Turn signal fuse keeps blowing (Page 2/2) theogre OCT 27, 07:28 PM Unplug C500 for taillights likely won't help here but doesn't hurt or eat a lot of time. Because most light wires passing thru C500 are downstream of whatever switches for a GT. If you had a notchy then there is a Jumper and wiring to "program" the brake lights. Brake lights is different circuit and fuse so problem isn't that. Could try unplug large plug to steering column. Turn switch can be bad or crap got in it but is also different circuit and fuse. Carefully take HL switch and dimmer out and unplug HL switch. Test fuse-bulb should be Off as I think HL switch is only thing downstream of it. HL Switch can be bad or can narrow down the problem there. Careful Jump Orange (Pin A) to Brown (Pin E) on the socket w/ wire then see test fuse bulb. Park Lights On? Should be but some parts likely dim and maybe too dim or "off..." But Test light at fuse is likely bright. If the Fuse-bulb is dim too maybe the switch or module is bad. (Switch won't short to ground but short inside could blow the small fuse.) Keep watching the fuse-bulb for brightness change during this items... Unplug Dimmer wheel, wheel or trans maybe shorted. See my Cave, Dash Dimmer Unplug C100 near gas pedal to isolate the entire front. Inducing Gen2 HL module that uses taillight fuse for HL down. See my Cave, Gen 2 HL Motor Unplug C500 near battery anyway... Test fuse-bulb Still On, then problem is somewhere in the cabin... Example Ashtray and lighter bulbs are on same fuse. Lighter and bulb cooks the bulb socket and wires can short to ground but like others need a HL switch to be on. HL dimmer/beam switch and most of rest of HL parts have known problems but Not on taillight circuit except Gen2 module get down wire when HL and Park lights are Off. If you think the HL module is "dead..." Very carefully unplug only the big plug. Maybe "dead" but you can kill it just by unplugging it. Solder on the module's board to the plugs are easy to crack so 1 to all pins fail and make module problems. TikiBird OCT 31, 02:26 PM Here's the recap and solution to my '87 fuse blowing issue. OK. We got the Fiero out and started digging. As they say, make a plan and STAY WITH THE PLAN. Got out the schematic and started at the 20A fuse. After the fuse, it splits in two directions: the turn signals and then the reverse light. Following the turn signal side, the turn signal flasher is first. So, we disconnected it and put in a fuse. It didn't blow. So, we're on the right track. We plugged it back in and disconnected C210 under the steering column. That should elminate everything down stream of the turn signal blinker. The fuse blew again! Went back to the schematic. THAT CAN'T BE right; the only thing in the circuit is that blinker... I took the PDF with me to lunch and continued looking at that schematic. Next thing I should check is each of the pins on C210 to make sure they're not hard-grounded. Still bugged me though. On the way home from lunch, I stopped by and picked up a turn signal blinker -- I knew that wouldn't fix it but it can't hurt either. Got home and swapped out the blinker. NO MORE FUSE BLOWNG! YaY! The blinker was an aftermarket one and the bracket had squeezed the plastic case and cracked it causing the bracket to short against the input pin. Would have NEVER guessed that to be the cause. So glad it was a simple fix. Thanks for all the suggestions and ideas. Glad to have a forum where I can ask for help. Guy at Advance Auto Parts asked, "what brand?" when I told him I needed a turn signal flasher for an '87 Fiero. Sheesh. Didn't realize that some self-proclaimed car guys don't know these gems! quote Originally posted by theogre: Unplug C500 for taillights likely won't help here but doesn't hurt or eat a lot of time. Because most light wires passing thru C500 are downstream of whatever switches for a GT. If you had a notchy then there is a Jumper and wiring to "program" the brake lights. Brake lights is different circuit and fuse so problem isn't that. Could try unplug large plug to steering column. Turn switch can be bad or crap got in it but is also different circuit and fuse. Carefully take HL switch and dimmer out and unplug HL switch. Test fuse-bulb should be Off as I think HL switch is only thing downstream of it. HL Switch can be bad or can narrow down the problem there. Careful Jump Orange (Pin A) to Brown (Pin E) on the socket w/ wire then see test fuse bulb. Park Lights On? Should be but some parts likely dim and maybe too dim or "off..." But Test light at fuse is likely bright. If the Fuse-bulb is dim too maybe the switch or module is bad. (Switch won't short to ground but short inside could blow the small fuse.) Keep watching the fuse-bulb for brightness change during this items... Unplug Dimmer wheel, wheel or trans maybe shorted. See my Cave, Dash Dimmer Unplug C100 near gas pedal to isolate the entire front. Inducing Gen2 HL module that uses taillight fuse for HL down. See my Cave, Gen 2 HL Motor Unplug C500 near battery anyway... Test fuse-bulb Still On, then problem is somewhere in the cabin... Example Ashtray and lighter bulbs are on same fuse. Lighter and bulb cooks the bulb socket and wires can short to ground but like others need a HL switch to be on. HL dimmer/beam switch and most of rest of HL parts have known problems but Not on taillight circuit except Gen2 module get down wire when HL and Park lights are Off. If you think the HL module is "dead..." Very carefully unplug only the big plug. Maybe "dead" but you can kill it just by unplugging it. Solder on the module's board to the plugs are easy to crack so 1 to all pins fail and make module problems. theogre OCT 31, 05:47 PM quote Originally posted by TikiBird: The blinker was an aftermarket one and the bracket had squeezed the plastic case and cracked it causing the bracket to short against the input pin. Would have NEVER guessed that to be the cause. So glad it was a simple fix. Sorry,,, Don't know why I switch turn for tail fuse but good to find anyway. Nearly All flasher cans are plastic now w/ most metal shells are NOS parts. ⚠️ Never put any plastic shell cans in most clips made for metal shell cans. This exact problem has been covered many times like Why would flasher break? http://www.fiero.nl/forum/Forum2/HTML/143961.html Believe Many OEM metal cans (GM Ford and likely others) were made by Tridon now sold and known as Novita in most countries. Tridon/Novita EL12 is "new" Electromechanical unit. Might still find old Thermal flashers, Novita no longer makes standard units and Thermal page only point to LL or EL equivalent. Blazer (FL32) makes an electronic flasher that works too. Most E-flasher doesn't matter whether is in normal turn or hazard like old thermal flashers. OE clip is to hold the can and make more sound. Had a Tridon EL12 but didn't see the clip so crush it in a few months... Didn't blow a fuse but didn't work. I just push the Blazer unit on top of bottom dash trim and still makes enough noise.