One of the reasons I bought the Viper 5901 was its ability to program the remote start based on temperature. My dog travels with me a lot and I wanted the AC to automatically maintain temp for him. After installing the alarm I realized as most have, that the temp readings are 10 – 15f off from the actual cabin temp. I believe this is caused because the temp sensor ,(thermistor), is mounted inside the alarm enclosure and the circuit board gives off some heat.
This is how I made the temp readings more accurate. I removed the sensor from the circuit board and soldered it on the end of a 2’ cable. I mounted the sensor near the center of the dash, underneath but not touching the dash directly. The readings are now within 1 degree of actual.The following pictures should help explain what I did.






OK, I just read the rules and member levels and such. Well, I thought I was helping wto tell others what I did with an explanation and pics but that failed miserably. Sorry to those that are interested, it works good just wish I could share.
(i am an idiot), thanks for posting the pics, here is the text to go with them,
One of the reasons I bought the Viper 5901 was it's ability to program the remote start based on temperature. My dog travels with me a lot and I wanted the AC to automatically maintain temp for him. After installing the alarm I realized as most have the temp readings are 10 - 15f off from actual cabin temp. I believe this is caused because the temp sensor, (thermistor), is mounted inside the alarm enclosure and the circuit board gives off some heat.
What I did to make the readings more accurate was to remove the sensor from the board and put it on the end of a 2' cable that I mounted near the center of the dash, underneath but not touching the dash directly. The readings are now within 1 degree of actual. The previous pictures should help explain what I did.
man, i sooooo wanna do this. but i already have no warrantee as it is. i'd hate to somehow ruin my 5901.
As you can see it is a pretty simple mod. It does require a low wattage soldering iron and preferably a solder sucking tool. Once you have the thermistor off the board the rest is easier. FYI there is no polarity to the thermistor.
I lifted the " you voided your warranty" sticker that covers one of the case screws with a razor blade and moved it to the side. I feel i could put the thermistor back on the board without it being obvious, if I needed to. Then there is the issue of installing the alarm myself which I guess voids the warranty anyway so what the heck.
I have had Vipers in 4 of my own cars over the past years and installed another 6 and never had problems with the electronics.
...thus making this seem more and more tempting.