99 Land Cruiser 15amp gauge fuse blows when put in reverse

[Loves2na]

Hey folks! So I went on a beer and steak run this past weekend and now I have a problem blowing the 15amp fuse for the gauge cluster every time I put it in reverse..I believe it started blowing after a good mile or two of driving through some pretty bad wash boards from the trail..I check the things I think may be the culprit..possible water in my reverse lights, my trailer lights, and all the main grounds from the main battery as well as my aux battery..please help if anyone has experience or insight with my situation..ps I searched and I can't find my answer here or anywhere online..thanks in advance!

 

[SkidMarcus]

Definitely sounds like a grounding issue or some wires are touching each other inappropriately.

 

[NickSonoma]

Does it pop the fuse immediately once it is in reverse?

Does it pop when other dash lights(center diff/od off) are activated or is it only reverse?

Do you have a camera or sensors when in reverse? Is that circuit pulling more amperage than a factory


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don’t do these things, because your 23 year old truck that you drive into the abyss, that is a zombie apocalypse contender can’t handle these types of repairs or diagnostics:

1) give it all a chance to dry and see if it fixes itself.

2) if the fuse blows immediately, disconnect the battery from the vehicle. run some speaker wire from the battery to the reverse lights for 1 second. If the fuse blows, you know that circuit is the issue. If the circuit is a daisy chain set up, you can start at the light closest to the battery and disconnect the lights behind it. If the fuse doesn’t blow reconnect everything and move one light down, repeat. Once the fuse blows, you know the problem is between a those two bulbs. Temporarily run speaker wire from the last socket that worked to the first one that didn’t, reconnect the battery, try to blow the fuse. If it doesn’t blow, you know where your problem is. When you have a second, properly install a wire.

3) your truck will probably explode if you do this. Put a 20A fuse in there for a second and see if it works. If it works, you know that the issue probably won’t be super obvious. It could be a loose connection or a corrosion issue that passes the eye test.

P.S. I have used these techniques. They get a bad name because some idiots end up with an entire vehicle made out of temporary hacks. You can fix a vacuum leak with a piece of gum, or you can upsize one fuse. You don’t want a car with both. Yes certified mechanics will warn you that you should pay them $90/hour because you have a 0.05% chance of burning a $80 sensor. There are better ways to do this, these are quick and effective. The negative stories from these fixes are a lot like witness’ descriptions of cow tipping. When I hear, “My cousin’s friend’s uncle put a 20A fuse in and his ECU was fried as a result.” I hear, “one time a guy on YouTube replaced a 15A with a 120A circuit breaker on a car with a flood/salvage title.”

all factory parts on our trucks have exceeded their intended life span. You can’t shorten their lifespan by making them work after they stop working. Just make sure the hack is isolated to just that circuit.

 

[Loves2na]

Definitely sounds like a grounding issue or some wires are touching each other inappropriately.

Which grounds aside from the engine bay should I look at?

 

[Loves2na]

Does it pop the fuse immediately once it is in reverse?

Does it pop when other dash lights(center diff/od off) are activated or is it only reverse?

Do you have a camera or sensors when in reverse? Is that circuit pulling more amperage than a factory


xxxxxxxx ccxxxxxxxxxxxxxxxxxxxxx
don’t do these things, because your 23 year old truck that you drive into the abyss, that is a zombie apocalypse contender can’t handle these types of repairs or diagnostics:

1) give it all a chance to dry and see if it fixes itself.

2) if the fuse blows immediately, disconnect the battery from the vehicle. run some speaker wire from the battery to the reverse lights for 1 second. If the fuse blows, you know that circuit is the issue. If the circuit is a daisy chain set up, you can start at the light closest to the battery and disconnect the lights behind it. If the fuse doesn’t blow reconnect everything and move one light down, repeat. Once the fuse blows, you know the problem is between a those two bulbs. Temporarily run speaker wire from the last socket that worked to the first one that didn’t, reconnect the battery, try to blow the fuse. If it doesn’t blow, you know where your problem is. When you have a second, properly install a wire.

3) your truck will probably explode if you do this. Put a 20A fuse in there for a second and see if it works. If it works, you know that the issue probably won’t be super obvious. It could be a loose connection or a corrosion issue that passes the eye test.

P.S. I have used these techniques. They get a bad name because some idiots end up with an entire vehicle made out of temporary hacks. You can fix a vacuum leak with a piece of gum, or you can upsize one fuse. You don’t want a car with both. Yes certified mechanics will warn you that you should pay them $90/hour because you have a 0.05% chance of burning a $80 sensor. There are better ways to do this, these are quick and effective. The negative stories from these fixes are a lot like witness’ descriptions of cow tipping. When I hear, “My cousin’s friend’s uncle put a 20A fuse in and his ECU was fried as a result.” I hear, “one time a guy on YouTube replaced a 15A with a 120A circuit breaker on a car with a flood/salvage title.”

all factory parts on our trucks have exceeded their intended life span. You can’t shorten their lifespan by making them work after they stop working. Just make sure the hack is isolated to just that circuit.

