I have a 1987 toyota 4runner and no running lights or dash lights . The tail light fuse is ok but still no dash lights or running tail lights break lights light up fine.

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check this fuse too..
The dash illumination lights run off of the TAIL fuse. Wierd I know!!
also a bad dimmer switch could very well be the culprit.

The tail and marker lights and Instrument lights are on the same circuit so both will go out if the fuse for this circuit blows. If fuse continues to fail, check the tail light or marker globes, including the globes for the number plate, for a globe that may have an internal short causing the fault and replace as necessary. As you have already checked the wiring near the light fittings for any chafed wires that could be shorting to the body causing the fault, then a closer inspection of the wires inside all the light assemblies for any shorts may be needed.

It could also be that the instrument dimmer control has failed and is causing the fault. The electronic bits inside the dimmer control for these lights sometimes go faulty. Try disconnecting the connecting plug on the rear of the dimmer control and checking if fuse still blows. If fuse continues to fail, then the fault in the tail and marker lights circuit.

Remove all the tail, number plate and running light globes from the light assemblies and leave the instrument dimmer control disconnected and check if fuse still blows.

Disconnect the plug near each of the light assemblies to see if any of the individual assemblies is causing the fault. With all light assemblies disconnected and fuse continues to fail, then the fault must be in the main wiring loom some where.

If you have a Multimeter, it could be used to determine which light assembly has a fault between the lamp supply and earth connection.

you say you checked the fuse so I ASSUME its good? and getting power? there is a Tail Light Relay. If the relay is good, then that fuse (tail light) will have power. If it does not, then check the relay, maybe rap on it. The relay is round up under the dash, left kick panel area. just below where the tail light fuse is.

This sounds more like a dimmer switch problem but could be a fuse they are located
drivers side kick panel under the dash. I think they were mini fuses for this vehicle.

check tail , brake and courtesy fuses , in engine compartment fuse box , and driver side fuse box under dash

Check the tail light failure sensor. Located in the driver's side kick panel fuse box. ~Rick89GTS

usually when dash lites are out the tail or break lites are out too check both. Im thinkin a fuse

check for bloown fuse