headlights

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onsight512
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Model: 1500/1600
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headlights

Post by onsight512 »

I've gone thru some (?) of the tech articles in the Wiki, but I'm lost at this point (doesn't take much with electrons).

My driver's side headlight is dim, so I started by looking for a bad ground and discovered that all three wires going to/from the headlight are hot. Is that right?
With the lights & car off all three have 12v. with the lights on & car off they have 1v, 5v, and 8v. Is that right? I assumed one would be a ground, but again, I'm mostly ignorant when it comes to electrics (but I'm trying).

I'm going to go back out and see if I can locate the HL relay. My car has an SR20 swap and so lots of stuff has been changed from original (previous owner). The HL relay doesn't see to be in the engine compartment so I'm guessing it's in the driver's side footwell where 'all of the wires' seem to end up.
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mraitch
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Re: headlights

Post by mraitch »

there is a thread in the wiki about relays OR you can purchase a set from Victoria British.

Essentially it uses the 'switching' from the stock relay but allows more 'electrons' to flow to the headlights. You will be amazed how much brighter the stock H4's are.
Peter Harrison
1970 1600 (Stroker) - TOAD SAN (Eliza)
1970 1600 (Stock) - As Yet Unnamed
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fj20spl311
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Re: headlights

Post by fj20spl311 »

They should all be HOT with the lights off.

69 & 70 cars
The headlight relay switches the ground for both lights at the same time.
My guess with the lights on they should be 0, 5, 12 with the 0 & 5 swapping on changing from high to low.

Here is a link to the wiring diagram.


http://www.311s.org/PDFs/1969-70%20Dats ... 20rev9.pdf


Red is Hot from the fuse box....should always read 12V or higher.
Red/white is high beam ground
Red/black is the low beam ground.

Because you only have 8 volt to the light, that's the first problem you need to fix.

You can try a jumper from the battery or starter to that red wire. If that cures it, look for a bad connection or wire.
You should be able to "feel the heat with you hand.....be careful not to burn yourself..... :smt059
Phil
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SLOroadster
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Re: headlights

Post by SLOroadster »

Along the same lines, I ran into a new one for me the other day. My high beams are totally gone. Low beams are fine, when I flip over to the high beams, no red like on the tach indicating the high beams are one, and no headlights at all. The tail lights work, the turn signal/running lights work, but the high beam headlights are totally gone. Low beams are fine. I doubt its the relay since when the relay wires break the headlights are in high beam only, and the red high beam warning light illuminates on the tach. I'm thinking its the actual switch that has gone bad, but I was wondering if anyone else has had this issue on a '69?

Will
Sorry, I find modern engine swaps revolting. Keep your G, R, or U series in your Roadster!
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fj20spl311
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Re: headlights

Post by fj20spl311 »

Disconnect the black/red stripe wire at the head lamp relay. If the high beams work, that wire is grounded somewhere, most likely in the T/S switch.

Do the disconnection via the plug into the T/S switch, if the high beams still work, then the ground is in the T/S switch.

You can also do these test in the other order...... :smt006
Phil
67.5 SRL311-00148 Blue (FJ cruiser VOODOO Blue)
67.5 SPL311 FJ20E teal SDS EFI
69 SRL311 SOLD
19 Raptor SCAB
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