Requesting Help in San Bernardino 1089 A1 Brake light, turn signal and emergency flashers not working on Expedition build.

[Adventure.Athlete]

Hello all! I have a 1999 1089A1 MTV that I have spent the last year and 3/4 building into a Expedition Truck. I have the push button light pad with service drive. Headlights and clearance light all work. I got the truck bare frame rails from Martin at FMTV sales. Great truck but it came with all the wires to the back but with no lights connected in back. I bought the LED Truck lights from MME that plug into the harness. I have them grounded as well of the rest of the harness grounded to the frame of the truck. What I'm looking for is someone with knowledge to come to the house in San Bernardino CA. and sort this out. I would think someone that knows what there doing could sort all of this out in a couple of hours. I have put in 3 days now and just not really in my skillset and patience. Willing to pay some well for solving the problem! You can text me or call at 951 259 6231 Really ready to hit the road and this is the last thing on my list.

 

[INFChief]

Neither the front or rear turn signals or 4 ways work?

 

[Adventure.Athlete]

Neither the front or rear turn signals or 4 ways work?

I have power at the brake light switches but no brake light power to the back. I only have the running lights and ground hooked up and using a test light to look for power in the wires. No blinker or emergency flashers. I ordered a flasher module and emergency flasher switch yesterday from MME and looks like they will be here Saturday. I will swap them out and test again. Thoughts?

 

[Adventure.Athlete]

Neither the front or rear turn signals or 4 ways work?

Correct

 

[INFChief]

I have power at the brake light switches but no brake light power to the back. I only have the running lights and ground hooked up and using a test light to look for power in the wires. No blinker or emergency flashers. I ordered a flasher module and emergency flasher switch yesterday from MME and looks like they will be here Saturday. I will swap them out and test again. Thoughts?

Silly questions, I apologize, but;
Do you have battery voltage through the brake light switch?
You “only have running lights hooked up”. Does that mean they are hooked up & working correctly?

Have all of the Black Out Drive lights have been removed? If so, what was done with the wiring; was it left in tact all the way to where those lights were? Or was it cut off?
Is your vehicle equipped with a backup light & does that work?
Do you know if you have voltage going to & through the 4 way hazard switch?

 

[Adventure.Athlete]

Silly questions, I apologize, but;
Do you have battery voltage through the brake light switch?
You “only have running lights hooked up”. Does that mean they are hooked up & working correctly?

Have all of the Black Out Drive lights have been removed? If so, what was done with the wiring; was it left in tact all the way to where those lights were? Or was it cut off?
Is your vehicle equipped with a backup light & does that work?
Do you know if you have voltage going to & through the 4 way hazard switch?

Yes I have voltage going through the brake light switches. The running are hooked up and are working and correct. Its seems like my electrical guy has tabled all the black out driving light labeled in back done with a test light. We didn't trace the back up light yet. I dont know if we have power going through the switch. We did test the switch and looked like the switch was working. I ordered a new one to plug in to check and see if that was it. Its now due in on Wednesday.

 

[Ronmar]

So when you step on the brake pedal does K10 energize?

 

[Adventure.Athlete]

So when you step on the brake pedal does K10 energize?

I'm away from the truck for the rest of the day but will check that first thing tomorrow! Thank you!

 

[coachgeo]

is the light switch grounded with a separate wire? It's a universal military light switch used on various military trucks. That said; there has been mentions that the push button switch .... while on some Military trucks, this switch did not need a ground ... but on the FMTV's.... it seemed too not only work far better with one.... it helped prevent issues further down the road.

 

[Adventure.Athlete]

So when you step on the brake pedal does K10 energize?

With the truck on and service drive engaged when I push the brake petal K 10 relay greed light comes on! I did swap out the relay just to double check. The back are wired as per the diagram with nothing for stop light, turn signals or emergency flashers, Thoughts?

 

[Ronmar]

With the truck on and service drive engaged when I push the brake petal K 10 relay greed light comes on! I did swap out the relay just to double check. The back are wired as per the diagram with nothing for stop light, turn signals or emergency flashers, Thoughts?

As long as the relay is going click along with that green LED…

On the A1, Power From CB71 passes thru the energized contacts of K10, thru the steering column switch and thru the DE-ENERGIZED(pin 87A-30) contacts of K21 and K22 (left and right rear light relays) And on to the rear lights. The outputs of K21&22 also feed the coils of K30&31(trailer relays) so they should also energize along with K10 When you step on the pedal.

