WOT switch

[Porsche 935]

Has anyone ever ohmed out their WOT switch on their Carrera? Mine shows continuity at or above 3/4 throttle but the ohm reading are all over the place. I don't think that's right.

[Porsche 935]

Anyone willing to do an ohms test on there's with the plug removed and share your readings?

[dtxscott]

It's a mechanical switch with contact points. The resistance reading should be effectively "zero" at that point. You might see a few milli-ohms on a meter or some bouncing as the contacts settle.

What reading are you getting at WoT?

[cabmandone]

Originally Posted by Porsche 935

Anyone willing to do an ohms test on there's with the plug removed and share your readings?

I'll try to remember to test mine when I'm out in the shop tomorrow.

[mysocal911]

Originally Posted by dtxscott

It's a mechanical switch with contact points. The resistance reading should be effectively "zero" at that point. You might see a few milli-ohms on a meter or some bouncing as the contacts settle.

What reading are you getting at WoT?

Doesn't get any simpler than that!

[Porsche 935]

That's what I assumed but my readings are all over the place. 400-5000 ohm's of resistence. Just wanted to make sure before buying a new one.

[Porsche 935]

Anyone willing to ohm there's?

[wazzz]

Have done it a few years ago and as mentioned above, it is either on or off. Can't remember if it is open or closed at WOT, but whatever, the state changes from 0 ohm to infinity or from infinity to 0 ohm at about 2/3rd of throttle range. Your switch is toast or you are not using your DMM properly. What is it reading when your short the cords and what is it reading when not connecting the cords?

[Porsche 935]

Thanks. I will order a new one. Just wanted to make sure it was a switch type. I have been a mechanic for 30 years, so definately know how to use my Fluke meter.

[Porsche 935]

I fixed the contact points in my switch, it ohms out good but when switch engages car falls on its face. Not sure if switch is shorting out or what. None seem to be available. Mine has part # 0 280 120 309. Anyone know the difference between mine and part # 0 280 120 308?

[Porsche 935]

Bump

[NotStock]

I installed the one from Pelican, 911-606-013-03

I believe Pelican listing calls out alternative part numbers. Worked great on my '84.

[Porsche 935]

How long ago? I called them to purchase one and they had none in stock and no shipment dates anticipated.

[cabmandone]

To be clear, we were discussing the switch on the right hand side of the throttle body, the one that you can rotate slightly, correct? The part number for that is 944-606-113-01
The switch above at comment number 12 is on the left side and senses when the throttle opens off idle.

[boyt911sc]

Originally Posted by Porsche 935

Thanks. I will order a new one. Just wanted to make sure it was a switch type. I have been a mechanic for 30 years, so definately know how to use my Fluke meter.

Post a picture of the switch your are troubleshooting. Most people don’t remember the parts # and probably get a better response to your inquiry.

Tony

[NotStock]

Sorry, I'm off base, I'm thinking idle switch. Disregard.

[Porsche 935]

Need to know the difference between the two switches if there is one because when I called pelican about purchasing a new one they indicated it having a sweep arm and computer chip inside but mine only has a set of points.

[911obgyn]

My 85 carrera has a switch that closes at idle opens during part throttle and closes again at WOT.

[E Sully]

The part that contains a sweep arm is the air flow sensor. Then there is an idle switch for the idle air control valve which is just a set of contacts, then a wide open throttle switch that also just a set of contacts that bypasses the usual mixture program in the chip to give a richer mixture. The wide open throttle switch also bypasses the O2 sensor and shuts off the A/C compressor. The idle and wide open throttle switches should just read continuity when closed.

[Porsche 935]

So, I guess the different part numbers for the wot switch may just be an update or minor change based on production and year built. Mine works well now based on ohm tests, just when it switches to the WOT map it seems to not switch back based on fuel mixtures I see on my wideband o2 sensor. I imagine there could be an issue with the dme based on some information I have received.