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View Full Version : 89 and 90 high beam issue. FIXED... thanks to 91Titanium



fstcoup
07-31-2017, 08:41 PM
Both my 89 and 90 have the auto dim feature and they both will not switch to run on high beam . The flash to pass works, fog lights work and I have swapped the MFS and checked fuses. I'm unable to locate a relay on either car, Any help would be appreciated.

KMT
07-31-2017, 08:47 PM
Both my 89 and 90 have the auto dim feature and they both will not switch to run on high beam.

And this is w/auto disabled?

When you swapped MFS, did you confirm to match...green pn~code w/green; blue w/blue?

fstcoup
07-31-2017, 09:08 PM
I did. and the auto was disconnected. I completely disassembled the switch that was in the 90 car and found nothing, so I then bought another switch to be sure I hadn't missed something, installed it and still the same problem.

RalphP
07-31-2017, 09:22 PM
Silly question.

You HAVE pushed the switch ALL the way forward, right?

My Dakota has two positions - normal and pull back to change or flash-to-pass.

My COUGAR has three ... Forward is high, middle is low, and back is spring loaded flash-to-pass.

This has caught a few people before who weren't expecting it ...

RwP

fstcoup
07-31-2017, 09:37 PM
Yep.... tried it with the auto dim connected and disconnected, looked thru the chiltons manual, searched here and on line , no luck.

KMT
07-31-2017, 10:30 PM
Lighter and high beams are on the same fuse/20A circuit breaker, cavity #3 in the underdash fuse panel. Should be ok if FTP works, I'd guess, but...does the lighter work?

RalphP
07-31-2017, 10:31 PM
So you had three positions?

I ask because as I said, it's bit a lot of people before.

Well - if you have auto-dim, then there's the MFS, the high-low beam relay, and the auto dim control itself.

The high-low beam relay is supposed to be, and I quote from the 1990 EVTM, "Behind L/H side of IP, RH side of steering column." It should look like this:

http://www.tbscshop.com/automatic-headlight-dimmer-relay-1989-1997/

Past that, you really, REALLY need to crack open a EVTM (Electrical Vacuum Troubleshooting Manual) and check out sections 81, 83, and 85 specifically.

As I type this, they start at about $20 on Ebay.

RwP

fstcoup
08-01-2017, 04:21 PM
Yes three positions.....low, high and flash.

The lighter fuse is good lighter does work

91 Titanium
08-03-2017, 08:18 PM
I'm working this issue with the 89. New MFS didn't fix it, but I pulled the auto-delay / auto-dimmer switch and the high beams worked. Installed NOS auto dimmer switch and the high beams still work. That's the good news. The blue dashboard light doesn't come on. That's the bad news. I have been told the car won't pass the VA safety inspection if the blue light doesn't come on. Since that's supposed to be your reminder to keep from blinding others, that makes sense.

My EVTM hasn't arrived in the mail yet, so I can't trace it out. I'm thinking I need to leave the dash open until I figure out what is next.

Anybody have other ideas while I wait for my EVTM to arrive? I have a dimmer relay in the mail as well, which I'll install if needed. Once this is sorted, I'll look at a headlight relay to take current off the switches and avoid a recurrence.

Thx,
MP

Creighton
08-03-2017, 09:07 PM
How are the connections to the "Automatic" roller switchs? Had to clean every contact point on my 89 to get auto working. Let us know what you find. Thanks!
Creighton

91 Titanium
08-03-2017, 11:51 PM
I'm hoping I don't have to open up the switch to check, since it's NOS. Plus the blue dash light doesn't come on with the switch disconnected, while the brights do come on. I'm guessing it's a bulb or the dimmer relay, but I'll have to get the EVTM in hand to verify what's in that circuit.

MP

fstcoup
08-04-2017, 09:28 AM
If the blue high beam indicator light isn't illuminating at all it may be the bulb. If you have the instrument bezel out already it's easy to remove the four screws that hold the cluster in just rotate it out from the bottom and reach behind and pull the bulb out to check it.

91 Titanium
08-04-2017, 11:03 AM
I got the bulb out and it looks good. Not obviously blown and no break in the filament I can see. If I'm using my multi-meter correctly (a big if) I'm also seeing resistance across the bulb.

