Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help

Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Diesel Discussion

LinkBack Thread Tools Display Modes
Old 09-13-2008, 10:20 PM
Registered User
Join Date: Apr 2005
Location: East Toadsuck Vermont
Posts: 61
Wiring whoas

I am somewhat electrically challenged.i may have gotton in to deep
with this project.
Problem: I have no dash lights ,power windows sunroof ,temp fuel gauge,
blinkers indicators
all these worked before project.
Project :Install frybrid system. in 79 300sd w116.

At some point during this project i tried starting the car and the glow plug
indicator light did not work .Subsequent testing showed glow plugs seemed to have normal resistance (all under 1 ohm) ..12 volts to relay and across fuse
But not to glow plugs.I had to reroute this wiring harness while doing the install even though i got resistances across all wiring I decided to replace
the gp relay system with a simple starter relay and a dash button that i saw on this site somewhere.Results where excellent.I also replaced the Glowplugs
and car starts great.

Still no power to anything electrical.(no blinker indicators..fuel gauge ,temp sensor ,power windows,sunroof etc)
In doing this install I had to pull the climate control panel out of the center console in order to route wiring from the ashtray area to the frybrid controller
i have put all the gauges and lights for the frybrid system in a panel
and installed it in the ashtray area as there is a switched 12v power source and ground there from the ashtray/lighter.
I needed to run a wire to the back of the car so i clipped one off
the power antenna(this was replaced by the previous owner) with a stationary antrenna) . I figured i could use this unused wiring for my
sending unit in the wvo tank located in the trunk rather than route new
wiring. My wiring problems were apparent to me before i did this.
So i do not think this is an issue here. just added it to be compleat

I am giving you all as much info as i can as to what i may have screwed up.

In looking in the fusebox located in the engine bay drivers side firewall
I have a blown fuse in the number 4 slot that blows when i replace it
as soon as i turn on the key. I would not think all electrical systems
in this car would run off one fuse. But what do i know?

The frybrid controller, lights, gauges all function as designed so i do have some switched power but this is isolated from the rest of the car(with the exception of the switched power in the ashtray).

So my questions could be but not limited to.
1. could i have disconnected something crucial in removing the glow plug relay from the system.
My thoughts here are that the lack of power may have been the problem with this relay in the first place..
2. Have i blown some other main circuit thingy somwhere else.
I read somewhere about an OVP "Over voltage protection" relay.
Not sure if this applys to a 79 300sd or not.
If so where is this ovp located on my car ??

Reply With Quote
Old 09-14-2008, 03:47 AM
Registered User
Join Date: Apr 2005
Location: East Toadsuck Vermont
Posts: 61
any one got any ideas
Reply With Quote
Old 09-14-2008, 08:33 PM
Diesel911's Avatar
Registered User
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 29,900
I think no one has answered as maybe someone would have to actually be there with you to help unravel what was done and find out what has happen.

When I used the Starter Relay to replace the Glow Plug Relay on my Volvo I wired it directly to the battery. If you did that it should not interfere with any of the other stuff.

As for what possibly happend it could be 1 of or all of the problems you listed including a ground could have been disconnected.
If you had the Manual the Wiring Diagram would probably tell you what colored wires go to where and you trouble shooting would be eased some.
I am always inclined to look at the fuse box first and see if anything happend there. If fuses are burned something got short circuited.If the Fuses are OK I verify that the Fuse Box is getting battery voltage.
Also take a good look at the wires inside of the Fuse Box. I had a wire that looked OK but when I pulled a little I found that it was actually not soldered down any more and If I remember it was a Green Ground wire inside of the Fuse Box.

Also some electrical items pull too many Amps to be wired to the Accessory part of the ignition switch.
Best wishes.
84 300D, 82 Volvo 244Gl Diesel
Reply With Quote
Old 09-15-2008, 12:12 AM
Registered User
Join Date: Apr 2005
Location: East Toadsuck Vermont
Posts: 61
I did wire the relay to the battery hot wire that came off the old relay.
and the new relay is working fine.
Plus all the new stuff that is tied into the switched 12 v is working.
I found out today that the sunroof and passenger side windows are working
so it is just the blinkers, dash lights fuel and temp gauge and drivers window not working . i will have to see if i can dig up a diagram.. sounds fuse related though and the number 4 fuse does keep blowing.can't imagine where it could be shorting. I wonder if when i pulled the climate control panel out i pulled a clip loose and it's shorting back in there???hmm??
I shouldn't be allowed(sic)to have so much fun..
Reply With Quote
Old 09-15-2008, 12:51 AM
Diesel911's Avatar
Registered User
Join Date: Sep 2007
Location: Long Beach,CA
Posts: 29,900
I don't like or have a knack for electrical problems either. Just 1 wire for 1 circuit covers a lot of territory and runs through and behind a lot of other components.
I actually have a 14 foot test lead with an Alligator clip on each end so that I can by pass all the in between stuff and see if can get it working hooked directly to the battery.
Also fuses can be deceiveing; this one looked good until I pulled it; it is on of the window fuses.

The green wire in this pic looked OK but the solder had come loose on it.

84 300D, 82 Volvo 244Gl Diesel
Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

All times are GMT -4. The time now is 09:13 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page