Home 
> Jensen Healey & Jensen GT Tech > Electrical & Instruments > Extra Wires in JH-5 Engine Compartment

 Moderated by: Greg Fletcher  
AuthorPost
bora450
Member
 

Joined: 06-25-2013
Location: Thousand Oaks, California USA
Posts: 17
Status: 
Offline
My JH-5 is close to resurrection after and engine rebuild, transmission rebuild, and engine compartment restoration.

I’ve got some questions about the wiring harness that feeds the ignition coil. First, a friend’s early ’74 has two connectors behind the cylinder head, feeding all of the circuits. This late ’74 has one connector feeding the engine circuits and a smaller harness splitting off of the main harness near the brake booster.

This harness includes the 12 volts to the coil, shown as the short wire at the top of the photo. At the left are the green and green/black wires for the windshield washer pump. Now there are three wires that are not part of the harness in my friend’s car and were not connected to anything in my car. The white wire is energized when the ignition switch is in the RUN position and the black wire is a ground. They were wrapped together with the windshield washer pump wires and stuck out another 8 inches or so. The red/yellow wire has a round push-on female connector just like the side marker lamps. It is energized when the lights are on which makes me think that there should be an under-hood light, probably with a tilt switch incorporated in it to turn it off. But there are no holes left over for a lamp and no lamp came with the car. Could some of the later cars have an under-hood lamp attached at the windshield washer nozzle on the hood? The wire is long enough to reach.

All help to enlighten me is appreciated.
Claus

Attachment: bDSC01436.jpg (Downloaded 112 times)

Art DeKneef
Member
 

Joined: 03-12-2005
Location: Mesa, Arizona USA
Posts: 340
Status: 
Offline
I'm not sure having never seen a JH-5 but this is based on a GT I had for a while. There was a light mounted on the fender by the carbs that I imagined could possibly use some of those wires.

Also some of the later JHs and the GTs came with an anti-run on (ARO) switch that might use the wires. Unfortunately checking the wire diagrams I have here show no red/yellow wire. Are you able to trace it back farther and see what it connects to?

Maybe someone else will have the answer.

NigelK
Member
 

Joined: 07-16-2014
Location:  
Posts: 200
Status: 
Offline
If your JH-5 is fitted with a GT loom, then the white wire is the positive feed for the 4 fuses for the wipers, instruments, electric windows, fuel pump, and heated backlight. These components are only energised with the ignition on. Plus the extra length of the wire perhaps suggests it was intended to connect to the GT fusebox which is mounted on the inner wing. If the red/yellow wire is actually red/orange, then this is the positive feed for the under bonnet light, which is also mounted on the inner wing on the GT. The ARO wires are purple/white and purple/black.

Hope this helps.

Best wishes,
Nigel

Last edited on 10-04-2014 09:13 am by NigelK

bora450
Member
 

Joined: 06-25-2013
Location: Thousand Oaks, California USA
Posts: 17
Status: 
Offline
Thank you both for your inputs. The lamp wire is indeed red/orange so I'll install a light. I'll wrap the white and black wires into the harness as I rewrap it.

Thanks much,
Claus

Mitch Ware
Member


Joined: 03-12-2005
Location: Albany, New York USA
Posts: 204
Status: 
Offline
My JH5 had a wiring harness that seemed to be partially a GT loom and partially a JH loom. A couple of extra wires under the bonnet too.

Mitch Ware
#19670
#11002



UltraBB 1.172 Copyright © 2007-2011 Data 1 Systems