Mashashin

Hey guys, new to this forum but not to this truck. I've been a member over at toyota nation for a little bit under a year now and am getting fed up with that place, seems like it takes forever to get a response or even get one at all. No disrespect to the people there, they know their stuff though.

On to my problem. I have a 1991 Pickup with a 22RE 5 speed manual 4x4 with a 6in sky jacker lift kit, 31x10.5 R15 cooper discoverer tires on AR wheels, and a semi cancerous bed. The 15 amp fuse under the dash for the front marker lights, dash cluster lights, and climate control lights keeps burning out. I've been through 11 15 amp fuses in the past month and a half. I was told there is most likely a solenoid going out? If this may be true, where would this solenoid or relay be located?

Thanks guys, looking forward to hearing back from you!

Levinz11

Sucks that you haven't gotten an answer yet. I wish I could help you dude.

rworegon

Check the wires in those circuits for a worn chafed spot that is shorting out causing the fuse to pop.

Under what conditions does the fuse pop? A bumpy road where wires are getting bounced around?

Mashashin

it's completely random when it happens. With the last pack of fuses I bought from my work I went from replacing the fuse, driving 2 miles on nice smoothish city roads toward the interstate on ramp and it blew while waiting to turn at the light for the on ramp. I replaced it when I got home and drove to work the next day, had it blow again around 3 or 4 miles into my trip to work ( it's only 6 miles to work ). I replaced it when I got there and I haven't had this one pop yet because I haven't had to turn on my lights to drive at the butt crack of dawn or when it's dark. I'll check the fuse panel for a rubbed wire in the morning

rworegon

Check the wires that feed the lights too. Only happens when the lights are on?

Mashashin

Yeah it'll only happen when the lights are on

rworegon

Ok....focus on the fuse, wires, and the head light relay. The head light relay may be what your other folks are calling a solenoid.

Here is the FSM for the '93 that may help. Your '91 will be similar enough most likely.

http://www.ncttora.com/fsm/1993/body.../4lighting.pdf
http://www.ncttora.com/fsm/1993/index.html

Mashashin

Could that relay cause that to happen? If so I could find a relay at auto zone to replace it correct?

rworegon

They may have the relay, but often they are a dealer part.

Take a look at the troubleshooting section of the first link in post 7.....it should help.

James Woods

iTrader: (1)

The headlight relay is not on the same circuit as the fuse you keep popping, there is a tail light relay, but that is before the fuse so your problem is most likely after the fuse, either one of your light sockets or some wiring that is grounding.

I had this same problem on my first car a 1967 Caprice and the problem was the windshield was leaking onto the back of the cluster, when I would dim the dash lights all the way, it wouldn't blow.









Good luck.

Hadmatt54

First, tailight relays have the least complicated construction of any relays and they seldom go bad, if you have a spare then yes changing it is a quick step in troubleshooting your problem. If you don't have a spare then you will be probably be wasting your money! You have probably got a partial short in your wiring harness. It's not a dead short or it would blow as soon as you turned on your lights, it's partial because the problem does not occur until the vehicle is moving, causing the short to happen. Your tail light circuit controls the front parking lights and rear tailights, licence plate lights, marker lights, dash lights, lights in the radio, glove box, gear shift (if auto)etc. It also feeds into the integration relay, so does your turn signals, your gauge feed, drivers side dome light switch, etc. and though it is rare the integration relay does go bad. One of my co-workers had to replace one on his 90's truck, but I'll have to ask him what exactly his problem was. So many circuits feed into the integration relay, his problem may have been totally different than yours. Have you made any changes to your wiring lately? Problem with this circuit is that you cannot do a continuity check on the circuit using a VOM without removing all of the bulbs, because the bulbs have a low resistance and your check will always show a short to ground. You've got to isolate portions of the circuit to solve the problem. If you haven't been into the wiring in the dash adding accessories to your truck, then the most common cause might be a short in your rear harness. That harness is more open to the elements and debris from going off road. If your fuse will hold for a bit when the truck is not moving check to see if all of the lights in the circuit are working at night. If you have one out, figure out why! If nothing is obvious, then under the passenger seat there should be a connector that connects the cab/front harness to the rear harness, unplug it put in a new fuse and go for a drive to see if the fuse blows, if it doesn't blow then you know your problem is on the rear. A word of caution, once you unplug the rear harness you won't have any brake lights, signals or taillights, so do this test some place where you are not around traffic or the police. If your problem is the rear harness, then you will have to open it up and look for a short.
If the problem is not on the rear, then unplug the connector from the reostat that dims the dash lights. The reostat controls the resistance in the ground circuit, if you unplug this you isolate all of the dash lights, with the rear unplugged, and the reostat unplugged the only lights in the circuit are the front parking lights, the glove box light (if you have one) and the clock illumination. Now try that drive again.
This is not any easy short to find, you may have to work at it awhile.
Good Luck!

Mashashin

Wow you guys are extremely helpful. I really appreciate it. I'll dig in and hopefully get this figured out this afternoon.

rworegon

Good catch, James. I had not taken the time to look at the wiring diagram.....my bad. Note to self: next time, rworegon, before answering incorrectly...

Terrys87

iTrader: (1)

Alot of your problem sounds like the ENG fuse. I may be wrong. If it is, I went thru the same problem and what I found is the plug to the reverse lights if I recall right, it is on the drivers side. There is a protective tube over the wires, but it can slide back a little and let the wires rub on tranny, thus causing a short. On Page 14, Post 343 I have a pictrue of it on my 88 build.
I show it wrapped up in electrical tape.

Mashashin

Oh you may have saved me a lot of trouble. There are wires rubbing down there. I will check that right now

Terrys87

iTrader: (1)

Is it your ENG Fuse? Seems like when I had that problem, the only guage that worked was my speedo, and nothing else. It has been a while, but I do remember doing alot of troubleshooting and was surprised tha it was only a few threads on it and they were vague.

Terrys87

iTrader: (1)

Where my pointer finger is slide that tube/cover back and it will be right at the plug, if this is your problem. It wont have much expsoed wire, but it doesnt take much. Just enough to make contact with tranny.

swampfox

,,,,,

Mashashin

Now that I think about it... One of my license plate lights got ripped off a while back... I'll be replacing it this afternoon with an aftermarket one away since I have an aftermarket bumper

Hadmatt54

Terrys87 wrote:
Terry: I had a similiar problem on my truck last summer...it wasn't bare wires, the reverse light switch was shorting blowing my engine fuse.

Mashashin's problem is his taillight circuit!