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Makotosun

1978 DT400E Wiring Harness in very sad condition

  • cdr
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Replied by cdr on topic 1978 DT400E Wiring Harness in very sad condition

Thanks for all of the suggestions.
I just received this reply from Rex’s Speedshop.
Yes we can supply a replacement loom, however I am currently awaiting a restock from the manufacturer
regards 
Venn 
Rex’s Speedshop
www.rexs- speedshop.com  
Last edit: 26 Oct 2022 18:57 by cdr.
26 Oct 2022 18:56 #11

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Replied by cdr on topic 1978 DT400E Wiring Harness in very sad condition

Hello All,

Rex's Speedshop never received any more harnesses for a 1978 DT400.

The harnesses on EBay were in rough shape, so I tried another option with a 1979 DT250 harness.

Since the 1979 DT250 has the same frame as my DT400, I decided to do a little more research to see if this harness could be modified to fit a 1978 DT400.

I bought a 1979 DT250 Yamaha service manual to identify the differences between my harness and the 1979 DT250 harness.

It turns out that both harnesses are schematically the same, except for two extra wires on the 1979 DT250 harness.  The two extra wires were taped up on both ends using self fusing tape.

The other difference is that the 1979 DT250 harness has wires that go to a flasher relay near the airbox instead of under the tank.

Some of the sheathing on the 1979 DT250 harness was coming loose, so I wrapped it with self fusing tape.

I installed the slightly changed 1979 DT250 harness, which fit very well. The new Pobit flasher relay is now located by the CDI unit under the seat.

In order to connect the new harness to items in the headlight bucket, I had to fix or repair other connectors.

The connector on the left handlebar switch had been cut off.  It was fixed by using a 4-Port Connector Housing from the Vintage Spoke.

The right handlebar switched was already replaced, because the original had shorted to ground. The new switch has an additional switch for ground. 

The nine pin connector for the 1M1-83520-00-00 1978 DT400 Tach harness was cutoff, with the remaining wires mutilated. I purchased and installed a 2A6-83520-00-00 1979 DT250 tachometer harness which fit perfectly.

The connector for the front brake switch was also cutoff, so it was replaced as well.

Most of the wires are now attached in the headlight bucket.

At this point, the blinkers, brake light, oil light, neutral light, horn, and rear parking light are now working.

I only have a few more wires to go before I can try and start the bike again. It has not run since October 2022.
  
 
The following user(s) Liked this Post: MarkT, Ht1kid, msavitt, Jewelkutter, Ju Ju400
Last edit: 13 Jun 2023 20:05 by cdr.
13 Jun 2023 20:03 #12

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Replied by MarkT on topic 1978 DT400E Wiring Harness in very sad condition

Nice job!!!
1963 YG1-T, 1965 MG1-T, Allstate 250, 1970 CT1b, 1971 R5, 1973 AT3MX, 1974 TS400L, 1975 RD350, 1976 DT175C, 1976 Husqvarna 250CR, 1981 DT175G, 1988 DT50, 1990 "Super" DT50, 1991 RT180, 2017 XT250
13 Jun 2023 20:55 #13

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Replied by cdr on topic 1978 DT400E Wiring Harness in very sad condition

Thanks
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14 Jun 2023 19:21 #14

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