Headlights relay blown?

[dbh2005]

Hi all, I just bought an 01 Tundra and am new to this forum. My problem is, I installed my remote starter tonight and made a mistake. I didn't realize that the headlights used a negative pulse and when I hooked up my starter (which by default uses a positive pulse) to them, I blew out my headlights and dash lights.

All fuses are fine, and the day-time running lights still work.

Could I have blown a relay with this 12v surge? If so, any ideas on which one(s) and how to test them?

Or any other ideas on what I could have blown (inline fuse, etc)?

Thanks for the help!

[UnSub]

Originally Posted by dbh2005

Hi all, I just bought an 01 Tundra and am new to this forum. My problem is, I installed my remote starter tonight and made a mistake. I didn't realize that the headlights used a negative pulse and when I hooked up my starter (which by default uses a positive pulse) to them, I blew out my headlights and dash lights.

All fuses are fine, and the day-time running lights still work.

Could I have blown a relay with this 12v surge? If so, any ideas on which one(s) and how to test them?

Or any other ideas on what I could have blown (inline fuse, etc)?

Thanks for the help!

I have attached 2 files showing you the relay locations and the schematic with DRL. You can tell the pin numbers of the relay shown on the schematics by looking up the relays on the relay locacation drawings. The "head relay" has to be O.K. because your DRL work. The DRL relay is located right next to it on the drivers side under the hood and is suspect. The resistors are used for the DRL to be on and the DRL relay is used to bypass the resistors and cause the headlights to come on at full output (either bright or dim). You should check the 7.5 amp DRL fuse first, then the DRL relay. I know this sounds wrong but trust me, this is the way it works. There is a print out included with the schematic that will take you step by step through how it works. If this does not solve the problem, let me know and I will help you look at the other areas of possibilities. There are diodes in the circuit but I did not try to locate them yet.
Also, there is a DRL RELAY (MAIN) in the cab. You can find it in the location drawings and it is a part of the circuit but I would look at the one under the hood first. I would check the DRL fuse and if good pull the DRL relay and read for resistance accross its coil. You can also jumper pin 2 to 1 on the DRL relay socket, with the DRL lite up and see if they go to full brillance (with the relay out). Good luck.

[dbh2005]

Thanks for the info. I'll give it a try tonight and will let you know. I appreciate the help!

[UnSub]

Earlier I did not have time to look at the dash light part of your problem. The 2 problems may or may not be caused by the same component. You probably already cheched but make sure your rheostat did not get bumped into the full dim position. The 15 amp tail or 5 amp cargo fuse both feed the integration relay so I would check them. The light control switch and the integration relay are both in common to the 2 circuits. You could check the appropriate pins if you can get to them at the integration relay. I did not look at how hard it would be to get to but if memory serves me, it is behind the fuse panel located on the lower dash. Again, good luck.
The schematic is attched

[dbh2005]

Originally Posted by hkiser

I would check the DRL fuse and if good pull the DRL relay and read for resistance accross its coil. You can also jumper pin 2 to 1 on the DRL relay socket, with the DRL lite up and see if they go to full brillance (with the relay out). Good luck.

Ok, I checked the DRL fuse and it is good. Next I pulled the DRL relay and wasn't sure how to read for resistance across its coil (sorry I'm new to the electrical side of things) but I did connect pin 2 to 1 and the DRL then went to full brillance. Does this mean the relay is bad?

[UnSub]

Originally Posted by dbh2005

Ok, I checked the DRL fuse and it is good. Next I pulled the DRL relay and wasn't sure how to read for resistance across its coil (sorry I'm new to the electrical side of things) but I did connect pin 2 to 1 and the DRL then went to full brillance. Does this mean the relay is bad?

Either the relay is bad or the circuit that pulls it in is bad. The easiest thing to do now is to either change the relay or better yet, borrow one with the same part numner from another location. Check the "head" relay, the fog light relay or the pwr relay to see if they have the same part number on them.

If the head relay is identical, switch it with the DRL relay. If the symptoms are the same, the relay is good. If the DRLights will not work now, the relay is bad. (this relay is the one that was in the DRL socket but is now in the head socket)

If the head relay was not the same as the DRL relay, see if either the fog light or pwr outlet relay is the same as the DRL relay. If so, pull out the DRL relay and just set it aside. Remove the other relay that matches, and insert it in the socket you remove the DRL relay from, turn the truck and lights on and see if the problem is resolved. If so, you will get off for the price of a new relay. If not fixed, you will need to get a voltmeter or test light to test further. Let me know and I will be happy to try and help further.

[dbh2005]

Ok, I ended up taking it in to Toyota to find the problem for me and they came back and said that the headlight switch and rheostat got fried. He said that he checked the circuits on either side of the switches and they seemed fine, so they're best guess is that it's just the switch and rheostat.

Question is, how difficult would these be to replace? Dealership wants $265 to install, is this something I could do easily myself?


Thanks for the help!

[UnSub]

Originally Posted by dbh2005

Ok, I ended up taking it in to Toyota to find the problem for me and they came back and said that the headlight switch and rheostat got fried. He said that he checked the circuits on either side of the switches and they seemed fine, so they're best guess is that it's just the switch and rheostat.

Question is, how difficult would these be to replace? Dealership wants $265 to install, is this something I could do easily myself?


Thanks for the help!

I was afraid we were going to end up at the headlight switch. I have an 03 manual and it looks easy to change both parts. I assume yours is the same. I have never changed these parts but if it were my truck I would give it a try. It looks like the switch is only held on by a couple of screws once you get the column cover off. The cover is in a couple of parts. You can see one screw on the bottom and the others become visable if you turn the steering wheel. If I were you, I would see if you can remove the cover and take a look at the switch. If you decide to give it a try, be sure to remove the battery cable first to prevent an accident. The pad the rheostat is on comes out real easy. There are 4 screws holding the lower dash panel on. Just loosen them and let the lower dash panel move a little out of the way of the pad. You dont have to take it all the way off. The pad is then held in by a few clips. Just stick a screw driver under it and use a little pressure and it will pop right out. I had mine off a couple of weeks ago and it was very easy.
Let us know how it comes out. I wish it had been one of the relays!

[YotaTruck]

So what was the resolution on this? I have the exact same symptoms: no lowbeams or marker lights, turn signals work and high beams work on flash only.

[YotaTruck]

Okay, so just to let anyone know, if they have the symptoms as described in this thread, the solution is replacement of the turn signal/dimmer combo stalk. The part was about $75 and fixed everything.


In my case the rheostat (instrument indicator dimmer) was working fine and did not need to be replaced.