Notices
Audio / Security / Video Sound Systems, Alarms, Electronics

No constant power to head unit...?

Old 04-06-2007, 03:06 PM
  #1  
Honda-Tech Member
Thread Starter
 
Mag00n's Avatar
 
Join Date: Jan 2003
Location: UPSTATE 518
Posts: 7,987
Likes: 0
Received 1 Like on 1 Post
Default No constant power to head unit...?

My head unit is not getting any constant power. I checked the harness on the CAR side and the constant wire is only getting 0.5-2.5 not enough for the head unit to even turn on

the only way i can get it to run is if i wire the constant on the radio side to the ignition but then of course it does not remember the presets.

Anyone have any idea why there isnt any constant? Car had a system in it from previous owner is it possible they messed with it for w/e reason?
Old 04-06-2007, 04:11 PM
  #2  
Honda-Tech Member
 
94_DC4's Avatar
 
Join Date: Dec 2005
Location: 562/310, U.S.A.
Posts: 1,076
Likes: 0
Received 0 Likes on 0 Posts
Default Re: No constant power to head unit...? (.m a c a)

There are two fuses that you can test, one is in the fuse box under the dash and the other is in the fuse box under the hood. It is the radio/acc. fuse and they are both 7.5A fuses.
Old 04-06-2007, 04:40 PM
  #3  
Honda-Tech Member
Thread Starter
 
Mag00n's Avatar
 
Join Date: Jan 2003
Location: UPSTATE 518
Posts: 7,987
Likes: 0
Received 1 Like on 1 Post
Default Re: No constant power to head unit...? (94_DC4)

the fuse under the dash is fine....i didnt see a radio fuse under the hood though.....

the radio does work though so im not sure its a fuse
Old 04-06-2007, 04:52 PM
  #4  
Honda-Tech Member
 
94_DC4's Avatar
 
Join Date: Dec 2005
Location: 562/310, U.S.A.
Posts: 1,076
Likes: 0
Received 0 Likes on 0 Posts
Default Re: No constant power to head unit...? (.m a c a)

What's the make and year of the car? But there is a fuse under the hood it's 7.5A, assuming the car is a Honda/Acura.
Old 04-06-2007, 04:58 PM
  #5  
Honda-Tech Member
Thread Starter
 
Mag00n's Avatar
 
Join Date: Jan 2003
Location: UPSTATE 518
Posts: 7,987
Likes: 0
Received 1 Like on 1 Post
Default Re: No constant power to head unit...? (94_DC4)

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 94_DC4 &raquo;</TD></TR><TR><TD CLASS="quote">What's the make and year of the car? But there is a fuse under the hood it's 7.5A, assuming the car is a Honda/Acura.</TD></TR></TABLE>


98 civic almost positive there is no fuse under the hood unless it is not labeled

its getting ignition power so i dont think its a fuse problem but ill double check the hood
Old 04-06-2007, 05:14 PM
  #6  
Honda-Tech Member
 
B18C_EJ8's Avatar
 
Join Date: Jan 2003
Location: Herkimer, NY, USA
Posts: 6,565
Likes: 0
Received 1 Like on 1 Post
Default

It's not labeled radio under the hood... It's called backup or something like that...

Old 04-07-2007, 12:24 AM
  #7  
 
nel223's Avatar
 
Join Date: May 2006
Location: san jose, ca, usa
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
Default

i have the same problem on a 97 civic. underdash fuse is fine. what is the fuse under the hood called? did you get that fix? If i cant find anything.. where would be a good source to wire a constant to the head unit?
Old 04-07-2007, 05:33 AM
  #8  
fcm
Old Fart
 
fcm's Avatar
 
Join Date: May 2004
Location: kelowna, bc, canada
Posts: 26,173
Likes: 0
Received 14 Likes on 14 Posts
Default Re: No constant power to head unit...? (.m a c a)

There are two fuses, fuse 28 - 10A, [hot in acc. and run] in under dash fuse box, and fuse 47 - 7.5A, [hot at all times] in under hood fuse box.
If the fuse for the HU is bigger then 7.5A, DO NOT replace the 7.5A with a bigger fuse.
If the HU draws more then 7.5A, rewire the HUs constant power to the batt., run a 12ga fused power wire from the batt. to behind the HU and connect the HUs constant to it, the same as you would for an off board amp. 94

PS, same on the 97 nel223
Old 04-07-2007, 07:44 PM
  #9  
 
nel223's Avatar
 
Join Date: May 2006
Location: san jose, ca, usa
Posts: 27
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks fcm
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Trey Boston
Audio / Security / Video
2
03-27-2019 10:38 AM
DEEPfrom1
Audio / Security / Video
11
02-08-2009 10:03 AM
escape2me
Audio / Security / Video
7
04-26-2006 05:34 AM
4doorRS5spd
Audio / Security / Video
3
09-06-2002 08:29 PM
4doorRS5spd
Audio / Security / Video
1
08-17-2002 08:31 PM


Thread Tools
Search this Thread
Quick Reply: No constant power to head unit...?



All times are GMT -8. The time now is 07:07 PM.