Since I installed my new cd player I have been blowing "istrument panel and cluster illumination fuse" as it says in my owner's manual. The wierd thing is, I have not made any changes to the system except I installed a new constant for the radio. I put a flat connector on the end of the wire so it will slip in the slots in place of the fuse, and I put it in the spot for the power door locks since I don't have power locks. Then the other night I turn my lights on and I have no dash lights but all other lights work. At first I thought it had something to do with the high beams switch beeing on the floor near the rust whole, but when I checked my fuse box the the 10 amp (that was suposed to be a 5 amp) was blown, so I put the only fuse that I had in it (it was a 5 amp) and it blew instantly, so I unplugged the constant for my cd player and took the 10 amp from my "auxiliary fuel tank selonoid and put it in the cluster illumination spot and my lights worked. So I reinstalled the constant in the fuse box, but this time I put it in the spot next to the power locks, and nothing happened, but I think the battery was too weak for the fuse to blow, so I Put the charger on the battery and am waiting.

While I wait for the battery to charge, do any of you have any suggestions as to what in the world is going on hear. If it matters any, when I was putting the cd player in I decided to also switch the light bulb from the seatbelt warning light to the parking brake warning light, because the seat belt light would never turn off, and the parking brake light is a little more useful considering my truck is a stick and I have already tried several times to drive away with the brakes on. But I noticed that the parking brake light would only come on when the key is turned all the way to the crank position. The way I found this out is the other day I noticed the light would flash when I tried to start the truck, so I disconected the starter and turned the key to the start position and held it there and the brake light was lit the hole time.

I am not sure if the 2 problems are linked, but I made the changes at the same time and never stoped to see if one worked before I did the other change.

By the way my truck is a 81 f100 with a newer 5.0 just incase you need to know. If anyone has any ideas I would like to them.

 

same problem ,same fuse it stinks and is a pain in the butt to track because the wiring diagrams are hard to find complete.( ex.from a haynes manual my 85 model used partial diagram from 80 model thru a 87. these years are broken into three sections in the manual. to help u out.....u mentioned changeing some of the bulbs... check the back side of the cluster... after the wire harness plugs into the cluster follow the wire all the way thru its route back to where it meets the harness.makes sure the plastic has not come apart. if it has this is a bad connection . kinda like a half burnt wire lead , works some of the time..also while youve got it apart take a meter and check the back of the harness for power if the meter show 1 or 2 volts from "power" to the ground ON THE HARNESS. its going to be there.my problem was the plastic pilling away. worked great till i shoved the cluster back in.. and the for some reason i had to jump the ground. instead of chaseing down where the ground went i just ran a new one ... keep in mind this is all at the back of the cluster on the harness..

 

Thanks for the info, I have been thinking of changing this cluster anywase so I could have a tack. When I take it off tomorrow to see if the junkyards cluster will work, I will look at the wiring harness back there.
This is why I love FTE, if it was not for you I probably would have torn up my fuse box, before I would even think to check the cluster wiring

Thanks again, FTE is the best!!

 

Ford has a dimmer wire from the dash (to dim the radio back lights along with the dash lights), it appears to be the radios ground wire and will work as one just fine with the lights off, but becomes hot with them on! I think, but not sure that the factory radios are grounded by the bottom mounting plate, and doesn't have a ground wire at all.

All you had to do is find a new ground for the aftermarket radio, I just attached it to bolt under the glovebox.

 

Remember you have a constant hot (Radio memory), Key hot (Radio power), and a Dash light wire to dim the radio light on the stock radio as Swatter pointed out. You have to connect these wires individually. You could be pulling more power to your after market CD player than the stock radio handled. Pull your power directly from the battery, or use a separate fuse block for aftermarket goodies. ALWAYS INLINE FUSE RADIO'S, CB'S, ETC.

 

Thanks for the info.

I have a guestion about that dimmer switch for the stock radio, is it in the same connector as the power wire for the key? If so I understand why the previous owner did not have it hooked up with the aftermarket radio he put in, he hooked his ground to the body, and I was wondering why.

