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Posted by: lmcchesney Aug 6 2004, 08:49 AM

I replaced the oil pressure sender on the top of my case with a sender which provides light activation and VDO oil pressure reading. How do I know which pole is for the light and which is for the pressure gauge?
The gauge also has three connectors for the gauge (not the connector for the light) which is marked +, G and grnd. What connects to what?
Thanks,
L. McC

Posted by: ArtechnikA Aug 6 2004, 09:08 AM

do the poles on the sender have ANY markings ?

+ - switched (Terminal 15) +12VDC
G - Gauge
grnd - ground

Posted by: lmcchesney Aug 6 2004, 09:14 AM

Thanks,
The poles of the sender is marked G and Mk.
L. McC

Posted by: ArtechnikA Aug 6 2004, 09:19 AM

Mk is going to take some thinking - but by convention G is always gage, and by process of elimination ...

you can also test this with an ohmmeter. you'll have continuity (real darn close to 0 ohms) between the Mk and the case if that's the light; G and the case should give you measurable resistance.

Posted by: synthesisdv Aug 6 2004, 09:29 AM

I have the same dual sender.

How can I be sure it will work with this gauge?

dr


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Posted by: ArtechnikA Aug 6 2004, 09:38 AM

wire them up in your kitchen and dunk the sender into boiling water.
or c-a-r-e-f-u-l-l-y heat a small container of oil and calibrate with a deepfry/candy thermometer.

to be SURE you send the gage and the sender off to Palo Alto Speedo and get everything matched and calibrated.

Posted by: Demick Aug 6 2004, 09:40 AM

Hey Rich - does that mean that I can check my tire pressure with a thermometer? Sorry couldn't resist

Posted by: ArtechnikA Aug 6 2004, 09:45 AM

actually - that's a good point, because if L is running an idiot light and pressure gage from his double-pole sender, it obviously CANNOT be the same double sender dv is using. (if it actually *is* the same double sender, one of them is not going to get 'the desired results' ...

(for your problem, get a BIG vat of 350-degree oil. put in your tire. you will have no further problems with air pressure :-) ...)

Posted by: synthesisdv Aug 6 2004, 09:46 AM

I think we are talking about the dual oil "pressure" gauge. Don't think that should go in boiling water, no?

dr

Posted by: gklinger Aug 6 2004, 09:46 AM

Check this out: http://www.vdona.com/Tech%20Support/Automotive/instructionsheetspdffiles/0%20515%20012%20123%20--%20Electric%20Gauges.pdf

Posted by: ArtechnikA Aug 6 2004, 09:50 AM

you are correct...

but accurate air pressure gauges are not too hard to come by, so if it's pressure we're talking about, there you go.

Posted by: rdauenhauer Aug 6 2004, 04:47 PM

How about a pic of this sender and where is it being procured?

Posted by: Mike D. Aug 6 2004, 05:20 PM

I'm working on this right now, been out in the garage last two hours with this and 911 tach. I started a similar thread last night...

I just hooked up the 911 pressure gauge when turn the power on the gauge comes up to zero then when I start the engine it pegs the top. That can't be right, can it? I unplugged the ground and it stayed pegged at the top let the engine die and it drops to zero.

what's wrong here? guess I should make a trip to No. Hollywood Speedo too.

-Mike D.

Posted by: synthesisdv Aug 6 2004, 05:24 PM

this bugger,

have to remote mount becuase it won't fit down in the tin.

any 914 friendly place like pelican or aircooled.net has it.

dr


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Posted by: ArtechnikA Aug 8 2004, 07:58 AM

verify your connections, of course. the ground may be provided (more or less well) by another connection.

early 911's had 150-psi oil pressure gauges, the downside of which is that everything under about 15 psi looks like zero, which many considered alarming. (it's a 911, get used to zero oil pressure at idle :-) ...) anyway - mid-80's somewhere they yeilded to the complaints and in typical fashion, simply doubled the sensitivity of the gauge making it a 0->75 psi gauge, with more room to spread out the lower numbers.

the gauge must match the sender ... i don't think any Porsche gauges match any aftermarket VDO senders ...

Posted by: lmcchesney Aug 8 2004, 10:44 AM

Thanks everyone,
Gerry, that link was very helpful.
One thing I picked up was the comment about using teflon tape on the sender may prevent the sender from achiving a ground.
L. McC

Posted by: Walter Aug 16 2004, 02:15 AM

Well, actually, the G stands for 'Geber'. 'Geben' is German for 'to give', so it is the pole that gives the information...but ' Gauge' will be fine as well

Just teflon tape it for sealing and groud the sender to something else.

Anybody did this similar?

Greetings,
Walter

Posted by: Cap'n Krusty Aug 16 2004, 08:52 AM

That brake hose may have 10 x 1mm threads, but they're straight threads, and the case has tapered threads. I use a grease gun hose, which has tapered threads (and it's cheap!)
The Cap'n

Posted by: John Kelly Aug 20 2004, 01:49 PM

Hmmm...so can the two terminal sender be used for only the idiot light by connecting only to the terminal not marked G? My engine has one of these, but the car only has an idiot light, no gauge.

Thanks, John www.ghiaspecialties.com

Posted by: Demick Aug 20 2004, 02:36 PM

Yep.

Posted by: Demick Aug 20 2004, 02:42 PM

On 914's, since you can't mount the sender directly (doesn't fit with the engine tin), you must mount it remotely using a flexible hose as was discussed here. So you cannot achieve a ground connection through the threads anyway (electricity doesn't really like to travel through 12" of rubber hose). You must make sure the body of the sender is grounded - usually through it's mounting bracket.

Demick

Posted by: DrifterJay Aug 20 2004, 11:45 PM

my engine tin is trimmed...fits nicely..

Posted by: ArtechnikA Aug 21 2004, 06:56 AM

'course what you've done is mount a big heavy pendulum onto an aluminum boss in a high-vibration area. these have been known to fail when the stress work-hardens the aluminum as it eventually will. but it's nothing a new case won't fix ...

there's a reason most people remote mount those...