. It serves as a running light and the true "parking" light (the one that comes "on" when the "P" button is pressed). If you use the higher wattage 1073 in that position it will be wrongly bright (compared to the 5W running light filament in the 1034 bulb) and dissipate more power when used for the "P" function.

Try a search on "R5W bulb 12V", or "R5W bulb cross reference" -- e.g.:

http://www.imperialsupplies.com/item/0819143

To drill down on a bulb suppliers page, look for:

Incandesant/General
Voltage = 12V
Power = 5 watts
Base = ba15s (bayonet, 15 mm diameter, single contact)

The inboard, single-filament bulb in the red row should be the 21W 1073 for the same reason -- to match the 21W brake light filament in the 1034 bulb.

Not sure if versions/years vary (and I've noted that even the 509/88 schematic is a little messed up in this area), but bottom line is that any filament that is a parking/running light should be 5W and any filament that is a brake light (excluding the CHMSL) should be 21W.

[KENCO]

Steve,

Would that be the only issue, it would light brighter? Would it blow fuses? I would say for me the brighter the better. It seems all newer cars have such brighter lighting than all my 70-80's cars do.

[Steve Magnusson]

Originally Posted by KENCO

...Would that be the only issue, it would light brighter? Would it blow fuses? ...

No, it probably wouldn't blow the fuse, but it does push the current up to about the maximum allowable for the size of the fuse (and one never knows if there is any margin in the size of the traces used on the PCB ). The 5W bulbs draw ~0.4A, and the 21W bulbs draw ~1.8A so, if you only use the higher power bulbs at the rear, the total current in fuse #15 (7.5A rating) would be (0.4 + 0.4 + 1.8 + 1.8) = 4.4A. Not great, but not catastrophe.

I've never felt a need to use the "P" function (as we don't have the same "narrow streets" issue as the guys in Europe), but that might be more trouble as drawing 4.4A (vs 1.6A) overnight (say for 12 hours) would be a significant (and probably unacceptable) drain on the battery's total A-h capacity.

The final thing that you might check if you do use the 21W bulbs in those positions is if the red plastic housing gets warm/soft after lengthy use. The brake lights are also 21W, so I'd guess that things would be OK, but the designers may have relied on the fact that it would be very unlikely to have the brake lights "on" for several hours.

Since we haven't had any reports of trouble here (and some people probably have used the 1073 in those positions), my bottom-line guess would be = OKish (as long as you don't use the "P" function for more than a couple of hours)...

[KENCO]

Agree,

Most likely no one has used there parking lights since 1969 in there VW bug in San Francisco!

[jrbaldwin]

You might want to check your white fuse box connections before increasing the draw. I found one of my tail light white connections was burnt. The connections was loose or corroded causing heat. I upgraded my fuse box, cleaned and tightened all the connections so they make better contact and did a LED upgrade to lower the draw thru the fuse box.

Jim