Hella blinker/emergency light relais TBB26

[fourteenten]

Probably not many around of those but can only try to find a replacement Hella TBB26 relais to replace the faulty in my 73. If someone has a spare I can try to confirm mine is bad that would help big time.

Regards,

Cees

[911GP]

Hi Steve and Cees,
This is an interesting thread since I went through some trial and error when restoring my car. As Steve points out, later 73 (and maybe 72?) cars had a feature where the handbrake light flashed when it was pulled. Not all 4 pin relays can provide this feature (especially new ones, like Werhle and new Porsche ones). Through some trial and error I found the Hella TBB4 4DB003425 worked fine and had case markings of 2(4) x 21w +0 and I think the +0 bit related to the handbrake which draws 0 watts.

A couple of questions for you each please:

Steve - your RS is older and you have owned it forever. What relay do you have (model and markings) and does your handbrake light flash when the handle is pulled?

Cees - your RS is a 73 model year so I think the handbrake light should flash when it is pulled. Did this happen with the relay you have and is the relay original to your car? I notice that the model you have is TBB 26 DB4002479-01, which matches Steve's Hella booklet, but it doesn't state +0 on the casing.

Thanks
Gitesh

[fourteenten]

Hi Steve and Gitesh,

Yes, it is the one in my 5.73 RS and handbrake light flashes when handbrake is pulled. Just bought a new Porsche (914 part number) relais just to see if the relay is really faulty.
Some background might be useful to explain why I would like to try another original relay; My RS did have an emergency flasher mounted (SAE68 version) and being an Italy delivered car it is clear that the PO mounted it later. The flasher worked fine, lighting up the indicator lights in the gauge when pulled. Tried the SAE72 version flasher because of the correct year. It did work somehow but the indicator lights in the gauge would not flash anymore when pulled (lights flash ok in the indicator units). Found out that in 72/3 with the SAE72 flasher also a different wire loom was added with an extra ground wire. Went back to the first flasher but still no indicator lights flashing. Not a big deal but when I start the car the relay keeps ticking about every 2 seconds and not as loud when I pull the emergency flasher.

Third option was to leave the emergency flasher out and have the single wire connector as used in the Italian version. Tried that but then I have no indicator lights at all...weird stuff.

Regards,
Cees

[McOtto]

I’m guessing the Hella TBB3 mentioned in the attached thread may be unique to US Spec cars and US DOT requirements, but thought I would add this link in case it is of any help.

https://www.early911sregistry.org/fo...1-Flasher-Unit

[fourteenten]

Hi Steve,

Yeah, the handbrake light did flash when pulled and ill check if it still does work after all my fiddling with flashers and relays. I have tried a cheap Amazon one and that one did the opposite; flash on (light switch blinking it was off and vice versa, flasher off it would flash..). I know that PO did some weird stuff with the wiring and plan is to get that sorted. Major operation, taking out the front wire loom, remove 3 (!) small switches that either cut the power or ignition or fuel pump, all hidden away. First of all is to get rid of the annoying clicking sound of the relay before we drive to Goodwood!

Cees

[911GP]

Thanks Steve. I love to hear stories like this. My DVLA records show the previous owners too but I have only been able to make contact with the previous owner and the “first” owner. As it turns out, the first owner on the DVLA records wasn’t the actual first so it looks like the DVLA don’t have all the history available.

[fourteenten]

Update, just mounted this new relay. Interesting, the handbrake B sign blinks plus both green indicators in the rpm gauge. The emergency flasher does not work with this one (not to worried about because I rather remove it completely) but no more clicking sound at least.
Funny things these relays..


Cees

[fourteenten]

Wow, that is a pretty impressive collection, now we now where they all went
If you could bring one to Goodwood for me to try out, that would be fantastic.

Regards,
Cees

[fourteenten]

Was looking at the 72-89 service manual with the electric diagrams and in both 72 and 73 diagrams can't find that relay anywhere. Actually, Porsche calls it transmitter in the PET catalog and not relay. Part number in 72/73 is PET 914.618.302.11, current version (not Hella I reckon) 914.618.303.12. Am I missing something here?

BTW, I am not 100% sure that the hand brake symbol blinking in the combi gauge has anything to do with the emergency/indicator relay/tramsmitter. In the wire diagram I do not see a connetion to any relay or it must be to the relay which is not pictured.

Regards,
Cees

[McOtto]

BTW, I am not 100% sure that the hand brake symbol blinking in the combi gauge has anything to do with the emergency/indicator relay/tramsmitter. In the wire diagram I do not see a connection to any relay or it must be to the relay which is not pictured.

I could be misreading your statement, but the wiring diagram for my ‘72 shows how the blinker relay is connected to the handbrake light (see off page connector number 40).
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