gauge lights and tail lights dont come on???

[brakers50]

hey guys, i need some help if its not too much to ask. i bought a 1991 240sx (coupe) a few weeks ago. the previous owner told me that the gauge lights and the tail lights dont come on when you turn on the head lights like they are suppose to. for more than a week, ive been searching for the problem with no luck. its my first 240 so i dont know much about them. do you have any suggestions as to what the problem is and how to fix it???? the all wire harnesses for the original radio had been cut. all the fuses are ok. and the bulbs seem to be fine. thanks a lot

[boost_creep]

i had this same problem one night,but it turned out to be the taillight fuse in the driverside kick panel.

[masticatingcow]

It's likely that the radio harness grounded out when it was cut. Arcing a current on the interior curcuit will knoc out either the TCU or the fuseable link under the hood.

Try the TCU. It's under the regular fuse box behind the driver's side kick panel. If you have a friend with a 240sx, borrow theirs and swap them. If it fixes your problem, they can be had for very cheap at just about any junkyard.

If not, then it's probably the fuseable link. Download a FSM and if you can read wiring diagrams (trust me, it's not THAT hard) you'll be able to find it.

[brakers50]

ok. but what it the TCU??? and i heard something about illumination wires. do they have to be connected? cus they were cut as well and never reconnected. if they do need to be connected, what goes where??

[masticatingcow]

The TCU is a white box found right below the in-cabin fuse panel. You'll need to remove the entire kick panel to get at it. I've installed several decks in my car and never have had any issues with illumination circutry. All the dash illumination is controlled via a printed ciruit on the back of the cluster. There are no wires to speak of, save for those in the wire harness, which I doubt was tampered with.

[brakers50]

thanks alot guys for helping! ok, i looked for and found the tcu. i dont think that is the problem though. i took a electric tester and found that there was no current running to the two of the wires on the switch that pops up and down the front head lights. all the other wires had a current running to them. sooo, my guess it that one of the wires has to be a power and the other ground. the wires are blue/red and red/yellow. i found those same color wires among the cut wires from the harness. only there are 2 of each wire behind the deck.

[hondahunter180]

my instrument lights stopped working and it did trun out to be the TCU. there are a lot of problems with this when changing the radio.

[brakers50]

okay. everyone keeps saying tcu. so i will go pick one up tommarrow. just one quick question. what does the TCU do? what is it for? and thanks alot guys for your help up until now.

[FliMSiCaL]

heh....what they mean by illumination is that there is 1 particular wire in the radio harness that controls radio illumination, and if hits the frame, out go ur tails and cluster lights.. tape up all the cut wires so they don't short anymore and go hunt the fuse it blew, its somewhere in one of the 3 fuse boxes. I'ts happened to me before, but it doesn't always blow the same fuse...