So I guess that takes me to the dimmer relay. But it's not here yet and neither is the EVTM.

Or I could just buy a bulb and see what happens. I've wondered if led bulbs in the dash are worthwhile.

MP

*Update - The contact points for the bulb looked burnt/black, so I swapped out the bulb. No joy.

91 Titanium
08-05-2017, 05:44 PM
Well - if you have auto-dim, then there's the MFS, the high-low beam relay, and the auto dim control itself.

The high-low beam relay is supposed to be, and I quote from the 1990 EVTM, "Behind L/H side of IP, RH side of steering column." It should look like this:

http://www.tbscshop.com/automatic-headlight-dimmer-relay-1989-1997/

RwP

It turns out the "high-low beam relay" isn't the part you link to. That part is the "auto lamp dual coil relay", somewhat mislabeled as "headlight dimmer" relay. We were on the same track, since I had already bought that same part before seeing your post but couldn't find it behind the IP after it arrived. Now that I have an EVTM I see that relay is on the other side of the IP next to the glovebox. I also see the auto lamp relay isn't in the direct circuit for the hi-beam indicator light in the dash, so I'll wait to swap it out later.

It looks like the high-low beam relay has one signal output for the indicator lamp that is separate from the power to the headlamps. Hopefully a new relay will fix the problem. RockAuto appears to have the high-low beam relay for about $14.

It will be next week before I can get the part and try to get it into the car. I may swap out the headlight switch while I've got everything open since I've read elsewhere on this board that they go bad over time due to the high power going through the switch.

MP

91 Titanium
08-12-2017, 02:42 PM
So I swapped out the hi-lo beam relay but still no high beam indicator light on dash.

To recap, I had no hi-beams or hi-beam indicator, but did have flash to pass.
Troubleshooting to date:
- installed NOS multi-function switch - no change
- installed NOS auto-dimmer/auto-delay switch - high beams work, no indicator light
- installed new indicator bulb - no change
- checked continuity of indicator lamp circuit per the ground check circuit from the EVTM - good continuity
- installed new hi-lo beam relay - no change

The only two headlight related items left to replace, as far as I can tell, are the headlight switch and the auto-lamp dual coil relay. From the EVTM circuit diagrams, I can't see how they could impact just the indicator light, so I doubt either of these is the issue.

I'm starting to wonder if this a problem with the instrument panel. There are other IP warning lights not working, based on failure to come on during start. Per the owner's manual, all the warning lights should come on at start-up to verify the bulb is functioning. I'm don't know why a given light would fail to come on for the test when there is a known good bulb and good continuity.

I am told the car won't pass the VA safety inspection if the indicator light doesn't come on with the hi-beams. So I essentially can't drive the car until this seemingly small issue is fixed.

Anyone out there have any ideas?

MP

RalphP
08-12-2017, 04:28 PM
The finger is bad at the back of the circuit board?

It's time to take the multi meter, kick on high beams, and follow the voltage to the indicator, I think.

RwP

91 Titanium
08-12-2017, 10:20 PM
Looking at the EVTM again, it indicated a bad headlight switch could be the cause of a 'group' of IP lights out.

I installed a new headlight switch, but no change. Still no hi-beam indicator.

Not sure if I'm capable of tracking the voltage, but we'll see. I'm still thinking something in the IP or some sort of IP relay or distribution module, but I haven't found it in the manuals yet.

MP

KMT
08-12-2017, 10:23 PM
Might be time to try another entire cluster...

91 Titanium
08-13-2017, 12:26 PM
I finally found the problem after pulling the IP gauge cluster completely out of the car for inspection.

The printed circuit flap in the left side connector was folded back and not making connection on seven leads. Putting the flap back into the socket corrected the high-beam indicator along with other warning lights that weren't working at engine start-up.

I guess I should have connected the multiple warning light issues together earlier. The overlap between that and the high-beam switch not working kept me focused in one direction when it was two unrelated problems.

Now I can get the SC out for a drive. Thanks for the suggestions along the way.

MP

KMT
08-13-2017, 12:33 PM
Glad you sorted it out. Thanks for the followup and enjoy the ride :)

Ken

fstcoup
08-13-2017, 01:05 PM
Glad to hear you were able to find the problem. As most of us here know these cars can be extremely frustrating at times, but when they're right, they're sweet.