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Autometer Transmission temp gauge problem.

18K views 20 replies 5 participants last post by  Silver 
#1 ·
I got done installing my Autometer Transmission temperature gauge today. Well, yesterday but was still working on the paint for the pod today so just had it hanging there yesterday although it worked. Then today I put it in the pod and thought all was good. I went riding in it tonight and all was great for the first 5 miles or maybe even 10. About time it got up to temperature I noticed it shot up to 250 degrees which is as far as it can go. Well, a little past 250. At first I thought it had over heated or something although I thought that was odd. I started pulling over to check it. Everything I can see was hooked up just fine. If you hit the gas hard it would go back down to right around 150 where it should be and was before it messed up. If you slam the door it will also go down to around 150. That kind of made me think it was the gauge but if you disconnect the sending unit wire it goes back down to 100 which is the lowest it can go. If it was the gauge would it still do that? If you get on the gas hard it will go back down then it will start going crazy all over the place then back up to as far forward as it can go. Any idea's? Is there anything I could have wired wrong that would cause this? I'm positive it's wired up right just wondering if something could have happened to one of the wires causing this or does it sound like a faulty gauge or faulty sending unit or what? I thought it was odd it worked great for a bit before doing this.
 
#3 ·
I want to check my wiring tomorrow when it's light. It seems like maybe something happend as it was working fine. It's still connected at the sending unit and at the gauge but I couldn't see in between there. Does it sound like it's grounding out or could it be a bad sending unit?
 
#6 ·
On 2008-10-16 20:58, FirstGenDodge01 wrote:
definetly a wiring issue. its grounding out somewhere. If you ran it thru the door jam :wall: :wall: then thats your problem.

good luck.
Nope didn't run it through the door jam. It just was moving the needle if I slammed the door. I ran it through the firewall then down and into a wireloom which I ran overtop of the transmission to the passenger side then hooked it into the sending unit. I put it in the wire loom overtop of the transmission as I figured it may get hot and extra protection wouldn't hurt. I did you a solid wire instead of the normal braided type wire. I may check and see if I can find a problem and if not I may just run new wires with the normal braided kind. Shouldn't be that hard. I will just have to get more connectors as I think I used up my last ones on these wires.
 
#8 ·
Since you came off the front servo on the trans, make sure the wire from the sending unit isn't touching anything hot that might have melted the wire jacket, exposing the wires. Also check the ground wire for your gauge to make sure it is a good ground. Lastly, make sure all the wires on the back in the gauge are not toching each other inside the pod. Some of those gauge pods don't have much room inside, and when you stuff a gauge in the, the wires can get all pushed together. If you have any exposed wires, they might touch each other once scrunched together.
 
#9 ·
Found out the problem. The sending unit wire had melted well, the shielding had so it was grounding itself out. I'm redoing it now but I'm unable to figure out a way to run the wire so that it doesn't happen again. I'm going to have to keep looking for a way to run it.
 
#10 ·
you can get High Temp wire loom i would look into that. otherwise i would run it in the cab and then down thru the 4x4 gate it its manual shift 4x4. or just run it under the carpet and drill a hole for it. Deff lot more work but worth it to avoid issues in the future.
good luck
-firstgendodge01
 
#11 ·
Now I'm wondering how accurate this is. Wayne told me the servo port wasn't as accurate as the pan but I didn't think it would be much off. Anyway riding around town I was around 150 after 10 minutes of driving or so. It might have been just a tad above that but right around 150.

Now today it was around 125 which was a few miles of in traffic and then interstate for a while after that then some backroads. I was moving around 55-70 most of the time though and it was in the 40's or low 50's today instead of like the other day when it was fairly hot.

I'm not sure if it's reading low or if it was around 125 since it was cold. Tonight it went down even lower coming down the interstate running 65 or so. Got right above 100 but in town for the few miles I went it went up to around 125 then.

I do have a pretty big B&M transmission cooler. Does this sound about right being that it's fairly cold outside or does it sound way low?
 
G
#12 ·
my sender is in the drain plug hole, with it 45 degrees right now mine runs about 125 degrees, on a 80 degree day at highway speeds im at 165,regular driving it sits just under 150 on a 75-80 degree day, the pan is the most accurate place to put it
 
#14 ·
Well, at 45 degrees or so I was getting about 125. It was around there then went slightly lower on the interstate. So does it sound like I'm getting a bad reading or does it sound normal? What should I check if I'm getting a bad reading? It was around 125 on the interstate this morning the whole time and it was a little warmer but not a lot. My buddy seems to think it's because I have the B&M cooler which he has said how nice of a cooler it was as have many others. I'm not sure if that would make it that cool or not though.
 
#15 ·
After I re read what you wrote, I think I understand what you were saying now, I thought you were saying the reading was in the 40s or low 50s and after re reading it I now understand you were talking about the temperature.
 
G
#16 ·
the port can have a 10-20 degree hotter reading than the pan, so i would say yours may be reading wrong, then again the cooler may be working that good.

did you use a premium fluid like amsoil or royal purple? those can get 30 degree lower temps as well so if you have the big cooler and a premium fluid i could easily see it reading cold
 
#17 ·
Yup the outside temperature was mid to high 40's to low 50's. The gauge was reading slightly over 100 going down the interstate at night and about 125 around town after a couple miles of town driving. Not many miles just a couple. Then during the day it was reading 125 or so going down the interstate where the temperature was probably low 50's outside.
 
#18 ·
it's reading right. My pan temp barely got above the lower limite needle peg (100* on my Sunpro analog) when I was in KS and the weather was cold - 50* or cooler.
I attribute it to the Hayden external cooler getting extremely cold air and cooling the warmed fluid coming from the integrated tranny cooler in the radiator.
In normal TX temps (85*-100*) mine hovers around 160-170* empty.
Tool cool won't hurt anything in the tranny, too warm will.
 
#19 ·
Well, towing a 5x8 utility trailer with a stove on it last night up a steep mountain gravel road where I had to go slow it got up to about 200 degrees but no hotter than that. That's okay right? I don't need to change the fluid or anything from that since it wasn't much hotter than that do I?
 
#20 ·
no, 200 is still well within operating limits of the ATF+3 and +4 fluid.
215* or higher I would be concerned, anything over 220* I would either slow down or get a larger cooler but that's just me.
If you can get up to 38 mph or faster your T/C will lock (with O/D off) and your tranny fluid temps will drop significantly.

If you want it cooler consider mounting a small e-fan on the tranny cooler. I did that for towing in traffic and it makes a huge difference in cooling ability when traveling slower than 20 mph.
 
#21 ·
Normal operating temp (the temp at which you should also check the fluid level) is in the range of 180-195 F. Anything over 210 F should start to make you take some notice in my opinion, but not really in any danger area yet, just be vigilant. I wouldn't worry about changing your fluids unless you see temps over about 240 for an extended period. According to the Chrysler service manual, the trans temp light (which is the manufactureres way of warning you that your trans temps are getting too hot) doesn't even illuminated until 275 F.

Also:
-The PCM prevents engagement of the converter clutch and overdrive clutch when fluid temperature is below approximately 50 F.
-If fluid temperature exceeds 260 F, the PCM causes a 4-3 downshift and engages the converter clutch. It will also illuminate the overdrive Off light and prevent you from going back into fourth (overdrive) until temps get below 260 F.
 
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