M923a2 Brake light problem

[603hellmutt]

Looking at purchasing a new truck, found this 923a2 for a decent price. Everything on the truck seemed to be good up until the brake lights, it has a newer style push button light setup that I have no experience with. Blinkers and everything work other then brake lights. The brake lights will flash quickly then not come back on. Is it still a good deal to purchase it and fix or should I look elsewhere? I've read it could be as simple as the brake light switch. If this is in the wrong place I apologize I'm new.

 

[mdemars03]

If it was me first thing I would do is get a jumper for the brake light switch and see if it is something as simple as a bad switch. If that is the case it is a very easy fix and if the price is good it would be worth looking onto in my personal opinion. There are several little things to check. Make sure all of the connections are tight as well as that can cause problems. Also check any grounding points to make sure you have a good ground. I had a horrible time with brake lights and turn signals and found it to be a bad ground. Good luck with it and hope it works out like you want.

 

[o1951]

Looking at purchasing a new truck, found this 923a2 Is it still a good deal to purchase it and fix or should I look elsewhere? I've read it could be as simple as the brake light switch. If this is in the wrong place I apologize I'm new.

Electrical stuff like that would never stop me from buying. It comes down to a wiring or switch issue. Worst case fuse block. You can solder leads to a light bulb and test the circuit or buy a very inexpensive meter at Harbor Freight that will be more than adequate to diagnose just about anything on truck.
All is rather inexpensive- just time to find problem.
Now, if it was a newer vehicle with a bunch of computers ($$$$$) inside, that's a different story.

 

[603hellmutt]

Okay fair enough, now comes the real question how much do you think the truck is worth?
It's in great condition cosmetically rubber is at 100% and it runs like a dream, better then my old m977

 

[98G]

If you get it, replace that push button switch with a 3 lever switch. Those push button switches are known to fail and take a bunch of stuff with them.

The brake lights are actuated by the airsystem when the brakes are applied. As stated above, it may be a bad ground or a bad switch. Also as stated above, it's almost certainly a trivial fix.

 

[603hellmutt]

Is the switch swap simple? I'm used to the flip switches these buttons seemed pointless. Do you think $10k is to much for the truck? Has about 50 hours on it since refurbishment.

 

[mdemars03]

The switch swap is extremely simple. Like 98G stated swap the button style switch for a three lever switch. It is a very simple about 5 minutes job. If it is the brake light switch it is a quick fix as well. The brake light switch is on the frame rail on the driverss side behind the fuel tank. You will see two air lines and two wires going into it. It is held on the truck by 2 bolts. All the checks from the switches to grounds to loose connections are all very quick checks.

I have also read a few threads here about the button style switch being the culprit to vehicle fires. I don't know if there is a newer style button switch that got rid of that, but it was an issue I have read about. The three lever style switch is safe, simple, and works great.

 

[mdemars03]

As far as cost of a truck I am only on my second truck so I don't have the expertise in pricing. However, 98G has that knowledge. I sold one I had issues with and bought my current one from him and couldn't be happier.

 

[603hellmutt]

I appreciate the info, ill contact 98g and see if that is a fair price. I found quite a few of the flip style switches that I will buy if end up with this truck.

 

[mdemars03]

Cool. Also like we said check all the connections. Loose connections or bad grounds can cause all kinds of trouble on all kinds of things.

 

[Tinstar]

When/if your checking connections, apply a dab of dielectric grease while you have the connection apart.

Really helps to prevent other problems down the road.

 

[Tinstar]

What the others have said.
Toss the button switch and get the lever.

If you search the old threads, you will find they are a cause of fires and meltdowns.

 

[gochenour799]

Can you please tell me where the brake switch on a m931 is . I'm having brake light issue. Tail lights are good .turn light is good .brake bulbs are good .

 

[M35A2-AZ]

Can you please tell me where the brake switch on a m931 is . I'm having brake light issue. Tail lights are good .turn light is good .brake bulbs are good .

It is on the drivers side of the inside of the frame about half way back. I think just past the transfer case.

 

[The HUlk]

Can you please tell me where the brake switch on a m931 is . I'm having brake light issue. Tail lights are good .turn light is good .brake bulbs are good .

As was mentioned mounted in the inside of the drivers side frame rail about even with the rear of the fuel tank. Disconnect it and jump the wires together. If the brake lights come on then you have found the problem.