we have a 2008 suburban at work. It blows fuses that kill both tail lights and license plate light. It has been taken in to a reputable shop repeatedly and repaired. we have experience with several shops and the latest says it is in the fuse panel, since repaired but now unrepaired.As a patch, is there a blade fuse that actually acts as a circuit breaker, preferably auto resetting? This is not a good or permanent fix, but anything is better than nothing. Anybody know of a classic problem that this fits? Thanks!
2008 suburban repeatedly blows fuses - fix is ????
- Thread starter bmwjohn
- Start date
- Status
You may have an intermittent open ground that is telling the alternator to go to maximum voltage and amperage for very short periods of time. If that's true your vehicle will start frying more expensive stuff in the future. Open grounds sometimes start slow and get worse as you drive around, and never fix themselves.
If you start adding ground straps between stuff like the engine block and chassis, the alternator housing and the engine block, the a/c compressor and the engine block, the engine block and the negative side of the battery and the problem goes away then you have found what's causing your problem, just not where exactly it's happening.
These high voltage/amperage events that do things like fry the fuse block usually start by hitting a circuit like the fuel pump, headlights or the a/c. For some mechanics this kind of stuff is difficult when they usually spend their time changing a timing belt or replacing spark plugs. Fixing an electrical problem like this does not show much for the work involved and sometimes makes billing the customer for the time spent can be an interesting experience. So, instead they start changing parts. That way the customer can see what's going on and the mechanic can at least show that he/she was doing something.
Try the ground straps and test along the way with your handy multi-meter between these devices. Just make sure the ground straps hit clean, bare, just prepared surfaces. Your local boating supply store has really good ground straps and the spray stuff you can use to seal everything after making the connections.
If you start adding ground straps between stuff like the engine block and chassis, the alternator housing and the engine block, the a/c compressor and the engine block, the engine block and the negative side of the battery and the problem goes away then you have found what's causing your problem, just not where exactly it's happening.
These high voltage/amperage events that do things like fry the fuse block usually start by hitting a circuit like the fuel pump, headlights or the a/c. For some mechanics this kind of stuff is difficult when they usually spend their time changing a timing belt or replacing spark plugs. Fixing an electrical problem like this does not show much for the work involved and sometimes makes billing the customer for the time spent can be an interesting experience. So, instead they start changing parts. That way the customer can see what's going on and the mechanic can at least show that he/she was doing something.
Try the ground straps and test along the way with your handy multi-meter between these devices. Just make sure the ground straps hit clean, bare, just prepared surfaces. Your local boating supply store has really good ground straps and the spray stuff you can use to seal everything after making the connections.
Look at the parking brake ratchet under the dash. I have fixed various electrical problems by repairing chaffed wires running near some very sharp edges on the ratchet.
A loose or rusted wire does NOT cause higher amp draw. less conductivity WILL cause a wire to heat up near the bad connection. The heat can also migrate up the copper to other connections usually ending in failure. Perception of higher current draw is due to feeling the hot wire.
I would check for chafed wire as was suggested. A chafed wire that contacts anything metal will cause higher amp draw and blow a fuse. Also a bad connection in the fuse receptacle itself can heat up and melt the fuse. Look at the receptacle for discoloration from heat. The fuse leg may also show heat damage if this is the case. You can use one of those IR temperature gauges to find hot spots
Water or contaminants in the light bulb sockets is something to check as well... Pull the bulbs and look at them for contaminants.
The possibility the alternator is over voltage could be seen on amp guage and imo not likely.
I would check for chafed wire as was suggested. A chafed wire that contacts anything metal will cause higher amp draw and blow a fuse. Also a bad connection in the fuse receptacle itself can heat up and melt the fuse. Look at the receptacle for discoloration from heat. The fuse leg may also show heat damage if this is the case. You can use one of those IR temperature gauges to find hot spots
Water or contaminants in the light bulb sockets is something to check as well... Pull the bulbs and look at them for contaminants.
The possibility the alternator is over voltage could be seen on amp guage and imo not likely.
Last edited:
The front corner lights would also be on the same circuit. So consider the possibility of shorts up there. Turn the lights on and go around to each light to take apart and poke and prod stuff and see if you can make the fuse blow while you are watching what did it.
Also if there's any unofficial wiring for the connection of trailer lights, that would be highly suspect.
Also if there's any unofficial wiring for the connection of trailer lights, that would be highly suspect.
Last edited:
There are, in fact, circuit breakers that fit blade fuse sockets. You might have to go to an electronics supply business or online because automotive shops probably won't carry them.
If you do want to look at a Bricks & Mortar local store, try motorcycle or marine versus car/truck as they are more likely to use circuit breakers exclusively and no fuses at all.
Check Littlefuse or Bussmann manufacture; and apparently RockAuto stocks them.
Your go-to online vendors for anything electronic are Digi-Key, Mouser, Jameco, etc
Note that the above is FYI; the proper solution is to find the reason and fix that.
If you do want to look at a Bricks & Mortar local store, try motorcycle or marine versus car/truck as they are more likely to use circuit breakers exclusively and no fuses at all.
Check Littlefuse or Bussmann manufacture; and apparently RockAuto stocks them.
Your go-to online vendors for anything electronic are Digi-Key, Mouser, Jameco, etc
Note that the above is FYI; the proper solution is to find the reason and fix that.
I would suggest you buy some Load Pro leads for a multi meter ,,works with any multi meter ( you can buy the snap on version if you want but it just costs more ) .
you can watch a few videos on youtube on how to use .. bt basically you hook up the meter at one of the bulb locations and can push a button and load the circuit..if the voltage drops you know you problem is along those wires of the circuit .. and you can also tell if it is on the ground side or power side ..view a few videos and see if you would like to get it ( around 60 ) or buy a power probe fox and hound set up .again check some videos for tracing a short with a fox and hound ..Brians mobile one has a good one
you can watch a few videos on youtube on how to use .. bt basically you hook up the meter at one of the bulb locations and can push a button and load the circuit..if the voltage drops you know you problem is along those wires of the circuit .. and you can also tell if it is on the ground side or power side ..view a few videos and see if you would like to get it ( around 60 ) or buy a power probe fox and hound set up .again check some videos for tracing a short with a fox and hound ..Brians mobile one has a good one
- Status
