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Sun Apr 28, 2013 8:59 pm

Hello, I have the VDO oil temperature gauge ( http://www.mamotorworkstv.com/vw/product/oil-tempe...f_196135/) and it is not working. I have it wired to hot when the key is turned to the on position with a good ground. The signal wire is wired to the oil temp sender. When I run the car, the gauge reads 300 at all times. Could it be the type of sender I am using? I am using the sender that replaces the plug for the oil relief.

Sun Apr 28, 2013 10:12 pm

Unplug the wire to the sender. Measure the ohms resistance of the sending unit when cold, and again when the engine is warmed up. That should help troubleshoot whether the sender unit is OK. VDO should have ohms spec, call their Tech Line.

Tue Apr 30, 2013 1:11 pm

OK I measured the resistance. I found a topic on here from 2011 where it said that the resistance needed to be high when it was cold, and the resistance low when it was hot. This is exactly what the sender did, It read 1240 ohms cold, and 210 ohms hot.

Still, my gauge reads 300 F constantly, right when I turn the key. I just routed a new wire to the sender, so I dont think it could be the wire. Where do I go from here? Do I have it wired to hot in run wrong?

Tue Apr 30, 2013 2:18 pm

alexvw wrote: OK I measured the resistance. I found a topic on here from 2011 where it said that the resistance needed to be high when it was cold, and the resistance low when it was hot. This is exactly what the sender did, It read 1240 ohms cold, and 210 ohms hot.

Still, my gauge reads 300 F constantly, right when I turn the key. I just routed a new wire to the sender, so I dont think it could be the wire. Where do I go from here? Do I have it wired to hot in run wrong?

Measure the resistance at the back of the gauge or as near as you can get. Sounds like a connection is shorted, low to no resistance on the sender so the gauge is reading max? If so, follow the wires. Does the gauge drop to 0 if you pull the sender wire or what does it do?

Tue Apr 30, 2013 4:18 pm

From the tech section of Egauges.com

My temperature gauge reads high?
Answer: Isolate ground (wire) on temperature gauge

I also read someplace (wish I could find again) that VDO has reversed the power and sender on the inside on some gauges. Just a suggestion but you could try and reverse them.

Tue Apr 30, 2013 7:06 pm

Nucvegas wrote: From the tech section of Egauges.com

My temperature gauge reads high?
Answer: Isolate ground (wire) on temperature gauge

I also read someplace (wish I could find again) that VDO has reversed the power and sender on the inside on some gauges. Just a suggestion but you could try and reverse them.

Reversing the wires, it started smoking :lol: I turned the key on and off 5 cycles and the gauge started working again? Still at 300F though. What do you mean isolate the ground wire? Isolate it from other wires, because I do have it at a junction with other ground wires.

Tue Apr 30, 2013 7:12 pm

Sorry about the smoke :oops:

Isolate the ground: have the ground all alone, not in a junction. That could be giving you a little feedback on the ground. It is worth a try to go it alone.

Tue Apr 30, 2013 7:41 pm

Nucvegas wrote: Sorry about the smoke :oops:

Isolate the ground: have the ground all alone, not in a junction. That could be giving you a little feedback on the ground. It is worth a try to go it alone.

I will give it a shot, thanks

Sun May 05, 2013 5:07 pm

i think i have the same issue, any updates on this ?

thanks

Sun May 05, 2013 6:24 pm

isolating the ground did not do anything either, so far I have tried to isolate the ground, ran a new wire when installed, reversed the wires and ended up with smoke but the gauge still works, and the sender has the correct resistances... what else can I do? Again, it stays all the way to the right and never leaves the 300 F reading.

Sun May 05, 2013 6:25 pm

I may try to run a ground right the the battery for the heck of it

Wed May 29, 2013 11:25 am

If I remember correctly, the input range for that particular gauge should be somewhere around 244-30. If you're getting 12XX ohms then it's obvious that the gauge would be pegged. I would probably look into a new sending unit that matches your ohms on the gauge. There are similar ones out there. Most people state these VDO sending units can be anywhere from 12-40F off. That's a hell of a lot better than 300F. Might not be deadly accurate, but with a little thought process can atleast give you an idea of where you're at.

I'd rather have a gauge tell me I run 250 on the freeway all the time in 90* weather even though it may not be correct, it's consistant. Now when it goes to 280* that's when I know I have a problem!

Sun Jun 02, 2013 7:13 pm

I don't know what it would do, but what size wires are you running as ground? I just installed a vdo tach and oil temp(bought the sender recommended by aircooled.net for the gauge) and the directions for both said use 14 gauge for the ground. I did that, and used 16awg for everything else and they both work swell. good luck!

Sun Jun 02, 2013 7:51 pm

there are also 2 grounds and two powers on mine. the light has its own +and - and the there is a ground and power for the indicator. don't want to condescend but are you using the right ground😃

Sun Jun 02, 2013 8:15 pm

Still doesnt work :( They both have power and I both have them going to a common ground, all together. It is 16 AWG wire...

Mon Jun 03, 2013 2:40 am

does the gauge do anything if the wire is disconnected from the sender?

Mon Jun 03, 2013 9:32 pm

Opticsguy wrote: does the gauge do anything if the wire is disconnected from the sender?

When it is disconnected from the sender, it goes max at 300. When it is connected, it goes max to 300. Also, I tried a different sender and just left it hanging there from the wire, same thing, it goes to max at 300. I tried to isolate the ground and still the same thing. Is this a gauge issue??

Mon Jun 03, 2013 9:40 pm

I would suggest looking for a sending unit that's 244-30 specifically or a gauge that's 1240-210 specifically. Sounds like you have one or the other but not both.

Mon Jun 03, 2013 9:42 pm

Wiring:
We recommend 16-gauge wire except for the final ground wire which should be
14-gauge.
Wire the gauges in series from a (+) accessory source which is not already overloaded
with other accessories such as electric fans and air conditioning. The ground
is also run in series including the light socket ground. The final 14- gauge wire
needs to be connected to a good ground such as the engine block ground strap or
the battery ground itself.
All wiring should be of high quality stranded wire with good insulation. Take care
to avoid hot engine components when running engine compartment wire. Use
grommets when running wire through the fire wall. If your gauge’s pointer moves
noticeably when the lights, fans, or air conditioner comes on, you are wired into an
overloaded circuit either on the hot or ground side.

I just read this from VDO troubleshooting. I have the circuit in parallel with other circuits. It could possibly be overloading the gauge causing it to always spike high. I will rewire it when I get a chance and give it a battery ground if needed. If this does work, what should I be seeing as a normal temp. reading? :)

Mon Jun 03, 2013 9:52 pm

camaroboi13 wrote: I would suggest looking for a sending unit that's 244-30 specifically or a gauge that's 1240-210 specifically. Sounds like you have one or the other but not both.

I have this exact sender = http://www2.cip1.com/ProductDetails.asp?ProductCode=VDO-323-064

Exact gauge = http://www.mamotorworkstv.com/vw/product/electric-temperature-gauge-12v_111155/