91 dakota le no brake lights
#1
12-05-2017, 04:54 PM
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#2
12-05-2017, 06:32 PM
Champion
I'm not sure why you did the signal flasher, it's not in the brake light circuit.
But here's a couple of quick tests, which may require a friend.
1) Do you have 4-way hazards on all four corners? If yes, we can eliminate the wiring from the multi function switch (turn signal and hazard at least).
2) Presuming you do, do you have flashers in the back? If not, but you DO have hazards, that's a clear sign that the multi function switch has failed.
3) Presuming you have four way and turn signals in the back, but no brake lights, you need to check the factory service manual to verify which pin it is, but then check and see if the brake light switch is putting 12V into the MFS connector on depression of the brake pedal (hint: I'm a fat computer guy, not much upper body strength, and I can press a pedal by hand when laying on my back under the dash enough to test it.) Or, if you're not sure you can, jump the brake light switch with a jumper wire, and see what you get.
Perusing the 1990 wiring diagrams in the FAQ, it shows for 1990 it was a 18ga white wire from the switch to the MFS; I'd see if you get 12V on that line with the switch depressed. If you do, you SHOULD get 12V on the 18ga brown/red and dark_green/red wires; if not, it's most likely the multi function switch that's failed.
Aside - Download that; it should be close enough for a lot of work, beats the Chiltons and Haynes no end, and shows you what the factory service manual looks like. Then, cruise Ebay or RockAuto and pick up the FSM; used from Ebay, new at RockAuto; PDF is cheaper, and if you don't mind printing pages as you need them, could be a money saver.
(ESPECIALLY if you have hazard and turn signals, but no brakes, and if you have a center high mount stop light - a CHMSL - that does light up; well. Not much else left except the 18ga white wire being broken ... )
RwP
But here's a couple of quick tests, which may require a friend.
1) Do you have 4-way hazards on all four corners? If yes, we can eliminate the wiring from the multi function switch (turn signal and hazard at least).
2) Presuming you do, do you have flashers in the back? If not, but you DO have hazards, that's a clear sign that the multi function switch has failed.
3) Presuming you have four way and turn signals in the back, but no brake lights, you need to check the factory service manual to verify which pin it is, but then check and see if the brake light switch is putting 12V into the MFS connector on depression of the brake pedal (hint: I'm a fat computer guy, not much upper body strength, and I can press a pedal by hand when laying on my back under the dash enough to test it.) Or, if you're not sure you can, jump the brake light switch with a jumper wire, and see what you get.
Perusing the 1990 wiring diagrams in the FAQ, it shows for 1990 it was a 18ga white wire from the switch to the MFS; I'd see if you get 12V on that line with the switch depressed. If you do, you SHOULD get 12V on the 18ga brown/red and dark_green/red wires; if not, it's most likely the multi function switch that's failed.
Aside - Download that; it should be close enough for a lot of work, beats the Chiltons and Haynes no end, and shows you what the factory service manual looks like. Then, cruise Ebay or RockAuto and pick up the FSM; used from Ebay, new at RockAuto; PDF is cheaper, and if you don't mind printing pages as you need them, could be a money saver.
(ESPECIALLY if you have hazard and turn signals, but no brakes, and if you have a center high mount stop light - a CHMSL - that does light up; well. Not much else left except the 18ga white wire being broken ... )
RwP