My Build Up begins: First Project=Wiring. UGH

[AxleIke]

So, I'm beginning, FINALLY, to build my truck up into what I've always wanted it to be, and in the process, I'm going to redo all of the really terrible "i'm in high school and quality means nothing" wiring jobs I've done.

However, my first concern is to get a few actual problems ironed out first.

Bear with me, because, even though I'm committed to doing this right this time, I'm still a total nincompoop when it comes to this stuff.

My first issue is that when I'm driving, at night, headlights on, and I step on my brake pedal, all of my internal lights dim, and the engine starts to run rough. I've looked as much as i can at the brake light wire, and it does not appear to be shorting anywhere. In addition, the phenomenon only occurs at night, when I'm running the headlights.

Am I looking for a short somewhere else, or something different entirely?

Thanks!

 

[bskey]

I am not great with wiring either, but the first thought that came to mind is make sure your brake lights are well grounded.

 

[Romer]

Several potentials come to mind

first - check to make sure your ground connection from the frame to the battery is clean. I had to unbolt it once and clean it up with a die grinder on my 80.

Second - Not sure if your truck has a voltage regulator, if so check your wiring to make sure connections are clean and tight. Could be the regulator needs to be replaced, not sure on that.

Third - Could be the extra load is too much for the alt to keep up with. Lots of auto shops will test alternators for free. Might be worth a try.

 

[AxleIke]

thanks guys. I'll check into those things first.

 

[Cheeseman]

Are you running stock headlights currently?

 

[RockRunner]

Are you running stock headlights currently?

Chees is right, change your headlight wiring out and either rebuild your altenator with a higer ouput coil or replace it with a 160 amp altenator.

Next check to see what all is connected to your headlights and or brake lights. Extra lights or trailer wiring will do this too.

Good luck, I really HATE electrical stuff.

 

[Rezarf]

Second - Not sure if your truck has a voltage regulator, if so check your wiring to make sure connections are clean and tight. Could be the regulator needs to be replaced, not sure on that.

x2

 

[AxleIke]

I'm running stock headlamps.

Nothing run off of the brakelight circuit. Could certainly be battery and alternator connections.

I'm going to have to look pretty deeply into the FSM to see if I've got the voltage regulator, and if so, where it is.

 

[Cheeseman]

I believe it is internal to the alternator.
________
Halfbaked

 

[leiniesred]

Tips:
Start a wiring diagram now. You'll need it in 3 years.

Go get the add-on fuse box that bolts to the battery cable on many 80's Toyotas. This way, you won't have 12 different wal-mart amp wiring kit terminals stacked up on your terminal bolts.

run a 10gauge wire to the radio area in the cab from that add-on fuse box. Connect it to a power distribution block so you can wire in the stereo, CB, HAM radio, and relays in one easy to get to place.

Plan ahead and pull wires for things you don't have yet, but plan on having someday. It is almost as easy pulling 5 wires as it is pulling 1.

In cab winch controls, ARB controls, driving light relays, rock light relays, rear power outlet, 120VAC inverter, Handheld HAM charger Stereo amplifiers, camping lights, neons, etc.




On the stumble with brakes on: On rigs our age, there is a fuel cut circuit that gets activated when the brake lights are on and the RPMs are above about 1500. When the engine revs drop below the 1500rpm or so, the computer is (supposed to) start firing injectors again. Is your idle really high? If so, then get it back down around 850. That is USUALLY the solution to the problem you are describing.

(The idea was "Why do you need to give the engine gas when you have the brakes on?" Just turn off the injectors until the engine NEEDS fuel to run."

I think the dimming headlights might be secondary to the engine not running.

 

[RockRunner]

If it is an 85 it is build into the altenator like cheese said.

 

[AxleIke]

Tips:
Start a wiring diagram now. You'll need it in 3 years.

Go get the add-on fuse box that bolts to the battery cable on many 80's Toyotas. This way, you won't have 12 different wal-mart amp wiring kit terminals stacked up on your terminal bolts.

run a 10gauge wire to the radio area in the cab from that add-on fuse box. Connect it to a power distribution block so you can wire in the stereo, CB, HAM radio, and relays in one easy to get to place.

Plan ahead and pull wires for things you don't have yet, but plan on having someday. It is almost as easy pulling 5 wires as it is pulling 1.

In cab winch controls, ARB controls, driving light relays, rock light relays, rear power outlet, 120VAC inverter, Handheld HAM charger Stereo amplifiers, camping lights, neons, etc.




On the stumble with brakes on: On rigs our age, there is a fuel cut circuit that gets activated when the brake lights are on and the RPMs are above about 1500. When the engine revs drop below the 1500rpm or so, the computer is (supposed to) start firing injectors again. Is your idle really high? If so, then get it back down around 850. That is USUALLY the solution to the problem you are describing.

