Hey all-

I need a hand trying to pinpoint which wires I need to check. (91 Toyota Pickup)

I added an aftermarket tach a while back and had to tap the headlight circuit so that the tach would illuminate with the headlights. Somewhere along the way, I made a mistake or caused something in the harness to loosen.

THE PROBLEM:
When I turn the headlights on, the HIGH BEAM indicator light is on, the parking lamps are on, but the headlights don't light up. However, if I press on the steering column, or fiddle with the e-brake, or just sort bang on the underside of the dashboard, sometimes the headlights come on and stay on.

If I turn on the high beams, or flash the high beams, they work fine.

I have consulted the Haynes wiring diagram and near as I can tell, either the R-Y or R-G wire must be loose. What I don't understand is why the HBeam indicator light comes on but only the parking lights illuminate unless I kinda bang around under the dash.

Thanks in advance to the kind souls who can shed some light on this problem.

 

mine does this too and have to pound the wheel to turn the lights back on. im curious to what it is. mine does it so seldomly i forget about it.

 

I would look at where you spliced the tach into the headlight circuit

Sounds like that is where the problem is.

Just how did you splice ?? Solder heat shrink ??

Does the light on the tach always come on??

 

I used one of those crimp type splices that doesn't break the tap wire, just pierces the insulation.

Good question about the tach. I will have to check to see if it lights up even when the headlights are out.

One interesting note, I must have tapped only the headlight circuit because when I turn the high beams on, the light on the tach goes out.

 

Those Scotch Lock Connectors are driving me nuts They cause more problems as those stupid trailer light converters.

It is a personal thing after 30 plus years they get me going about like watching some people try and park there SUV at the Grocery store

What they do is cut into the wire of the circuit causing that wire to break after time how fast depends on the age of the wire and just how many rough roads you bounce on.

You want to hook your tach light up to the light wire going to the Pot that dims the lights that way it will dim with your dash lights.

Nothing worse then a glaring light from the tach to destroy your night vision

 

wyoming 9-

Sounds like you're saying I should remove the scotch lock, repair the wire with solder and heat shrink, and then re wire my tach light to the pot light? I think that's a pretty durn good idea.

 

If you tapted in to the headlights, it is a negitive setup. I would have gotten the power from the radio lights or the power from the glovebox light (only has power when lights are on).

 

Glovebox light? You got the wrong truck

 

The pot light does not dim the tach, probably because the tach light simply can't dim. I ended up wiring the tach light to the tail light fuse circuit. It was easy to find and it works when the headlights are on.

 

Glad you got it working so your happy.

Strange the light would not dim any DC light with the voltage reduced should dim.

Interesting