1991 4R Headlight Issues

TT4RLtdV8

New member
Morning gents.

Spent yesterday troubleshooting the headlights on my 91. Following the advice of my searches both here, 120, and 4Crawler, I set my course of attack on the following. Before we begin, it should be noted the headlights are brand new and were installed by the PO about 2 weeks before I picked the truck up.

1) Check relays behind the glovebox. There is no audible click when the stalk is turned or pulled for the high beams. But the dash chimes if you have the lights on when you get out of the truck, so I know the light stalk isn't dead. Also the dash lights up and the dimmer dial works, sooooo yeah.

2) Check and clean the multiway switch in the steering column. I am glad I did this, even if it wasn't my direct problem. The switch was pretty gross. 25 years of dog hair, column grease, and dust took their tool and the contacts were all pretty filthy. I cleaned it up, took a file to it and got nice shiny metal.

3) Check headlights and front parking lights for 1) bulbs 2) plugged in and 3) nothing super obvious (squirrels, bags of money in between the light housing and the connections, Hilary's emails, etc). This is my first vehicle with sealed beam units, so I'm not entirely sure how to test them; but I think the multimeter will help when I get it this week.

Autozone was out of the relays that I needed, so I just ordered OEM Toyota off Amazon.. My father in law is coming sometime this week with his multimeter (I should just buy one already) and we're going to start checking that way.

Anything I'm missing here? I have front and rear turn signals and the tail lights function with the headlight switch on, which I think helps narrow it to the relays or the connections on the front of the truck.

Obligatory dismantled steering column photo.
 

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OK, so maybe I need coffee, but what exactly is the problem?
You have a ton of info but I don't see what you are trying to unfubar.

Testing headlights can be done with a test light. Remove a head light: You have 3 wires
-Ground
-Low Beam
-high beam
 
OK, so maybe I need coffee, but what exactly is the problem?
You have a ton of info but I don't see what you are trying to unfubar.

Testing headlights can be done with a test light. Remove a head light: You have 3 wires
-Ground
-Low Beam
-high beam

No worries. I typed that while drinking my first cup after a rough sleep night (the joys of a 4 week old :sleepy: :baby:) so let me clarify:



Problem: Manipulating the headlight switch does not turn on the headlights, or flash high beams. No audible click from relays either.

Solution(s): a) Dirty multiway switch in steering column b) relays are toast c) wiring issue beyond the relays

Work completed: Clean multiway in the column, check for basic installation errors from PO with headlights and relays, order new OEM relays.

Current situation: Waiting for new relays and multimeter.

Questions: Have I missed anything in troubleshooting and how do you test sealed beam headlights?

Thanks!
 
I think you have the basics covered. I don't know on the 2nd gens but the first gens have weak headlight harnesses. A lot of guys buy a replacement harness from 4crawler, Amazon, or just make their own. Not sure how much changed on the 2nd gens.


Sent from my iPhone using Tapatalk
 
congrats on the new kid, good luck with getting sleep...been there a few times myself

Were the head lights working when you bought the truck?
Why did the previous owner replace the head lights?

I recently did a head light 'upgrade' on my 94, i added a dual relay PIAA harness I had in my 81 like the fishguy mentioned. It made a big different in light output, but you need to find out if you even have power.

I know you have a meter coming to you in the future but have you tried another headlight? Standard sealed beams (even Halogen) leave a lot to be desired. You can get replacement housings that allow you to replace the bulbs.

I had a similar housing in my old 84 pick up with slightly illegal 90w/130w bulbs (transfered them to my 97 taco and melted the wiring :flamethrwoer2:)
ANyway, Hella Housing are worth the $$$
Hella 003.427-861 H4 100/80W H6054 Sealed Beam to H4 Halogen 200mm Euro Lense | eBay
 
Questions: Have I missed anything in troubleshooting and how do you test sealed beam headlights?

Yes; You do not have a schematic/FSM and no multi-meter - yet. Next to our senses, the multi-meter is the best tool for troubleshooting electrical stuff.

