When I pull the hi baem stalk, noting happens. The low beams stay on. Will mt '87 service manual show the whole circuit or is a series 5 different wiring? Is there anything but the switxh or the relay in the circuit? Thanks for any help.

 

You just listed the two most probable culprits- the headlight switch and the dimmer relay...

The schematics are the same, I think...If in doubt check the wire colors against the schematics...

 

I've seen both high beams go out at the same time. Just FYI.

Pull the plug off one headlight. Make sure there is a ground on the Black wire. Then put the headlights on and see if you have 12vdc on the RED/BLACK wire on low beams then 12vdc on the RED/WHITE wire when on high beam.

You've three items. The HEADLIGHT relay, DIMMER relay and the dimmer switch in the cluster switch.

The last two relays are in front of the radiator. The Dimmer Relay the most inboard and the Headlight relay just to the Dimmer's left.

 

what about just the highbeams going out in the lamp itself
its happened to me so just another option

 

That'swhat I meat to say in my first post. The filiments for the high beam both burnt out at the same time. Low beam filiment was still good.

 

Thanks for the help guys. I'll check it out tomorrow when I'm off work.

 

If the headlight relay was kaput, he wouldn't have ANY headlights, now would he? The schematic's on page 50-48 of the FSM wiring manual, should you feel the need to refresh your memory, Hailers...

And a much easier way to troubleshoot would be to pull the connectors off of the back of the lamps, and read each pair of filiments out with a meter (on resistance). If the filiment's blown, you'll get an open.

If both lamps have an open filiment, good, it's just your bulbs. If not, it's time to troubleshoot...

 

**********need to refresh your memory, Hailers...*******************

I feel the need to send you a AGM-88. KABLOOI! BAM!POP! POW!

 

[QUOTE=HAILERS
KABLOOI! BAM!POP! POW![/QUOTE]

You watched too much of the original Batman shows when you were a kid, didn't you?

 

When I pull the dimmer switch, the low beams stay on so it's not the filaments, no matter if you watched too much Batman or not.

 

Well, you need to get a little jumper wire, and jumper the pins on the bottom of the dimmer relay where the red/green and red/white wires go into. Use a fairly large wire in this jumper, because it'll have a bit of juice flowing through it if it works...

What you'll be doing here is routing power directly from the 30A fuse, through the headlight relay, and past the dimmer relay.

If the dimmer relay is bad, this jumper will make the high beams come on...

If the wire colors aren't the same on your S5, disregard all of the above, because I don't have S5 schematics

 

Nah. Put a meter on the dimmer relays WHITE wire and see if you get a ground on it when the headlight switch is flipped. Or just shove a ground wire in the back of the WHITE wire whiile its connected to the relay and see if the high beams come on.

 

First part won't work- on the white wire, you'll read back through the relay's coil, through the contacts, and through the bulbs' filiments to ground (whether the cluster switch is working or not). You'll read something that looks like a short (making you believe you've got a ground) because of the coils & filiments...You COULD take the plug off of the dimmer relay to do this, but you neglected to mention that...Then nothing would work because you just pulled the plug off...

And the second suggestion won't work either, unless you first get the headlight relay to energize to provide power for the dimmer relay's contacts...

I'll have to assume you've been working hard on those antique F-16's, and as a result may be a little tired and mentally slow today...

 

**********You COULD take the plug off of the dimmer relay to do this, but you neglected to mention that...Then **************

Now who in the wide world of sports wouldn't pull the plug off to look for a ground when the switch is pulled???????Especially when you read the next part recommending leaving the plug on and shoving a ground wire into where the white wire is.

This car should have been fixed by now anyway.