It started after some wash boards I went through and yes it immediately pops when I put it in reverse, without any other dash lights on, it'll pop. So mainly when in reverse. I have a backup camera tapped into the rear tail lights, but I've soldered the taps and electrical taped them nicely. I've had my camera for 2 years now and been out on trails, been through water and stupid wash boards without any issues. I've also checked them to see if there's any water or moisture and nothing.

 

[NickSonoma]

It started after some wash boards I went through and yes it immediately pops when I put it in reverse, without any other dash lights on, it'll pop. So mainly when in reverse. I have a backup camera tapped into the rear tail lights, but I've soldered the taps and electrical taped them nicely. I've had my camera for 2 years now and been out on trails, been through water and stupid wash boards without any issues. I've also checked them to see if there's any water or moisture and nothing.

The reason I asked about the camera is because you may have increased the current draw on the circuit. So you may be able to justifiably put a larger fuse in, and not feel like you’re a bad person.

The fact you defended the quality of the install on the camera makes me think that the camera has something to do with it. Not because of anything you did, but because the repair gods really be like that.

 

[NickSonoma]

Which grounds aside from the engine bay should I look at?

Ground fault issue. When grounds are weak you end up with a weak circuit not an excessively strong circuit. When people mention ground/grounding in relation to blown fuses, they typically mean that there is a current carrying wire that has lost all of its insulation and has contacted a large enough piece of conductive material to draw more current than the fuse can handle.

it could be a wire that shook loose from a bulb socket, or it could be a wire that is in a place that you will never find. You can tell roughly where the problem is by understanding the wiring, then cutting segments off until the fuse stops blowing.

 

[Loves2na]

Ground fault issue. When grounds are weak you end up with a weak circuit not an excessively strong circuit. When people mention ground/grounding in relation to blown fuses, they typically mean that there is a current carrying wire that has lost all of its insulation and has contacted a large enough piece of conductive material to draw more current than the fuse can handle.

it could be a wire that shook loose from a bulb socket, or it could be a wire that is in a place that you will never find. You can tell roughly where the problem is by understanding the wiring, then cutting segments off until the fuse stops blowing.

I really appreciate the educational information sir! Ima take a look into the camera cables and get back to ya!

 

[NickSonoma]

I just remembered that this is a safety feature that keeps you from driving without tail lights in the dark, but still lets you limp home. You may just have a blown bulb and the circuit is designed to blow to alert you to a problem. You have my thoughts and prayers that it’s that simple.

 

[ClassyJalopy]

I am facing a similar issue. I just added a rear camera and an LED lamp to my rear light circuit. Both turned on just fine on the test run, when I had both reverse lamp bulbs removed from the standard location.

When I went to put the bulbs back in the standard tail lamp, all the reverse lights and the backup camera went dark. Curiously enough it also caused the dashboard cluster lights to turn off too.
Based on the discussion on this thread, I am wondering if my reverse circuit is overloaded and if I should try a 20amp fuse instead of the 15a one??

 

[NickSonoma]

I am facing a similar issue. I just added a rear camera and an LED lamp to my rear light circuit. Both turned on just fine on the test run, when I had both reverse lamp bulbs removed from the standard location.

When I went to put the bulbs back in the standard tail lamp, all the reverse lights and the backup camera went dark. Curiously enough it also caused the dashboard cluster lights to turn off too.
Based on the discussion on this thread, I am wondering if my reverse circuit is overloaded and if I should try a 20amp fuse instead of the 15a one??

LED lamp can be one small LED attached to the camera, or a light bar that can be observed from space.

You can always diagnose the problem by putting it back to stock and seeing if it works. You can then add one item at a time and see if it works when just one aftermarket part is supplied. The right answer is to run a new power wire and attach it to a relay that is triggered by the reverse lights. A half ass combination would be to tap into the trailer connector power line if you never use it. It’s already made to power multiple lights.

“Upgrading” the fuse on incandescent lights is a poor idea. I am the first person to drop a larger fuse in to get a few more years out of nearly every other part, but incandescent light bulbs like the ones in our stock lights produce a lot of heat. The fuse prevents them from drawing too much. Upgrading the fuse could possibly expose your plastic light housing to unexpected levels of heat.

(14v)x(10amps)=140 watts
(14v)x(15amps)=210 watts

I don’t know how to translate that to heat, but as you can see 5 additional potential amps can increase the wattage by a tad bit. Enough to necessitate a larger wire. 12 Volt Wiring: Wire Gauge to Amps | - http://www.offroaders.com/technical/12-volt-wiring-tech-gauge-to-amps/

 

[ClassyJalopy]

This is an @ayutype question but do the dashboard dials and reverse lamp share a fuse? All if my tail lamps, turn signals and even warning lights in the dash work just the dials, their backlights and the reverse lamps are out!