stupid question....temp gauge and sender, temp doesn't register...where is sender? Options

[jim912928]

Ok, my temperature gauge doesn't register at all. Car runs fine, but I really don't want to run it long without knowing what temperature range I'm running in. So, I need to begin diagnosing this problem but first I'd like to know where in the heck the temp sender is located? I'm guessing it can only be 1) wiring, 2) gauge or 3) sender. So, once I find out where the sender is how do I test it?

Car is a 75 1.8l....again, as usual...thanks in advance!

[davep]

The temp sensor is located on the bottom of the engine, not far from the alternator. The sensor sticks out at an angle. The is more than likely a wiring problem. Check that first.

[d7n7master]

What temp sender are you asking about? Oil or head temp?
Oil temp sender is in the taco plate. If it's orig. wiring - replace the wires. They're 30 years old... (IMG:style_emoticons/default/agree.gif)

[jim912928]

it's the factory gauge in the center console. I assumed this is oil

[lapuwali]

If it's orig. wiring - replace the wires. They're 30 years old...

Wire doesn't tend to go bad with age. Connectors, however, do corrode and fatigue over time. With any electrical problem in any old car, 90% of the time, it's a connection problem. No need to replace the whole wire to fix, just the ends, with new connectors, properly attached.

[Brad Roberts]

Guy's..

Last time I checked. NO 1.8 engine has a oil temp sending unit. It sounds like someone installed a center gauge console into a 1.8 car. His engine wont have a sending unit.



B

[jim912928]

not sure if someone installed a console or not. It's definitely a complete factory wiring setup as I've had this interior totally out and all the wiring looks to be around the same age and nothing is "patched" in. This is a 75 also.

[Brad Roberts]

All the cars have the wiring for the center console. The console gauges plug right into the chassis harness. Doesnt mean there is anything connected on the other end.

Check this:

The factory "rolled" up the temp sending unit wire directly below the battery tray. See if you have a wire there "rolled" up should be green with a red stripe if I recall correctly.


B

[jim912928]

did a quick check..no rolled up wire under the batter tray...actually no wires under the battery tray other then the enclosded harness. I didn't lift the car up to try to find a sender.

If 1.8s did not have a temp sender then how did you know if you were overheating? There is no temp indicator in the gauge clusters...and the 75 1.8/2.0 owners manual only shows 1) oil temp gauge in the console or 2) oil temp gauge in the dash....this last one showing optional and is located where the parking brake "flasher" light is. Mine definitely doesn't have the latter. So the only temp indicator is the one in the console.

Guess I have to go jack up the car and crawl underneath.

[Brad Roberts]

That wire comes out of that main harness under the battery tray and passes through a grommet on the engine shelf (if it is there). You should'nt have to jack the car up. From the drivers side just in front of the wheel.... look 1/2 inch back from the engine crossbar. Basically look across the bar until you see the first sign of the engine. The "taco plate" is right there. If it has a temp sender in it.. you wont see it. The sender has a cover on it. Look for a single wire leading to the taco plate.

Only the 73 and 74 2.0's had a gauge for reading oil temp....opinions may differ... but this what I see day in and day out..


B

[jim912928]

Ok, I think I found the "taco plate" assuming it is on the corner of the engine, bottom, closest to the drivers side. It's (I'm guessing) 3-4" in diameter. Mine has a cylindrical formed piece (part of the cover) that comes out at maybe a 45 degree angle towards the front of the car with a 1/4-1/2" hole in the end of it. There is no wire going into it and I couldn't get an angle or stick my finger in far enough to feel if there was a connector end in there.

A stupid question though...if 1.8's have no temp sensor or temp indicator..how would one know if they were overheating their engine?

Thanks, every post is a learning experience for me!

Jim

[Brad Roberts]

You found it. Now you need to locate the wire coming from the main wiring harness. The 73/74 cars have it where I described above.

Dealing with the late model cars is something I'm lacking. ALL of the 75-76 cars could have came with temp gauges...Porsche was purging stock on all these items.. so who knows what is exactly in them and what isnt. Good news is: you have the taco plate and you found it quickly.

B

[Brad Roberts]

A stupid question though...if 1.8's have no temp sensor or temp indicator..how would one know if they were overheating their engine

Just like school... there are NO stupid questions. Everyone is here to learn.

I *guess* Porsche didnt feel the need prior to the 2.0 engine to have a temp gauge.

I service a few 2.0 75/76 914's and I dont recall any of them having temp gauges unless they have a center console.

B

[type47]

i combine "1.8" and "temp gauge doesn't work" with PO put in console but didn't hook up sender. proof is when he checks taco plate and no sender or sender is there. guess the factory wanted the 1.8's to overheat so you would put a 2.0 in (IMG:style_emoticons/default/biggrin.gif)

[SirAndy]

to save money ...

oil temp sender was part of the "appearance group" upgrade (middle console with gauges) ...

they made you pay for it ...

as far as i know, NO 1.7 or 1.8 came with the sender/gauges by default, certainly NO car before '73, the early cars don't even have the wires in the harness to hook one up ...

(IMG:style_emoticons/default/wink.gif) Andy

[jim912928]

Brad,

I went out again and looked at the main wiring harness under the battery tray....moved it around alittle and running underneath it was the greenish wire with a male connector at the end of it (about half way up the harness right under the battery tray.

So:

1. I have the wire in the rear engine compartment
2. My taco plate has the "bulge" on it with a hole for a sender
3. guess I'll have to really get under the car so I can see if there is indeed a sender in there (can't feel anything via the tip of my finger)

Thanks again for the advice on what to look for. If I'm lucky, there is a sensor in there and I only need about 2 feet of wire!

Jim

[SirAndy]

If I'm lucky, there is a sensor in there and I only need about 2 feet of wire!

that is correct!

but even if you don't find a sender, all you really need is a plate with a sender, drain the oil, get the right crush-washers, put on the new plate, cut some 2 feet of wire, put new oil in and you're ready to go ...

(IMG:style_emoticons/default/wink.gif) Andy