Suggestions/help welcome.

pulling flatbed trailer and had no turn signals on trailer, but they worked fine or truck.

during drive, turn signals quit working on both the truck and trailer (dash light would not blink, but would turn on). Turned off the headlights and the truck and trailer signals worked fine.

plugged in the hoppy 4 wire tester. turn on parking lights, single LED works. turn on flashers, 2 LEDs flash. Turn on both headlights and flashers, only one LED.

Checked all fuses - all good. swapped relays, same performance.

test power at 4 pole connector and voltages appear to be OK with multimeter (meter can't seem to react to flashing fast enough).

Disconnect rear light harness from main harness (no truck tail lights or turn signals), plug LED tester in at the connection point (not the trailer plug) and all 3 LEDs work at the same time.

I'm at a loss.

 

Have you checked the fuses in the mini fuse block under the hood, on the left hand side, near the large fuse block. It is about 1" wide and 3" long. It will probably have electrical tape covering it.

 

2000 doesn't appear to have a mini-fuse block. all the fuses and relays were in the battery junction box under the hood.


Battery junction box (BJB) Fuse:
- 5 (20A)
- 20 (10A)
- 19 (10A)
- 101 (30A)
- 108 (30A)
Central junction box (CJB) Fuse 23 (10A)
CJB Fuse 13 (20A

 

Well, i ran all the tests from the Helm manual, continuity, ground, etc. and all test good.

Hooked a test light individually into each pin of the 4 pin connector with both running lights and flashers on and with just flashers on and the test light flashes with the same intensity.

Perhaps the hoppy tester doesnt indicate properly and the problem is really in the trailer?

 

Your truck lights working fine and lighting up the arrow on the dash shows that it is a wiring problem with the trailer somewhere. Had the same thing happen on my boat trailer.

 

Just don't understand the test light indication though

 

Hmmm... Was just re-reading. You did check BOTH fuse boxes right?

 

checked the battery junction box and the underdash box for all the trailer fuses - all were good.

 

When we have a trailer light problem at work we isolate it by using a light cart that plugs into the trailer to test the lights.
Make up a couple long test leads and use a battery to test the lights on the trailer without it hooked to the truck wiring. I would suggest putting an inline fuse in the positive lead. Then if all the trailer lights work fine you'll know it's in the trucks trailer circuit. Just remember if you test it with a battery the turn signals won't flash but should light up as bright as the brake light.
If all your fuses are fine and it's not the trailer causing the problem start tracing from the plug to the front of the truck. Could just be a bad or corroded connection behind the bumper.

 

testing with a multimeter or a tester that has LEDs wont always show the problem. If you have a bad connection or a partially broken wire these two testers can show its good when in reality its bad. The actual trailer lights draw a load and this load wont pass through the bad connection.

 

My daughter brought her Ranger home and i was able to hook the trailer up to her truck. Same symptoms - so at least i've isolated it to the trailer now.


Still don't understand the hoppy tester indications and i've not gotten a response from their tech support line yet.

So, when it quits raining, i can shoot the wires on the trailer and be back in business.

 

check the grounds on the trailer.

 

If it has 1157 bulbs in the tail lights make sure someone didn't put one in backwards.

 

Here's the email response from Hoppy

"No, they shouldn't. Only the turn signals should flash. Also... the LED tester should be used to test each function separatly and not in combination. The LEDs on the tester can not handle everything at once.

Frank Rodriguez
Technical Service
Hopkins Manufacturing Corp.
(800) 835-0129 ext. 8472

>>> "Scott Parks" <parkssa@sbcglobal.net> 11/23/07 9:11 PM >>>

I have a question about the 4 pin tester. With both the parking lights on and the flashers on at the same time, should all 3 LEDs work?

If so, any ideas why I can get the running light LED separate from the 2 flasher's LEDs, but when both functions are turned on, only the running light LED illuminates.

2000 Ford F-150"

 

Hooked up my 12v power supply to my trailer, removed all the bulbs and ran every wire. The results are in!

Blown turn signal filament on LH 1157 bulb
LH 1157 bulb install incorrectly - contacts shorting between both sides
RH tail lamp assembly loose - ground through bolts weak
AND... truck connector bad.

Repaired all last Saturday, hauled junk from church on Sunday.