T660 speedometer problems

[senorbac]

Hello, my 2012 KW. T660 has a speedometer malfunction ONLY when weather gets below 50 to 45 degrees cold. The speedo goes haywire and doesn't read right. No problems at all during warm months. I have already changed my speed sensor in the transmission tail and same thing. Any clues as per why only malfunctions in cold temps?

[Rawze]

Could it be a bad connection on the circuit board in the back of the unit? - Does it start working when the insides of the cab warms up good?

just some guessing here.

[senorbac]

(11-16-2018 )Rawze Wrote:  Could it be a bad connection on the circuit board in the back of the unit? - Does it start working when the insides of the cab warms up good?

just some guessing here.

Could it be the connector on the speed sensor? Since no it doesn't get any better if the inside cab gets toasty.

[Rawze]

(11-16-2018 )senorbac Wrote:  

(11-16-2018 )Rawze Wrote:  Could it be a bad connection on the circuit board in the back of the unit? - Does it start working when the insides of the cab warms up good?

just some guessing here.

Could it be the connector on the speed sensor? Since no it doesn't get any better if the inside cab gets toasty.

could be. Maybe check what the engine is reporting to verify it is not the gauge. Paccar products seem to have speedo gauge issues a lot, so just saying to don't rule it out.

Also check the plugs that go into the cab where they meet the firewall.