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tbcbusguy
New Member
5 Posts |
 Posted - 01/21/2019 : 06:52:31 AM
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Hello, I have several 01 Thomas Saf-T-Liner buses. Been having problems with the heaters and defrosters in several of them.
Here is the issue; the defrost and the step well heater will work then randomly shut off tripping the circuit breaker, my circuit breakers auto reset so turn the heater switch off and a short time later it works until it trips it again. The rear/passenger heaters will also do this on a few of the buses, but none of the driver heaters have ever had a problem.
What I have done so far. I have replaced the switch, relay, resistor, motor, and circuit breakers. I've talked to 2 electricians and 3 other mechanics and no one has been able to figure anything out with it. I was thinking wiring, but I have run a wire straight from the electrical panel to the switch and rewired from switch to motors and still have the problem.
I'm totally at my wits end with them and my drivers are constantly complaining about the issue. Any help is greatly appreciated! |
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muddywater
Senior Member
USA
50 Posts |
Posted - 01/21/2019 : 1:59:48 PM
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| Have you tried a heater motor? You haven't mentioned that, and 95% of my heater problems are inside the motor, or a connection problem. |
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tbcbusguy
New Member
5 Posts |
Posted - 01/22/2019 : 06:11:51 AM
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| Yes, replaced motors on majority of the problematic buses. A couple buses it seems to help them run longer before they shut off but still they shut off |
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Fastback
Top Member
1500 Posts |
Posted - 01/22/2019 : 07:46:28 AM
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You'll have drivers that immediately upon starting bus throw every heater fan on full blast and/or complain about the heat while half the passenger windows are in varying stages of being partially open.
I would be tempted to experiment by temporarily disabling the high speed or doing an amperage draw test of the motors on each speed and comparing to circuit breaker rating. |
Why yes, the ORIGinal CHARGER is a Fastback |
Edited by - Fastback on 01/22/2019 07:47:01 AM |
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Heater/defrost work intermittently
