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Daniel Wilson
Daniel Wilson,
Category: Medium and Heavy Trucks
Satisfied Customers: 4291
Experience:  Owner at DJ Wilson
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I have a 1999 Freightliner that the brake lights don't work.

Customer Question

I have a 1999 Freightliner that the brake lights don't work. I bypassed the switch and they came on so I replaced the switch and still no luck. It is an ex military vehicle we converted into a water tender. What and how should I check on the air side to determine what is bad? The VIN Is 3FRXW7FM6FV528032
JA: What is the complete model and serial number of your machine?
Customer: The vehicle model number is *****
JA: Anything else you want the equipment mechanic to know before I connect you?
Customer: No
Submitted: 1 month ago.
Category: Medium and Heavy Trucks
Expert:  Daniel Wilson replied 1 month ago.

Hi my name is***** will be glad to try to help. If they work by bypassing or jumping the terminals but not with a new switch you might have the wrong switch. Some are normally open and some normally closed but look identical but different part numbers.... Make sure they parts store did not get that mixed up. Let me know

Customer: replied 1 month ago.
If that were the case, wouldn't the stop lights be on when you're not pressing on the pedal?
Expert:  Daniel Wilson replied 1 month ago.

Yes. That information was not posted. I was going by you jumped the circuit with a jumper wire and they worked. Maybe I misunderstood. So with a jumper connected do they work? and then go out with the jumper disconnected?

Customer: replied 1 month ago.
Expert:  Daniel Wilson replied 1 month ago.

There has to be a problem with that switch. With the wires disconnected, test with an OHM meter continuity across the switch with both the brake pressed and released. sounds like the new switch may never show continuity and is defective. Let me know

Expert:  Daniel Wilson replied 1 month ago.

Also check and verify that port is getting air pressure with the brakes applied.

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