If they do not? Is CB71 delivering power to socket 87 of K10? Are K21 and 22 5 pin relays? You must have 5 pins to have the de-energized circuit path. Pull K21&22 and with K10 energized you should see 12V on socket 87A for both those relays. If you do not the issue is probably in the Column switch. If it is there and K30& 31 are energizing, the problem is downstream, as the flow is from pin 30 of K21 &22 directly to the left and right rear brake/turn lights…

 

[Adventure.Athlete]

As long as the relay is going click along with that green LED…

On the A1, Power From CB71 passes thru the energized contacts of K10, thru the steering column switch and thru the DE-ENERGIZED(pin 87A-30) contacts of K21 and K22 (left and right rear light relays) And on to the rear lights. The outputs of K21&22 also feed the coils of K30&31(trailer relays) so they should also energize along with K10 When you step on the pedal.

If they do not? Is CB71 delivering power to socket 87 of K10? Are K21 and 22 5 pin relays? You must have 5 pins to have the de-energized circuit path. Pull K21&22 and with K10 energized you should see 12V on socket 87A for both those relays. If you do not the issue is probably in the Column switch. If it is there and K30& 31 are energizing, the problem is downstream, as the flow is from pin 30 of K21 &22 directly to the left and right rear brake/turn lights…

Update! I grabbed a brake light signal from the 7 pin connector and have brake lights! I ordered a flasher module and Emergency Flasher switch do in on Wednesday! I really hope that solves the blinker problem!

 

[Ronmar]

Ok, on the A1 they tapped off brake switch power directly to feed the trailer plug, which bypasses all the other wiring. It is the same brake power that activates K10 When you step on the pedal.

One of the reasons I like to concentrate on one problem when there are multiples is that in fixing one, you often find the root cause of other problems.

hacking brake light power out of the trailer connector may have gotten you brake lights, but the truck itself does not use a standalone brake light circuit. It uses two(left and right) combined brake and turn circuits. It is these same combined 12V brake/turn signals that are output to the 7 pin trailer connector for the trailer turnsignals, So untill you have brake lights via the normal pathway, you will never have turn signals.

It may be that there is nothing wrong with your flasher, and the same thing keeping you from normal brakes is keeping you from normal TS…

So back to my last question, do K30 and K31 energize along with K10 when you step on the brake pedal?

The purpose of K30 and 31 are to take the 12V TS/brake signals and use them to switch a 24V trailer signal thru the relays to the 24V 10 pin trailer connector. They should both come on with brakes and pulse with hazard flashers, or one should come on with it’s associated left/right TS appliction…

 

[Adventure.Athlete]

Ok, on the A1 they tapped off brake switch power directly to feed the trailer plug, which bypasses all the other wiring. It is the same brake power that activates K10 When you step on the pedal.

One of the reasons I like to concentrate on one problem when there are multiples is that in fixing one, you often find the root cause of other problems.

hacking brake light power out of the trailer connector may have gotten you brake lights, but the truck itself does not use a standalone brake light circuit. It uses two(left and right) combined brake and turn circuits. It is these same combined 12V brake/turn signals that are output to the 7 pin trailer connector for the trailer turnsignals, So untill you have brake lights via the normal pathway, you will never have turn signals.

It may be that there is nothing wrong with your flasher, and the same thing keeping you from normal brakes is keeping you from normal TS…

So back to my last question, do K30 and K31 energize along with K10 when you step on the brake pedal?

The purpose of K30 and 31 are to take the 12V TS/brake signals and use them to switch a 24V trailer signal thru the relays to the 24V 10 pin trailer connector. They should both come on with brakes and pulse with hazard flashers, or one should come on with it’s associated left/right TS appliction…

Thank you!
I'm doing my best to follow this and will check it tomorrow.

 

[GTUnit]

Does anyone have a lighting wiring schematic related to this part of the truck?

 

[Ronmar]

Does anyone have a lighting wiring schematic related to this part of the truck?

What truck? The A0 and A1 schematics are in the pubs section at the top of the main forum page under present conflict vehicles. The A0 are in the back of each manual found there, the A1 is just a schematic by itself, no manual…

 

[Adventure.Athlete]

What truck? The A0 and A1 schematics are in the pubs section at the top of the main forum page under present conflict vehicles. The A0 are in the back of each manual found there, the A1 is just a schematic by itself, no manual…

My truck is a 1089 A1. I added a L.E.D. flasher module and ran new wires to the back amber trailer lights. Works for now and works every time! LOL! I just got back from my first camping trip with the truck! So far It is perfect for what I want to do! A Beast off road for sure with the two rear lockers! Thank you all for the help.