My second question is if my ground being connected the way it is will prevent my dash lights from comming on even if the fuse does not blow? Because today I spent a long time trying to figure out what is wrong, and so I undid alot of things that I did while putting in the sterio (the constant, and the light bulb swap), and the fuse did not blow but my dash lights did not even come on, so I went a little further and reconected the constant, the fuse did not blow, and I still had no lights, so I removed the seatbelt light and the fuse did not blow, but I still have no dash lights. Will disconnecting the ground that I put in, and connecting it to the body bring my dash lights back?

Thanks for the help.

P.S. one-shot 24, thanks for the tip with checking the circuit board, because when I checked bach their today I found out why my alternater gage does not move, the 2 wires on the circuit board going to the gage were completely fried.

 

It is the same as the power wire connector. Its a 4 prong connector with one empty spot. One is hot, one is ACC (hot when the key is on), and one the dimmer (hot only when the lights are on).



I dont think it will, if the fuse isn't blowing anymore then it sounds like you have a mess going on. But go ahead and gound it to the body and see.

 

I am not sure if I have the right connector then. The one I have is a 2 prong, and the wire in question is light blue with a red stripe. This connector comes from the left side of the dash, and goes into the main harness near the top right of the cluster.

Also I found a connector comming from the harness that goes to the back of the cluster, it was tapped down, and I was wondering if anyone knew anything about this connector. I looked in my chilton book but all I could find was a picture of the back of the dash, and it does not say what this connector is for, but it does show another larger connector next to it and that connector is not taped down. If anyone knows what these connectors are for I am happy to listen. I have a bad feeling that one of them is for the sterio and that the po and I are using the wrong connector.

 

the light blue w/red stripe is the power source.(this is own my 85 model, ford changed very little from year to year but they did change.) and u have another connector your unsure of but u didnt mention the color of wire or wires. if it is black it is a ground if it is black w/ a green dotted line it is for the tach.just a couple of guesses as to which wire you are talking about.

 

I would never start a wiring project without using a volt meter. You cant just cut and attach on vehicles anymore. It took me 2 days to un-do the modifications that the previous owner did to my '83. When I finished, my cruise control worked again, with no other checks other than the wiring repairs.

 

According to the schematic for my 1985 F250 the Light Blue w/Red Stripe is the instrument lighting circuit line #16. it is Light Blue w/Red from the fuse box, then it changes as it feeds 6 different circuits. Yellow w/Black hash is key hot in run and acc circuit line #157. Then the Yellow w/black hash exits the radio and goes to courtesy,dome,cargo, "Lamps on Warning" circuit line #54. I will send you this schematic if you wish or go to my gallery and you can view them.

 

Holmesuser01 I agree, you should never attempt a wirring project without consulting your VOM, But I have 3 and 2 of thoes 3 are only for ac, and the third I am not sure if it even works properly, becouse according to it, the wire I am using from the key has power in the acc, and on positions but my radio anly gets power in the on position and when the constant is hooked up. So I had to do the best I could with that.



D. DeBoer,I thank you for the help with the wiring diagrams, I would like it if you could e-mail me thoes diagrams, especially the one of the fuse box, because I looked at them in your gallery but they were too small for me too read. Maybe I can enlarge them when I get them in my own computer. I will send you a private message with my e-mail. Also I noticed that thoes wiring diagrams were for 84-86, my truck is a 80 (made in november of 80) will the color codes still be the same. By the way, I like your truck, that is almost exactly what I wanted. If it had a 5spd and the long box it would be the prfect truck for me. I could not tell do you have the 6ft or 8ft bed, I like the 8 footer, it is more versitle (I think I spelled that correctly).

One last thing, my dad was wondering if the dash lights blowing has anything to do with me removing the seatbelt warning light, he thinks it could be a safety system, becouse he used to be a mechanic, and he ran into some strange systems, some cars will not even try to start unless everypart of the seatbelt system is warking correctly. Untill I get some more light bulbs I may not know (money is alittle tight so it may be awhile), but do any of you know if that could be my problem.

Thanks again everyone.