...There is no audible click when the stalk is turned or pulled for the high beams... But the dash chimes if you have the lights on when you get out of the truck, so I know the light stalk isn't dead. Also the dash lights up and the dimmer dial works, sooooo yeah.
This means either:
1) Stalk contacts for headlights to not close, or
2) Stalk contacts for headlights are not connected to relay negative, or
3) Stalk contacts for headlights not connected to ground.
A schematic will tell you where to test/measure voltage or continuity to ground. Toyota headlight control for older generations switch ground and not positive side.

...Autozone was out of the relays that I needed, so I just ordered OEM Toyota off Amazon..
... relays are toast..
Why did you assume the the relays are shot?
How did you know you were looking at the correct relay?
Did you check IF they are getting control signal (+12V and ground) to the coil? If they are not, they will not energize even if they are good.

Most unlikely that low-beam filament and high-beam filament of both bulbs are bad.
Since you said you said that the relays do not click and assuming that you were looking at the correct relays, If NEITHER headlight, low-beam, and high-beams work, it is not likely that both bulbs are bad. Your problem is
Relays are not getting control signal: positive 12V on positive side of the coil and ground on negative side of the coil.
Therefore, relay is not sending power (OR ground) to bulbs.
 
Last edited:
congrats on the new kid, good luck with getting sleep...been there a few times myself

Were the head lights working when you bought the truck?
Why did the previous owner replace the head lights?

I recently did a head light 'upgrade' on my 94, i added a dual relay PIAA harness I had in my 81 like the fishguy mentioned. It made a big different in light output, but you need to find out if you even have power.

I know you have a meter coming to you in the future but have you tried another headlight? Standard sealed beams (even Halogen) leave a lot to be desired. You can get replacement housings that allow you to replace the bulbs.

I had a similar housing in my old 84 pick up with slightly illegal 90w/130w bulbs (transfered them to my 97 taco and melted the wiring :flamethrwoer2:)
ANyway, Hella Housing are worth the $$$
Hella 003.427-861 H4 100/80W H6054 Sealed Beam to H4 Halogen 200mm Euro Lense | eBay

Headlights were not working when I purchased. The PO disclosed this info, so I knew this was going to be a priority #1 fix. PO replaced because the last ones were cracked/faded/gross.

In my 2nd gen research, I've seen a lot of guys do a headlight upgrade, but I haven't looked into it. I'm sure I'll get there, I just need headlights because daylight savings sucks. Dark when I drive to work, dark when I drive home.

I bought a meter on amazon this afternoon... its like, the only thing I don't have tool wise and I'm kinda over borrowing units.

I'm gonna keep that eBay link... my Christmas list is slowly being taken over by runner parts....


Yes; You do not have a schematic/FSM and no multi-meter - yet. Next to our senses, the multi-meter is the best tool for troubleshooting electrical stuff.


This means either:
1) Stalk contacts for headlights to not close, or
2) Stalk contacts for headlights are not connected to relay negative, or
3) Stalk contacts for headlights not connected to ground.
A schematic will tell you where to test/measure voltage or continuity to ground. Toyota headlight control for older generations switch ground and not positive side.



Why did you assume the the relays are shot?
How did you know you were looking at the correct relay?
Did you check IF they are getting control signal (+12V and ground) to the coil? If they are not, they will not energize even if they are good.

Most unlikely that low-beam filament and high-beam filament of both bulbs are bad.
Since you said you said that the relays do not click and assuming that you were looking at the correct relays, If NEITHER headlight, low-beam, and high-beams work, it is not likely that both bulbs are bad. Your problem is
Relays are not getting control signal: positive 12V on positive side of the coil and ground on negative side of the coil.
Therefore, relay is not sending power (OR ground) to bulbs.

Will use the in-laws meter, but I'm out out excuses as to why I don't have one. So that got purchased. I might have a FSM from a garage sale FSM vault find a couple years ago... need to go look. If not, thats on the purchase list too.


Good to know about the stalk contacts and the control signal for the relays.


Appreciate the input all. Very helpful! :clap2:
 
Awesome!
And pls scan and post schematic of your headlight circuit when you find an FSM. It helps a lot when our suggestions are illustrated, especially when it's your first time troubleshooting with a multi-meter.
A picture paints a thousand words.
 

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