Any solid advice before I start tearing up my dashboerd? Thank you.

https://imgur.com/a/hkMFY2a

That is a strange one. Have you upgraded your headlights or the bulbs recently !

 There is no headlight relay in the early Corollas. The headlight current passes through the contacts in the headlight switch on the column. I can only suggest that when the headlights are switched on, the +12V to the dash assembly drops off somewhat. The fuel guage is fed by a regulated voltage less than 12V, so that the guage always reads correctly.  Are the headlights a bit dull also. I would measure the +12V at the steering column, with the headlights on & off, & see what the difference is. The regulator for the fuel guage can use a 7, 8, or even 10 volt regulator If the head lights are dropping the +12V supply to the dash, to less than 10 volts, that may be what is causing it.. My suggestion; is to have the headlight switch control an automotive relay only. Use the relay's contact to switch the +12V directly from the battery, via a 15A automotive fuse; to the headlights.

P.S. Have a read of recent thread, which may help you shed some light on the issue.

https://www.rollaclub.com/board/topic/85671-ke55-cluster-not-working-properly/#comment-738595

Cheers Banjo 

 

Edited July 5Jul 5 by Banjo

Fit this if you haven't already-

https://www.ebay.com.au/itm/177487513731?fits=Plat_Gen%3AKE55|Make%3AToyota&_skw=toyota+ke55+headlight+relays&itmmeta=01KWTATQAZEH18AW53VFYHEBS4&hash=item2953148883:g:wf4AAeSwLYlo7Qds&itmprp=enc%3AAQALAAABAGfYFPkwiKCW4ZNSs2u11xCm4UXQkL%2BH54Zn1Fi%2FK%2FCIxUre4eicbqIcF95OZ3t96q3XP9vLhknAsfBIOe48eDFmvIJRe3bpPw%2Fz1sSKPYDumWI8AZ5SB53LcKn3Yf0j12SROuHpLD%2FLX7ytBHgGOdGenbEhBoRSsLMw7UVJsyBhS7UKjgWoslCbmI95WhAvYTFyqP87W3JUdVfdD0vHf%2BQXMAeOpUMjDi6uPdRqoBDAow93TxGrZzWFtnfwEe15Nwcz1Mlse0h8qu154ciC%2F1NqyBVjz7DXeQJFCZl7%2BG4RjBRdClkDRxIt5oGKoj25zwzDMBYnGV5WSEdLWk1aIqQ%3D|tkp%3ABk9SR-b16srmZw

It takes all the heavy current out of the dash system.  Its well worth the $30, but you can make your own with a couple of relays, which I did in The Girls KE70 many years ago.

Then I'm afraid it will be tearing the dash out and cleaning earths and contacts and checking voltages...

Hi Michalis,

                    The relay conversion, for switching the headlights on & off, will be one of the simplest, easiest modifications, You can do, for your Corolla !

Cheers Banjo

Edited July 6Jul 6 by Banjo

Thank you both.

I just ordered it and will try fitting it as soon as it arrives. 

 

That regulator Banjo mentioned is usually called an IVR, it pulses around 7 volts to the gauges so any drop on the main feed throws the duty cycle off. The relay mod should sort it right out. Got mines from CARiD, they were universal but worked perfectly on my KE70

Edited August 3Aug 3 by ToyoCoro80

On 7/6/2026 at 2:49 AM, altezzaclub said:

Fit this if you haven't already-

https://www.ebay.com.au/itm/177487513731?fits=Plat_Gen%3AKE55|Make%3AToyota&_skw=toyota+ke55+headlight+relays&itmmeta=01KWTATQAZEH18AW53VFYHEBS4&hash=item2953148883:g:wf4AAeSwLYlo7Qds&itmprp=enc%3AAQALAAABAGfYFPkwiKCW4ZNSs2u11xCm4UXQkL%2BH54Zn1Fi%2FK%2FCIxUre4eicbqIcF95OZ3t96q3XP9vLhknAsfBIOe48eDFmvIJRe3bpPw%2Fz1sSKPYDumWI8AZ5SB53LcKn3Yf0j12SROuHpLD%2FLX7ytBHgGOdGenbEhBoRSsLMw7UVJsyBhS7UKjgWoslCbmI95WhAvYTFyqP87W3JUdVfdD0vHf%2BQXMAeOpUMjDi6uPdRqoBDAow93TxGrZzWFtnfwEe15Nwcz1Mlse0h8qu154ciC%2F1NqyBVjz7DXeQJFCZl7%2BG4RjBRdClkDRxIt5oGKoj25zwzDMBYnGV5WSEdLWk1aIqQ%3D|tkp%3ABk9SR-b16srmZw

It takes all the heavy current out of the dash system.  Its well worth the $30, but you can make your own with a couple of relays, which I did in The Girls KE70 many years ago.

Then I'm afraid it will be tearing the dash out and cleaning earths and contacts and checking voltages...

Received it a few day ago and did the installation but the problem is still there. 

On 7/29/2026 at 1:44 AM, ToyoCoro80 said:

That regulator Banjo mentioned is usually called an IVR, it pulses around 7 volts to the gauges so any drop on the main feed throws the duty cycle off. The relay mod should sort it right out. Got mines from CARiD, they were universal but worked perfectly on my KE70

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