Top Switch of TCVAS

[Sierra]

Hey guys, I need some help finding the Top switch for my Honey Bee.

 

The Top Switch is part of the Transmission Controlled Vacuum Advance System (TCVAS) that disables the advance except in Top Gears.

 

I can’t find it anywhere

The part number is: 32006-H6500

I found the reverse Lamp switch (RockAuto)

Anyone knows if they are interchangeable?

[datzenmike]

Reverse, neutral and top (4th) gear switches are all different numbers. The thread may be the same but the switch may be OFF in 4th not ON like the reverse lamps switch.

 

32006-H6500 is unique to the B-210

[ggzilla]

 

Hey guys, I need some help finding the Top switch for my Honey Bee.

It's right here:

 

 

They differ

 

Get it from Nissan. Ask for the Nissan part number, not Datsun

[ggzilla]

32006-H6500 for early Honeybee

32006-K2000 for 1977 Honeybee

 

http://www.courtesyparts.com/switch-4th-p-339909.html

[Sierra]

Thank again for all the info.

I will try my local Nissan dealership and see if they can find it for me.

I the past I had no such luck.

that courtesyparts.com has been a pain too, b/c the website will mark the item in their inventory but once you complete the transaction you get an email letting you known that the item is no longer available.

Will see.

Thanks again.

[ggzilla]

That is the Nissan USA parts system, it is not unique to Courtesy Nissan. I was told they keep items in the catalog for 10 years after becoming NLA before removing it.

 

Seriously messed up.

[ggzilla]

By the way, the TCVAS system will work perfectly (reducing emissions) if you connect the two wires together at the transmission. The only downside is the advance won't work in top gear, but it will run well even so. Fuel economy won't be perfect in top gear but will run good.

[ggzilla]

If the wire has broken off the switch, get an electronics friend to solder it back on. Easy fix.

 

When you take the switch off, let us know which of the two in the photo it is.

[Sierra]

Thanks ggzilla! :thumbup:

What am I trying to accomplish is better fuel economy, so some fine tuning to my B210 is in place.

With that said, I would like to see the advance work on 4th gear.

So my Top Switch is a must :geek:

[ggzilla]

If you leave the Top Switch unconnected, you'll get better fuel economy, as the full advance will work in all gears. For maximum economy, connect distributor to manifold vacuum like the MPG engine does.

[Sierra]

I did not know that. Thanks again ggzilla.I just might then disconnect the Top Switch and see how it runs.

 

Can you explain more about the MPG engine setup?

So do I "T" the Vacuum advance? One end to the Distributor Vacuum Advance Diaphragm and on the other end 1) The Distributor Advance Port on the Carburetor and 2) The other to a direct port to the manifold?

 

Or Vacuum advance diaphragm to manifold and capping the Distributor Advance Port on the Carburetor?

[ggzilla]

If your Top Switch is bad, then TCVAS is not working. Its not retarding the spark.

 

You need do nothing to disable TCVAS except unplug the Top Switch. Leave it in the transmission so the gear lube doesn't leak out. Later when you get a good switch you can plug it back in.

[ggzilla]

Can you explain more about the MPG engine setup?

So do I "T" the Vacuum advance? One end to the Distributor Vacuum Advance Diaphragm and on the other end 1) The Distributor Advance Port on the Carburetor and 2) The other to a direct port to the manifold?

 

Or Vacuum advance diaphragm to manifold and capping the Distributor Advance Port on the Carburetor?

Yes, the latter. Then set the idle speed as it will go up, so set it back to 700 rpm.

 

But first make sure the Advance can on the distributor is working. I have found about 90% of them are leaking vacuum now after 30+ years.

[Sierra]

Suprise, suprise!


 

 

On a good note the Vacuum Advance Diaphragm I order from RockAuto has been shipped B)