Specifications & Measurements
- Hitch ball size: 1 7/8 or 2 inch ball.
- Maximum hitch height is specified as 25 inches
- Measured natural height of trailer hitch ball receiver: 19 inches ground to bottom ( stopped by a U Haul to get this number. It applies to the hitch seen in the diagram above. Simpler version without auto safety break will be slightly lower.
- Height of the top of the square of my hitch receiver is: 14.5 inches
A rise of about 3 inches would put the hitch at the natural height. Will use the bigger ball.
- 6 x 12 foot U Haul Trailer
- UHaul 4 way flat adapter converter
- UHaul 4 Way Adapter Instructions
- Ebay: 7 Pin to 4 way adapter
My best guess is that the converter consists of some connections or resisters + connections at a minimum. Will enter what I find here later.
The trailer hitch design height used worked for a 2100 mile journey. Grateful that is over. Two Arizona trips and a trip to Washington D.C. Ouch. Now if I could only find a used Uhaul trailer. I really like this 2 axle trailer.
The right hand blinky function would not work on the trailer I purchased after I connected it the second time. Turned out the round to flat adapter must have deformed when I shoved in the adapter.
- Shake everything – no help
- connected jumper cable from chassis to trailer – no change
- Drove around the block – contrary to what was suggested the ground does not go through the metal hitch
- checked all the functions – found that only the right blinky / braking display was affected – running lights were unaffected
- Used multimeter to see that the right hand Turn / Stop function was the only connection out of the round-to-flat adapter with no signal – Green Wire
- Went and bought replacement fuses – last time I had a problem it was the fuses – Roger helped debug with his buzzy tool – replaced fuse – no change
- Used a cheap battery charger set to 6 volts to show that trailer wiring was not involved – connected to the various pins and saw all wiring good
- Now suspect flat adapter back to fuse box. Used my second adapter – Problem solved. All functions go.
Fuse Box Map
|Fuse/relay location||Ampere rating [A]||Description|
|4||10||PCM Keep Alive Memory, Instrument Cluster|
|5||10||Right Trailer Turn Signal|
|6||10||Left Trailer Turn Signal|
|8||60||I/P Fuses 5, 11, 23, 38, 4, 10, 16, 22, 28|
|9||30||PCM Power Relay, Engine Compartment Fuse 4|
|10||60||Auxiliary Battery Relay, Engine Compartment Fuses 14, 22|
|11||30||IDM Relay (1998 1/2 Vehicles)|
|12||60||Engine Compartment Fuses 26, 27|
|13||50||Blower Motor Relay (Blower Motor)|
|14||30||Trailer Running Lamps Relay, Trailer Backup Lamps Relay|
|15||40||Main Light Switch|
|16||50||RKE Module, Auxiliary Blower Motor Relay|
|17||30||Fuel Pump Relay, IDM (Diesel)|
|18||60||I/P Fuses 40, 41|
|20||20||Electric Brake Controller|
|21||50||Modified Vehicle Power|
|22||40||Trailer Battery Charge Relay (Modified Vehicles Only)|
|26||10||Generator/Voltage Regulator (Diesel Only)|
|27||15||DRL Module, Horn Relay|
|C||—||Trailer Backup Lamps Relay|
|D||—||Trailer Running Lamps Relay|
|E||—||Trailer Battery Charge Relay|
|H||—||Blower Motor Relay|
|K||—||Fuel Pump Relay, IDM Relay (Diesel)|