Lights shutting off if I keep either highbeams or bright dash on

[Enforced_Leo44]

As the title says, in my recently acquired M998, all the lights shut off for about 15sec or so if I turn on the highbeams or the dash light on the bright settings for long enough
If I turn them both on at the same time, that "long enough" shortens to less than a minute

What could this be caused by? I did a rapid research but haven't found anything talking about this
Thanks in advance, any advice would be very appreciated!

 

[Mogman]

There is a circuit breaker in the light switch, you must be overloading the breaker or it is weak.
Have the headlights been replaced, or was it in civilian hands before you bought it?

 

[kendelrio]

Check for a short to ground on the power side.

 

[Enforced_Leo44]

There is a circuit breaker in the light switch, you must be overloading the breaker or it is weak.
Have the headlights been replaced, or was it in civilian hands before you bought it?

Thanks for the reply,
I think that headlights have indeed been replaced, with some Wagner ones, it was in civiliand hands but as far as I know the guy who had it before knows what he's doing, he restored many military vehicles and if anything, I'm almost certain that he didn't screw up on swapping headlights with some wrong voltage ones, if that's what you mean

Also, I could try to install a new light switch and see if that fixes anything, a friend of mine has a "new" one laying around

 

[Mogman]

I would look at the back of those headlights and see if they are 12V if he re-wired the headlights for 12V that is your problem, the 12V lights pull around twice the amps as the 24V ones which would overload the breaker.

 

[Enforced_Leo44]

I would look at the back of those headlights and see if they are 12V if he re-wired the headlights for 12V that is your problem, the 12V lights pull around twice the amps as the 24V ones which would overload the breaker.

Oh right I see, I remember asking him about the headlights and he said that those were some 24v military surplus, but I'm gonna check myself anyways so thanks!

If the headlights turn out to be 12v, I'm gonna need to re-re-wire everything back to its original place, hoping that the previous owner didn't put up a jungle of jumper wires to compensate for that

 

[Enforced_Leo44]

I would look at the back of those headlights and see if they are 12V if he re-wired the headlights for 12V that is your problem, the 12V lights pull around twice the amps as the 24V ones which would overload the breaker.

After a intense research aka unscrewing the 3 screws holding the headlight on and reading 60w/80w 28v on the back of said headlight, I can confirm that the headlights are meant for 24v systems

The next step would be to find and install a new or NOS light switch, right?

 

[springer1981]

The next step would be to find and install a new or NOS light switch, right?

Any switch to test with other than yours. You can simply unscrew the harness from the back and screw it into a test switch, doesn't need to be mounted to test.

 

[springer1981]

Also, you should check all your light bulbs to make sure they are 28v. What is tripping the breaker is the total current used to power all lights, marker lights, tail lights, etc. When you turn on the high beams it puts you over the amount required to trip the breaker. Since the head lights are correct other bulbs may be causing an increased draw and tripping the breaker.

 

[Enforced_Leo44]

Also, you should check all your light bulbs to make sure they are 28v. What is tripping the breaker is the total current used to power all lights, marker lights, tail lights, etc. When you turn on the high beams it puts you over the amount required to trip the breaker. Since the head lights are correct other bulbs may be causing an increased draw and tripping the breaker.

That is also true, I'll do a total check as soon as possible, headlights and dash lights are 28v for sure, blinkers, stop and tail lights as well as markers have to be checked, thanks for the input

 

[Mogman]

After a intense research aka unscrewing the 3 screws holding the headlight on and reading 60w/80w 28v on the back of said headlight, I can confirm that the headlights are meant for 24v systems

The next step would be to find and install a new or NOS light switch, right?

Since it is obviously a serious short (breaker tripping as soon as the lights are turned on) substituting the light switch would seem to be a logical step.

 

[springer1981]

Since it is obviously a serious short (breaker tripping as soon as the lights are turned on) substituting the light switch would seem to be a logical step.

I guess I missed the part where he said it happens as soon as they are turned on. I got the impression it's based on current draw and not immediately after it is turned on.

 

[Mogman]

I guess I missed the part where he said it happens as soon as they are turned on. I got the impression it's based on current draw and not immediately after it is turned on.

No they are not tripping as soon as they are turned on, it takes a while and must be on high beam, sorry if I flubbed that up.
It is possible the breaker in his switch is just weak.

 

[Enforced_Leo44]

No they are not tripping as soon as they are turned on, it takes a while and must be on high beam, sorry if I flubbed that up.
It is possible the breaker in his switch is just weak.

Yes exactly, this is what I was thinking, the breaker got weaker as it aged and now it can't sustain as much draw as it should per spec