914-SHO Gauges for vitals?

[3d914]

OK, I need to start thinking about how I'm going to monitor a few things I don't have gauges for in the 914. I've already addressed the Tach - at least for the bench test. Since I'm won't be using coolant fans, I'll rig two lights for the fans to indicate if they're switch on.

Gauges: (Am I missing something?)
How are each of these handled for stock SHO?

• Coolant Temperature, ON/Off, light on dash
• Oil Pressure - On/Off, light on dash

Also have some related questions on wiring.
I'm seeing references to the ECT (Engine Coolant Temp Sensor) which I've verified is the LG/RD wire, and the Coolant Temp Sender - RD/WT wire. The sender doesn't show up on any of the PCM schematics.

On the 3.0 PCM, VSS (-), an OR/Y wire, appears to also serve a grounding function for the PCM - is this correct? Can someone verify?

 

[Shovert]

Coolan temp sender I think is a single wire sender for coolant Light in dash. So it won't be on the PCM diagam. I don't know about the VSS sensor. Maurice

 

[rubydist]

iirc, the factory oil pressure sender is simply a switch that closes (opens?) at somewhere around 6 psi. The oil light is on when the pressure is too low, off when above that.

 

[3d914]

Thanks for the info. Are there any special wattage associated with the lamps?

Wouldn't there be some kind of gauge for the coolant temp?

 

[rubydist]

the stock cluster has a coolant temp gauge. i don't recall the resistance values for the cold and hot settings on that.

 

[rbruso]

I can bring over the whole cluster from the '91 parts car, though I'll probably keep the speedo head. I figure you're probably using the stock speedo on the 914.

There are two coolant temp senders. The one wire sender is used for the dash gauge and doesn't talk to the ECU at all. The two pin sensor talks the the ECU. They're both located in the mess by the thermostat.

I am planning on pulling apart some of the '91 next weekend.

 

[Shovert]

On mine, SHO in Mustang. I installed the one wire Mustang water sensor in place of the SHO one and same for the oil. That way it would work on the Mustang gauges. Can you do same for using Porsche one's or aftermarket? Sorry for my lack of knowledge does a Porsche have a "coolant or heat type of gauge" Maurice

 

[rbruso]

The 914 was air cooled, so definitely no coolant light. I don't think it had an engine temp gauge either.

On other older air cooled VW cars you knew it was overheating when it started running worse under load.

 

[SHOtime2511]

I'd advise to buy gauges with a min/max light option.
There are some really cool ones now days where the whole back lighting changes based on your preset values.

 

[3d914]

Thanks guys.

Maurice, the one wire light/gauge is easy - stock 914 had both oil pressure and head temp. I'm sure the resistance on them is different. If I can find the resistance for the ECT that would be helpful.

rbruso, thanks for the offer on the cluster. At the least we may be able to get a resistance range off the temp gauge and I can find an aftermarket one similar.

As Brain suggested I may have to go with aftermarket for some gauges, but I'll still need to track down the resistance numbers if I'm to get the right ones. For the bench test I'll stick to idiot lights for most things.

 

[Shovert]

Here is link to ECC-iv sensor values. A little unsure if applies to to SHO. Would be easy enough to find out with ohm meter and thermoter and some boiling water for the ECT.
http://www.rothfam.com/svo/reference/sensors.pdf Page 4 for ECT.
2.07 K ohms for 212 F
24.27 K ohms for 86 F
Maurice

 

[3d914]

Excellent thanks. I can cross-check the part for some of the vehicles they listed. This kind of data is great. I never get bored with the details.

 

[3d914]

FYI,

I checked out the ACT (Air Charge Temp sensor) in the PDF and it does apply to the 3.0L Taurus/SHO. I'll also try to verify the Coolant Temp sensor (ECT), but I'm seeing two types in the parts catalog; a single connector and a double connector type. IIRC the SHO has a double-connector type (same as PDF). Curious.

 

[rbruso]

The SHO uses the single connector sensor for the idiot light and the dual connector sensor for the computer. You should have both of them screwed into the water manifold near the thermostat.

 

[Off Road SHO]

Actually I believe the single wire sensor is for the gauge and the double wire is for the Computer. If an idiot light illuminates on the cluster, it was told to by the computer.

Tom

 

[rbruso]

Actually I believe the single wire sensor is for the gauge and the double wire is for the Computer. If an idiot light illuminates on the cluster, it was told to by the computer.

Tom

Sorry, meant gauge not idiot light. The non-computer feed is one wire, the computer feed is two.

 

[3d914]

Actually I believe the single wire sensor is for the gauge and the double wire is for the Computer. If an idiot light illuminates on the cluster, it was told to by the computer.

Tom

Sorry, meant gauge not idiot light. The non-computer feed is one wire, the computer feed is two.

OK, to make sure I have this correct - the single wire drives the temp gauge (I don't have resistance ranges for it) and the double wire (do have resistance ranges) communicates with the PCM. So I still need to dig up resistance ranges for the single-wire sensor.

 

[rbruso]

OK, to make sure I have this correct - the single wire drives the temp gauge (I don't have resistance ranges for it) and the double wire (do have resistance ranges) communicates with the PCM. So I still need to dig up resistance ranges for the single-wire sensor.

Let me check the Probst book to see if it has approximate ranges for the sensor. I know it has a test procedure, just can't remember if it has reference values.

Per RockAuto, the one wire sensor was used on just about every FLM car throughout the 80's and 90's (and some before and after just for variety). So, in a pinch if your sensor goes out you can raid the neighbor's 1970 Econoline or their 2001 Mountaineer.

I didn't get the '91 cluster pulled this weekend, as there was too much other stuff going on. (Yard work sucks. Glad we only have to deal with it for a month or two a year.)

 

[Phoenix]

You can always grab a gauge kit from speedhut , they make all kinds of gauges , with or without high/low lights included in the gauge , theres also a turn signal option within these gauges. They are fully electric , and you can have a speedo that works with a GPS.


these are their cheep line , bought 2 sets from them.

 

[3d914]

Let me check the Probst book to see if it has approximate ranges for the sensor. I know it has a test procedure, just can't remember if it has reference values.

Per RockAuto, the one wire sensor was used on just about every FLM car throughout the 80's and 90's (and some before and after just for variety). So, in a pinch if your sensor goes out you can raid the neighbor's 1970 Econoline or their 2001 Mountaineer.

I didn't get the '91 cluster pulled this weekend, as there was too much other stuff going on. (Yard work sucks. Glad we only have to deal with it for a month or two a year.)

Rich, a thought occurred to me (yeh-scary I know) that wouldn't the temp/resistance range for the single-wire sensor be the same (or close) as that of the PCM sensor?

Don't feel bad about the cluster. At the rate I'm going this thing won't get running till November. Spent all weekend on car maintenance and yard work - no project time. Next weekend looks to be the same.