I have a '98 XLT 4x4 with a 4.6L. I am having a problem getting my turn signals and brake lights to work on the trailer. At first glance, the fuse under the hood was blown, which I replaced and that only got the running lamps to work. I checked the RV connection at the trailer hitch with a test light and found nothing coming back. I am stumped...any help?

 

Are you working on a 4 pin or 7 pin outlet?
You need info on what fuses and relays locations are involved if you have none.
I don't know what may have changed from 99, but on my 02 I have changed from the original 4 pin to a combination 4pin/7pin harness in the rear, installed the relay and extra fuse and no problem powering a 22 ft trailer with electric brakes and all the lights.
If it worked before for you then it's just a problem but if it's a new attempt then something is missing.

 

When you say you checked the connection @ plug...did you check the trailer side of the plug (power coming out) or truck side of the plug (power going in)? If you have power before the trailer plug and nothing coming out, then possibly have problem with connection inside plug. If no power at the plug at all, then recheck the fuses under the hood. Also check for maybe a bad relay.

Hope this helps
Mike

 

I checked the 7 pin RV pin coming out of my truck (female). I took the test light and had a person in the cab turning on the turn signal and applying the brakes while I checked each pin. The brake lights and turn signals did nothing while the others caused the light to shine. I rechecked the fuses under the hood and they were all in working order.

Thanks,

Tim

 

Did you check fuse #19 and #20 under the hood. these are for the left turn/stop and right turn/stop.

 

I actually found the problem, it was a blown fuse, but it was not in either of the owner's manual described fuse panels. There was a third fuse panel which was wrapped with electrical tape hiding behind the fuse panel under the hood. I cut the tape and opened it and it held two fuses, one 5 amp and one 20 amp. The 20 amp was blown. I replaced it and Eureka!! It worked. Ford never ceases to amaze me.

Thanks,

Tim

 

Is this the Aux Fuse fuse box ?

Got this from sarebaugh.

 

Yessir, that is it.

 

See that MAXI-40 I replaced - I would double check your book , that has to do with your rear lights, I have the 98 and that one went on me once.

 

Download a 1997 owners manual, and it lists the Engine minifuse panel on page 142. Don't ask me why the 1998 printings don't list it ( even the PDF des not have it listed ).



Found this out when trying to help sarebaugh with the same problem on his 1998 over email.

He took the pictures and emailed them to me. The 1998 EVTM does not make a note of where the fuse is at fuse panel wise.

I think Steve ( projectSHO89 ) had listed the relay panel at one time. I cannot find that thread at the moment, nor am I sure that it applies to the 1998 vs. 1997s ( there was a series of changes between '97-'98-'99 that make them slightly differnet between themselves, and different from the '00 to '03 & '04 Heritage & L ).

If you don't have the sites for the PDF of the owners manuals :
www.genuineservice.com
www.fleet.ford.com
www.motorcraftservice.com

I forget which site I got my 1997 OM from, they can be different at times, with OM revisions.

 

Your prolly right , alls I saying is mine wouldn't work at all until I replaced that Maxi Fuse. I think there's two more under the dash I checked as well. When I replaced the 40 it lit up like a christmas tree.


#1 - Mini 20A = Trailer Tow Running Lamp Relay - Trailer Tow Backup Lamp Relay.
#16 - Maxi 40A = Trailer Tow Relay

Pages from the 98 book -




Like I said - mine didn't work AT ALL until I replaced that 40

Yup , my 98 book doesn't even show the other box... I'm freakin glad that fuse didn't go on me !! Thanx for the info..

 

 

Not a case of right or wrong, you and him had 2 different problems, that showed similar symptoms.
Your blown fuse was the one closer to the battery , which feed both the S/T/x bulbs and the Trailer Tow Battery Charge relay, with the Engine Minifuse Panel fuse being good.
His was the Maxi fuse was good ( and his Trailer Tow Battery Charge circuit was good ), but the 20A in the Engine Minifuse Panel was shot, so only the S/T/x bulbs were out on the trailer connector.

New add to the diagnoses Step :
jbrew problem diagnoses step for no trailer S/T/x lamps on trailer adapter -> Check the Trailer Tow Battery Charge pin for power when the key is in the run position :
No - Maxi Fuse #16
Yes - Engine Minifuse Panel fuse #2
There you go, you just added a step to the problem diagnoses that had not been around yet.

From sarebaugh I always pointed members with the similar problem to the Engine Minifuse Panel fuse, never thinking to go upstream.

Got to love 95-2 from the 1998 EVTM. Stick in that little box and call it the Engine Fuse Module

You make a vaild point, just because you hear hooves, and should think horses, does not mean it won't be a Zebra, there is a chance it could be.

 

LOL - Hell w/it - I'll just take a pic of the dang thing - make it easier on myself - Guilty - I should of read from the beginning a little slower. He said that he replaced the fuse I spoke of at first - well , I think anyway , he didn't give any numbers - I assume he has.

The 98 4x4



In the distribution box #2 and #3 - I didn't post what they were per manual

#2 -10amp = Air Bag Diag. Monitor
#3- 15amp = All Unlock Relay

The rest are posted above.

Inside the cab #18 = trailer brakes....#23 trailer tow battery charge relay


BLOCK FUSES are set up same as your discription , Y do they call them Block Fuses? There my trailer blinkers right ? idunno anymore. The 98 book never gave a description , I honestly thought Ford was kind enough to give you extras in a neat little holder haha - until I seen the wires ..

 

From 95-3, I would think this is Fuse #1 20AMP. He said that when he changed it, the running lamps started working again.

95-2 has the Maxi fuse you replaced feeding the Fuse #2 in the Engine Minifuse Panel to the S/T/x lights and the Trailer Tow BAttery Charge Relay.

Inside fuse panel Fuse #23 10 AMPs is the coil to the Trailer Two Battery Charge Relay, where the Maxi fuse is what is feed through the N.O. contacts of the relay. Fuse #23 is hot in the run position only, which is what activate the power for the Battery Charging Circuit ( 95-2 upper right hand corner ).

That is my guess at it.. ???

EDIT : For those following along, jbrew's Pages seem to be posted 95-3, 95-1, then 95-2 in post #12 above