86 Digital Dash Pulsing with Directionals
Thread Starter
Melting Slicks
Joined: Sep 2003
Posts: 3,031
Likes: 74
From: If you don't weigh in you don't wrestle Road America
86 Digital Dash Pulsing with Directionals
Hello all,
I'm working on a 86 that came to me with a dash that was dark -LCD was inop, so we sent it out for rebuild. Upon getting it back from the rebuilder and re-installing the dash the LCD pulses when the directionals are used. It's only the LCD portion not the backlights.
It will do this both when the car is running and with just the ignition in the run possition.
Things I've tried -
Charged battery cleaned the battery posts
Checked and cleaned every ground on the car - removed dash and checked both grounds going to the dash
Replaced all directional and marker bulbs, replaced both flashers
Examined wiring going to the LCD
I have had dashes rebuilt by this company before and have never had an issue (in over 10 years and probably 15 or so rebuilds). I put a call in to him but wanted to see if there was anything else that I should look for or someone has had an issue similar to this in the past.
I've done a search and haven't seen anyone with the same issue as I have here. I've also gone to batee.com and checked out some of there fixes, but didn't see anything that discribed my issue.
Thanks,
Joel
I'm working on a 86 that came to me with a dash that was dark -LCD was inop, so we sent it out for rebuild. Upon getting it back from the rebuilder and re-installing the dash the LCD pulses when the directionals are used. It's only the LCD portion not the backlights.
It will do this both when the car is running and with just the ignition in the run possition.
Things I've tried -
Charged battery cleaned the battery posts
Checked and cleaned every ground on the car - removed dash and checked both grounds going to the dash
Replaced all directional and marker bulbs, replaced both flashers
Examined wiring going to the LCD
I have had dashes rebuilt by this company before and have never had an issue (in over 10 years and probably 15 or so rebuilds). I put a call in to him but wanted to see if there was anything else that I should look for or someone has had an issue similar to this in the past.
I've done a search and haven't seen anyone with the same issue as I have here. I've also gone to batee.com and checked out some of there fixes, but didn't see anything that discribed my issue.
Thanks,
Joel
Instructor
Joined: Oct 2006
Posts: 213
Likes: 0
From: Mandeville Louisiana
The turn signal indicator lamps are a pretty heavy load relative to all of the digital stuff in the cluster. Definitely sounds like a bad connection (positive supply to cluster, cluster ground or bad solder joint on a circuit board in the cluster itself). I would measure the voltage at the positive and negative leads right at the cluster connector then actuate turn signal and see what the voltage at the connector is doing. If it's fluctuating, then the problem is upcircuit. If not, then it's internal to the cluster. If it turns out to be in the wiring, keep your negative meter lead where it was(ground feed into cluster at connector) and move positive meter lead to battery positive post. If meter reading is steady, the problem is with the positive feed. If reading is still fluctuating, you can reverse things (negative lead at battery negative post and positive lead at positive feed at cluster connector). If reading is now steady, problem is with the ground feed. This procedure will narrow things down to one of those three. From there, you would need diagrams and trace back along the affected circuit until you find the bad connection.
Jep
Jep
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
I've seen the dash pulsate when the alternator output was low. Does it still do it when you raise the RPMs up to 1500 or so?
Have you checked for cold solder joints on the dashboard connector?
Have you checked for cold solder joints on the dashboard connector?
Pro
Joined: Sep 2012
Posts: 610
Likes: 12
From: Seattle Wa
I just had the interior out of mine, and was cleaning some grounds. I came across 1 on the drivers kick panel, (I think it was kinda close to the door sill) and I disconnected it to clean it. I was looking at it thinking its so small, I wonder what it does, so I decided to turn my key on, and it did exactly what you are describing....Flashing turns, gauges flickering. So I finished cleaning, and bolted her down, (10mm I think) and turned the key again, and the gauges were all working perfectly. Maybe this will help. h
Safety Car
Joined: Mar 2005
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Likes: 1,224
From: Fredonia WI
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