(The idea was "Why do you need to give the engine gas when you have the brakes on?" Just turn off the injectors until the engine NEEDS fuel to run."

I think the dimming headlights might be secondary to the engine not running.

Ahh. Very good ideas!

I already have a lot of that stuff. My rock lights are wired with relays, i've got 3 magic arb switches, and all I need are the winch controls. No ham for a while, but you may be on to something with the NEON underglow. I've also got a single wire running from my battery to a aux fuse box. Smartest thing I've done with wiring.

AWESOME info on the fuel switch. Sounds like this may be a replace? My idle is pretty low, around 800 or so. In addition to the lights/brakes problem, occasionally the truck will stutter really badly, totally randomly, when not on the gas at all, either parked, or stopped at a stop light. I forgot about it as it hasn't done it recently, but its making me lean towards the switch being bad.

I haven't found a voltage reg, so i'm guessing i have an internal regulated unit. This is an 87, with a Toyota alternator.

Future plans may call for dual battery/On board welder. Is it worth stepping up to a 140 or 160 amp alternator now, or just wait until this one blows out?

Thanks again!

 

[leiniesred]

If your idle is OK, then it might be something else. The computer gets the brakes are on +V signal from the brake ckt. Check those grounds.

And yeah, that alternator is internally regulated.

 

[Cheeseman]

Big alternators require power to run them. I would check that out with a four cylinder if that is what you have.
________
Babe Masturbating

 

[AxleIke]

Well, haven't fixed my idle problem, but one OTHER problem thats been infrequent but annoying reared its head tonight, and got fixed.

On my way home, it was snowing, and as I was driving about 3 minutes from my place, all of my interior lights went out, as did my radio, my turn signals, and my windshied wipers, which sucked, because I couldn't see ANYTHING. Luckily I was able to drive with my head out of my window, and get it into the garage.

In the past, fuses have blown mysteriously, and then everythings worked again.

THIS was the culprit. I never noticed it because it sits under my air cleaner. Took forever to find the bugger. What a PITA. Thank goodness for propane heat!

I thought it would fix my light problem, but it didn't. Ah well, at least I'll be able to drive now!

 

[Rezarf]

Luckily I was able to drive with my head out of my window, and get it into the garage.

Hmmm...

Like this?

 

[AxleIke]

Yeah, just like that. Except for with 40mph wind, and white out blizzard conditions. My whole face hurt for an hour after I got home.

Anyway, a few minutes with a soldering iron, and some heat shrink, and problem solved.

 

[Red_Chili]

Hey Isaac, one point of design weakness with our trucks is, the ground for the headlights is routed through the light stalk on your steering column. The wire gauge is minimal, and the ground gets a bit weak. Roger Brown, 4crawler.com, sells a headlight wiring harness that switches power from the battery straight to the headlights, and only grounds the relays through the stalk. Well worth the expense, and your headlights will be brighter. This is especially worthwhile if you switch to H4 Halogens or something, but will benefit you even with Sylvania Silverstars (also very good headlights, BTW).

Order a full set of factory service manuals from Toyota. You can get a wiring book as well, with all the diagrams. Well worth the expense. Mine is near worn out. The 4Runner has a few areas of 'interest' when they get to be 30 years old (kinda like the rest of us, EH!)

Rebuilding an alternator for more output, here:
http://www.4x4wire.com/toyota/tech/alternator/

HTH,

 

[DaveInDenver]

I'm running Roger's wiring harness. He doesn't make them, they are a generic Chinese harness. Bill's right, though, I run plain old 55/60 watt H4 bulbs (mine happen to be ordinary OSRAM/Sylvania #H4ST, the motorcycle equivalent of the 9003ST) in Hella housings and they are plenty bright. The harness increased my bulb voltage by just under 1V, so there's a ton of drop in the stock harness. That difference in voltage is ~8% at the bulb, but due to the way light bulbs work, that will be about 20~25% more light (at a reduction of its life, mine last about a year typically). The bulbs I run are designed it seems for 13.2V and are rated for 76 MSCD (955 lumen) low and 125 MSCD (1570 lumen) at high. So at about 14V they are making about 95 MSCD (1200 lumen) and 155 MSCD (1950 lumen). This is closely equivalent to running roughly a 80/85 watt bulb at the lower stock voltage. The headlight harness is easily one of the best bang-for-buck upgrades you can do IMO.

 

[nakman]

x a billion on the auxillary harness. Most of the 80 faithful all run Christo's harness, I've heard of Roger's harness through Yotatech but I sold my Runner before I had the chance to buy one. Also put one on the 40 while I had it, and man what a difference... that one came from Cruiser Outfitters- I think they're pretty universal so if you feel like talking to Kurt (always a good time) maybe give him a call?