Post trans swap reverse light issue
Post trans swap reverse light issue
Any ideas?
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-15-2014, 04:48 PM #1Hello all. Just replaced the transmission in my '85 300SD from the 722.315 to the spare 722.303 that came with the car. Shifts great now! Unfortunately now the reverse lights aren't working... (not 100% sure they were working in the first place) Checked the switch, that's all good. checked the harness, that's all good. Checked the fuses and bulbs, they specifically test good. I have not checked much else yet. Kinda wishing I had my wiring charts right now... One weird thing though. The "new" tranny came with an identical harness, so I just used the one that was in the car to hook it up. Then I uncovered the car's stock plug which is an 8 pin with 7 pins in it... I tested it and it's all the same pins for park and reverse. But I don't know what the 7th pin is for. Could be part of the issue idk.
Any ideas?
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
if it don’t blow black...take it back.
1982 300TDT 4 Speed 196K Standard Beige “VEGEWGN”. 300GD FW. Walbro FRC-8 Fuel Pump. ZadaTech LCD Boost, EGT, & Fuel Pressure gauge. Non-EGR Exhaust and Intake Manifold. 3/2 Valves gone. Soon to have Elsbett WVO conversion
1981 300D 314K Midnight Blue “The Blue Car”, Lovecrap system, owned 25 years+
1985 300TD White 198K “Betty White” Pure beauty
The VEGEWGN
I'm interested as well. I haven't be able to resolve a reverse light issue on my sister's 1985 300D for years. It may be the NSS switch being dirty, or not connecting properly. I will likely be ordering a replacement NSS in the near future.
if it don’t blow black...take it back.
1982 300TDT 4 Speed 196K Standard Beige “VEGEWGN”. 300GD FW. Walbro FRC-8 Fuel Pump. ZadaTech LCD Boost, EGT, & Fuel Pressure gauge. Non-EGR Exhaust and Intake Manifold. 3/2 Valves gone. Soon to have Elsbett WVO conversion
1981 300D 314K Midnight Blue “The Blue Car”, Lovecrap system, owned 25 years+
1985 300TD White 198K “Betty White” Pure beauty
The VEGEWGN
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-15-2014, 06:56 PM #3It's gotta be in the harness somewhere. I'm not sure.
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
'98 E300 Turbo "Juliette" - Brabus wheels and almost all the options a w210 could have
2007 Chevy 2500HD CCSB Duramax with about 400-500 rwhp depending on the tune I use
1983 300D Silver Exterior/Black inside - Sold and will be missed, may we never meet in a PnP.
You could swap the nss from the old trans. Make sure you have it aligned properly or that could be the issue. There's that little arm that fits into the metal shift lever on the trans and that could be the issue.
'98 E300 Turbo "Juliette" - Brabus wheels and almost all the options a w210 could have
2007 Chevy 2500HD CCSB Duramax with about 400-500 rwhp depending on the tune I use
1983 300D Silver Exterior/Black inside - Sold and will be missed, may we never meet in a PnP.
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-19-2014, 01:26 AM #5We did some poking around tonight and someone physically unscrewed the power lead to the kickdown solenoid and the reverse lights from the bottom of the fuse box... Solved the problem. But there could be some other gremlins that aren't visible yet. The lack of the kickdown solenoid might've been what screwed up the original transmission too.
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
12-20-2014, 12:28 AM #6Ugh... Now for some weird reason the reverse light etc fuse blows whenever the car is turned on... And what's even weirder is that the glow plug idiot light and relay will not click on until after the fuse is blown... There's something freaky going on here... Probly a bad ground.
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
And thank you guys for suggesting swapping the switch! I probably would have been dumb enough to never think of it myself otherwise. lol
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
dieselsmoke300d
01-06-2015, 02:51 AM #7Alright just to keep everyone up to date, I solved the problem! Turns out that all of this was caused by the transmission's shifter position switch. It was shorting internally and causing near all of the problems! All I had to do was swap it with the other one! And I'm pretty certain that was the cause of the original transmission failing in the first place (when I swapped the tranny I used the car's original switch on the new tranny and unknowingly carried the problem over). With that switch shorting everything else out on that circuit, it prevented the overload protection from working along with the reverse lights and most of all, the kickdown solenoid which caused the transmission to never downshift on its own during acceleration and then caused it to burn the bands out from straining them. Gotta love how these things work huh? lol
And thank you guys for suggesting swapping the switch! I probably would have been dumb enough to never think of it myself otherwise. lol
Matt.
'85 300SD Turbo
'92 Subaru SVX
'83 Pontiac Firebird S/E
'88 Pontiac Firebird
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