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Headlight/high beam out on 85 FJ

Started by FJFAST, April 30, 2016, 02:58:32 PM

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FJmonkey

With a test light touch one end to your ground contact and with the other side of the test light touch the positive side of the battery. With a multi-meter you measure for voltage. I am not sure if the ignition key needs to be on for testing ground, it won't to try it both ways.
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

FJFAST

If I touch these with a tester, I get no voltage. Normal? Or a problem?

FJFAST


FJmonkey

PM sent. With the ignition switch on you should have voltage from the L/B (Blue with BLK stripe) at all times back to the negative on the battery except when starting. If you cannot measure voltage then you need work this wire back to its source till you get voltage. The wire diagram of the GYSM manual shows the Blue with black stripe as a common power. The dimmer switch pictured then directs the power to either Yellow or Green and the ground is from the black lamp plug wire. 
The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

ct7088

The blue/black wire goes to the starter switch that comes apart in a similar fashion as the hi/lo beam switch. At the starter switch the blue/black wire connects to the red/yellow wire through the switch. The starter switch has two circuits one that engages the starter and the second which turns of the headlight only when the starter is engaged. This allows all the battery's power to go to the starter. Verify there is power to the red/yellow wire at the starter switch this wire comes from the headlamp fuse and should have twelve volts when the key is in the on position. After you are satisfied that there is power at the red/yellow wire then verify there is power at the 
blue black wire if not the secondary function of the starter switch has failed. Remove the switch clean the contacts and lubricate the contacts with a heavy grease. Many people are intimidated by a wiring harness, remember only one problem at a time!

RED/YELLOW wire should have 12 volts at the starter switch (the test light should glow brightly) key is in the on position This is the next step.

BLUE/BLACK wire should have 12 volts at the starter switch whenever the RED/YELLOW wire has 12 volts

No 12 volts on the BLUE/BLACK wire means the switch needs cleaned. This can only be a simple problem but may look impossible. 

Chris
Chris

FJFAST

Ok guys, have narrowed it down (with MUCH help from FJ MONKEY,,Thank you!!) to a faulty dimmer rocker switch. Power coming in on blue/black but not going out. There was minimal corrosion when I took it apart. Cleaned it and reinstalled. Just seems like it's not making contact.
Does anyone have one from an '84-85 that they can send off to me? Just PM me for details.

I will also post in parts wanted section.

Thanks,

Greg

FJFAST

Quote from: ct7088 on May 25, 2016, 10:38:15 PM
The blue/black wire goes to the starter switch that comes apart in a similar fashion as the hi/lo beam switch. At the starter switch the blue/black wire connects to the red/yellow wire through the switch. The starter switch has two circuits one that engages the starter and the second which turns of the headlight only when the starter is engaged. This allows all the battery's power to go to the starter. Verify there is power to the red/yellow wire at the starter switch this wire comes from the headlamp fuse and should have twelve volts when the key is in the on position. After you are satisfied that there is power at the red/yellow wire then verify there is power at the 
blue black wire if not the secondary function of the starter switch has failed. Remove the switch clean the contacts and lubricate the contacts with a heavy grease. Many people are intimidated by a wiring harness, remember only one problem at a time!

RED/YELLOW wire should have 12 volts at the starter switch (the test light should glow brightly) key is in the on position This is the next step.

BLUE/BLACK wire should have 12 volts at the starter switch whenever the RED/YELLOW wire has 12 volts

No 12 volts on the BLUE/BLACK wire means the switch needs cleaned. This can only be a simple problem but may look impossible. 

Chris
Quote from: ct7088 on May 25, 2016, 10:38:15 PM
The blue/black wire goes to the starter switch that comes apart in a similar fashion as the hi/lo beam switch. At the starter switch the blue/black wire connects to the red/yellow wire through the switch. The starter switch has two circuits one that engages the starter and the second which turns of the headlight only when the starter is engaged. This allows all the battery's power to go to the starter. Verify there is power to the red/yellow wire at the starter switch this wire comes from the headlamp fuse and should have twelve volts when the key is in the on position. After you are satisfied that there is power at the red/yellow wire then verify there is power at the 
blue black wire if not the secondary function of the starter switch has failed. Remove the switch clean the contacts and lubricate the contacts with a heavy grease. Many people are intimidated by a wiring harness, remember only one problem at a time!

RED/YELLOW wire should have 12 volts at the starter switch (the test light should glow brightly) key is in the on position This is the next step.

BLUE/BLACK wire should have 12 volts at the starter switch whenever the RED/YELLOW wire has 12 volts

No 12 volts on the BLUE/BLACK wire means the switch needs cleaned. This can only be a simple problem but may look impossible. 

Chris

Hi Chris, on that side checks out..good power from R/Y and Blue/black. The dimmer switch has power coming in on blue/black and going out on green but not yellow. A fellow FJer sent me a whole switch assembly but I thought it might be a malfunctioning rocker switch so I swapped them out .no difference in output. Any suggestions?

ct7088

You are checking for voltage at the solder connection of the dimmer switch?  or at the head lamp connection?

Chris
Chris

FJFAST

It looks like it wasn't the rocker switch after all..I plugged in the new harness and have power from high and low beam wires now.

FJmonkey

The glass is not half full, it was engineered with a 2X safety factor.

'86 Ambulance - Bent frame, cracked case, due for an overhaul
'89 Stormy Blue - Suits my Dark Side

ct7088

Chris

FJFAST

Quote from: FJmonkey on June 07, 2016, 12:31:38 AM
So what fixed it?

Plugged in the "new" harness. Did not get a chance to hook up and check headlight yet tho.

FJFAST

Need help..now have power coming out of left switch..power through harness TO the Eastern Beaver setup. No power coming out from both relay setups. What M I missing?

ct7088

Check the fuse in the lead to the battery first, second verify good solid connections at the battery posts of the red and the black wires. Check that the relays are completely pushed into the sockets. You should be able to hear a slight clicking sound from the high beam relay when switching from high to low beam. Was the harness new when you got it? Relays are reliable but anything can fail.
Chris

FJFAST

Fuse good. Connections tight on battery posts. Relays solidly connected. No clicking sound. Brand new unit.