4.3 TKS 15 amp fuse blowing

Dale Harris

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Jan 7, 2021
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2
2009 Tahoe Q5I with 4.3 TKS 15 amp fuse blows once temperature reaches 160 I can put a 20 amp and it doesn’t blow
 

alldodge

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The original TKS came with a 20amp fuse, later it was changed to 15amp. Most likely your temp switch is shortly out. The temp switch supplies power to the TKS module once temp is reached. I'm thinking the switch is also putting some of the power to ground. Can also be the TKS module is starting to draw more current

This doesn't help narrow it down to which component, just the 2 options. Here is the module test

TKS Bench Test.jpg
 

alldodge

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Staff member
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TKS Module Resistance
Ambient temperature
21° C (70° F) 35-45 Ohms
-6.6 ° C (20° F) 55-70 Ohms
 

Dale Harris

Recruit
Joined
Jan 7, 2021
Messages
2
Thanks I believe you are correct today once it reached 160 and it blow the 15 amp fuse so I replaced the fuse and disconnected the temp sensor and started it and let it run for about 5 minutes then plug temp sensor back in immediately it blew the fuse I pulled the sensor 866089 and I’m going to order a new one.
 
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