I noticed in a pic you put up that a sender just had one wire attached to it. Those senders must be really old stuff, since the current Autometer gauge senders come with connectors having two wires. (See the attached image.) I suspect you are on the right track with the additional ground wire.

Well, I added the grounds for the senders and everything is working the way it should be. I wired the lights to the cigarette lighter light circuit this time.

I don't think those are necessarily "old" sensors.
VDO makes both types for instance- the single terminal units are meant to ground through the threads, which is why they don't recommend use of teflon tape.
I'd wager that if Budd reinstalled without the sealing tape, the gauges would work fine.

:rofl: i rock this boost gauge only cuz i got it for free. it does the job so far...

i am having some issue with my autometer coolant temp gauge and was wondering if my problem might be related? when the car is running the coolant gauge will rise slowly and eventually peg out at the top. i can see from the haltech that the coolant temp stays between 185-195F so i know its not overheating. i decided to run a new ground from the gauge directly to the battery to see if that might be the problem but when that happens the gauge doesnt go above 160F or so. i have the sensor in the thermostat elbow. any ideas?

so your water temp gauge slowly rises till it'sd maxed out even though the EMS says it's fine?? hmmm.

Don't some of the FC have a plastic thermostat elbow? is your sender itself actually grounded?

Did you try removing the sender wire from the sender post on the back of the gauge and grounding that post? That should cause the gauge to max out right away.

Almost sounds like it's the sensor for sure though.

yep.

the sender is in a metal s4 elbow. how would i ground the sender? there is just a single wire on it running to the gauge.

Here you go, I made this myself!!

But anyways I used a small hose clamp to clamp the new ground wire to the sensor body itself.

Attachment 706276

hmm, ill try that, thanks.

Are you using teflon sealing tape?
If so, remove it.

ill have to check that as well. i will make sure to remove it. probably wont be able to check again until friday.

I did not read the WHOLE thread, but that wiring does not look correct, did you confirm your wiring?
The lights need to be wired seperate.


everyone rags on my mechanical gauges, I have been using Autometer mechanical gauges for 20 years, now with the standalone I confirm they are reading the same as the Wolf is reading.
The wiring is a light power and a ground, thats it. Best thing about mechanical is the gauges ALWAYS work, even when the car is off the temp still reads

the red fitting is for the water temp, oil pressure reads off a Mazdatrix adaptor and goes through a stainless braided line to the gauge in the dash, im going to add oil temp as well but im not sure where to mount it in the car yet.

http://robx-7.nopistons.com/d/1695-2/dp+004.jpg

Well, if you did read the whole thread you would have found out the wiring was not at fault.

The problem was simply that the senders weren't grounded very well. The coolant sender was installed in a silicone hose and needed an additional ground which I had forgot about. The two oil senders were installed using teflon tape which did not allow for a good ground through the threads, I grounded the body of the senders and have been very happy since then.

I am moving the water temp sender to the same location that yours are in by the way. Thanks for the input though.

If you have the adaptor that came with the gauge have it welded onto the housing, this gives you good threads and eliminates having to thread the housing itself

Thats a good idea. Thanks.

It's interesting how Autometer recommends the use of teflon tape for the sensor threads, when it effectively kills the ground of the sensor... May be the water temp sensor had a little clear spot of ground the first couple of times and lost it afterwards...

It's good to hear you solved your problem!!

By the way, somebody knows if aftermarket senders have standard voltage output across brands? I have an Invision S7 with broken oil pressure sender and AC autotechnics doesn't answer my mails. I was thinking off replacing the sender with an Autometers.

Well I completely forgot to ground the water temp sender in the hose adapter, it even has a ground screw right on the adapter.

I am kinda baffled as to why the two gauges worked initially but then stopped, guess they must have had a partial ground that worsened.

But I am relieved as well, it was driving me mad. I seriously do not enjoy when things goo wrong with my 7.

I'm looking around to try to find the specs for the different senders but I can't find anything on the Invision S7 sender. If you knew what the resistance values for each sender was that would tell you if it would work.

I would call the company and speak to someone in person though first.

AC AutoTechnic
Advanced Concepts
900 W. 10th St.
Azusa, CA 91702

Tel. 626.812.8388

I was thinking of calling but remember that I'm in Costa Rica, that means I'll have to make an international call.

May be some day I will :rolleyes:

I'll try to find someone with Autometers installed and test the gauges against the installed senders.

my problem seems to be coming from the adapter i have the temp sender plugged into. its just too slow to react.

NJGB...what size is the hose adapter you are using? 38MM?

Cerm, I'll do you a favor and call them myself. Might have to wait till monday but let me know what exactly you want me to ask them( for a replacement sender or just the specs for resistance?). Or I could measure theresistanc eofv my oil pressure sender.....



87, Yes I'm using a 38mm adapter - they are cheap on ebay.

Did you try to add the ground to the sensor body? What material is the adapter made out of?? Is the sensor getting good contact with the coolant?

Thank you Budd! What I wrote to them (and never got an answer) was if they sell replacement sensors. I need the oil pressure and water temperature sensors for the Invision S7.

If they don't sell them then I will try to use some other brand sensor. Then you can help me with you sensors resistance readings, to see if they'll work with my gauges.
Thanks again!

Hi NJGreenBudd, I did my homework and tested the gauges against a variable pod resistor. Didn't have too much time so I only did a three point mapping of the resistance against the values shown by the needle.

For oil pressure I have that:
- Minimum Oil Pressure 0 PSI = 0-10 ohm
- Halfway Oil Pressure 50 PSI = 40-50 ohm
- Maximum Oil Pressure 100 PSI = 90-100 ohm

So it seems that oil pressure sensor range is from 0 to 100 Ohm and has an almost linear response.

On the other hand, for water temperature I have that:
- Minimum Temp 105 deg F = 90-100 ohm
- Halfway Temp 202 deg F = 10-15 ohm
- Maximum Temp 300 deg = 0-5 ohm

So it seems that temperature sensor range is from 0 to 100 Ohm, like the oil pressure sender, but it has a exponential response and it is inversely proportional to the temperature.

I have found a web site of a sensor builder that sells generic senders for every kind of use. I'll search for a suitable sensor but I'll thank you if you can measure the sensor resistance to see if autometer's are close to what I need.

Thanks again!

have autometer z series boost and water temp gauge..i gave up on the water temp did the exact same responses as you..they lit up with power everytime but couldnt get the damn thing to work..my water temp sensor is threaded into the back of my water pump housing exactly how the previos post was..so i need to remove the teflon tape from the sensor then ground the sensor directly like budd previosly posted..? this thread has changed my life:)

i installed one of those hose adapter things, ran a new ground to the gauge and to the adapter, and now it works great.

Excellent!

Good to hear that this is helping other people. It was such a simple problem but seems to be common.

Hopefully other will benefit as we have.

Good day fellas.