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viper 5901 temp sensor

Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=116720
Printed Date: July 05, 2025 at 4:52 PM


Topic: viper 5901 temp sensor

Posted By: alarmgeek
Subject: viper 5901 temp sensor
Date Posted: October 04, 2009 at 9:09 PM

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.

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Replies:

Posted By: alarmgeek
Date Posted: October 04, 2009 at 9:12 PM
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.




Posted By: i am an idiot
Date Posted: October 04, 2009 at 9:45 PM

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Posted By: i am an idiot
Date Posted: October 04, 2009 at 9:49 PM

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Posted By: alarmgeek
Date Posted: October 05, 2009 at 9:42 AM

(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.





Posted By: bizill
Date Posted: October 06, 2009 at 6:04 PM

man, i sooooo wanna do this.  but i already have no warrantee as it is.  i'd hate to somehow ruin my 5901.





Posted By: alarmgeek
Date Posted: October 06, 2009 at 6:32 PM

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.





Posted By: bizill
Date Posted: October 07, 2009 at 10:02 AM
...thus making this seem more and more tempting.





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